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THE 

ZYGNEMATACEAE

THE 

ZYGNEMATACEAE 

(FRESH-WATER CONJUGATE ALGAE) 

With Keys 

for the Identification of Genera and Species 

and 

Seven Hundred Eighty-Nine Illustrations 

vGVWi .^X 

By 

Edgar Nelson Transeau 

Emeritus Pro]essor of Botany 

The Ohio State University 

THE OHIO STATE UNIVERSITY PRESS 

Columbus 

1951

GRADUATE SCHOOL MONOGRAPHS 

Contributions in Botany, No. i 

Copyright 1951 

The Ohio State University 

Columbus 

Printed in 

United States of America

jOdi, 

To the Graduate Students 

who discovered many new species and 

extended the known range of many other 

Zygnemataceae

INTRODUCTION 

The absence of a modern general key with detailed descrip- 

tions of the species belonging to the Zygnemataceae has greatly 

retarded the study of this family. This volume, it is hoped, will 

furnish a better manual for the identification of the genera and 

species than has been previously available. It seems self-evident 

that any studies of life histories, seasonal and cyclic abundance, 

and geographic distribution must be based on the accurate naming 

of the species considered. In addition to the literature about the 

Zygnemataceae, the present descriptions are based on data and 

specimens accumulated over a period of thirty-five years. 

My interest in the group was originally stimulated by Mr. 

Frank S. Collins, who sent me many specimens he had collected, 

or received by exchange. These specimens were soon augmented 

by exsiccatae from Professors Borge, Nordstedt, Farlow, and 

Thaxter. These included numerous type specimens from many 

sources, and made possible the revision of earlier descriptions 

and the devising of new keys for the separation of species. Meanwhile, 

thousands of collections became available for study through 

the collecting activities of associates, graduate students, and myself 

throughout the eastern half of the United States, and from 

Ontario to Cape Breton Island. From Finland, Latvia, South 

Africa, Central and South America, Puerto Rico, China, India, 

Japan, and the Philippine Islands, several hundred additional col- 

lections have been received from correspondents. During the 

most active period of the study of these collections, I had the 

assistance of Professors L. H. Tiffany and C. E. Taft, who checked 

literally scores of the determinations and verified numerous de- 

scriptions of new species. To them I am most grateful for their 

help, and for the feeling of satisfaction that the new descriptions, 

particularly of spore walls, have been verified by at least one 

other pair of eyes. 

Whether one accepts all of the genera, or all of the species, as 

valid or not, they seemed to differ in enough particulars to war- 

rant their separation at the time they were studied. Some of the 

species described during the early history of the group have been

viii 

ZYGNEMATACEAE 

omitted because of faulty descriptions. Also some recent descrip- 

tions have had to be passed over because they lacked important 

details, or because of discrepancies between figures and descriptions. 

I have no doubt that some of these species are valid, and 

if additional information could have been obtained, they would 

have been included. No attempt has been made to guess at the 

synonomy of all previously published species names. Such guesses 

can be found in the Sylloge Algarmn by G. B. de Toni (1889), in 

the Siisswasserjiora Mitteleuropa, 9 (1932), and in Rabenhorst's 

Kryptogamenfiora, 13 (1941-44), abt. II. In the absence of 

complete descriptions, or of the actual specimens, such conjectures 

seem gratuitous. Synonyms that are the result of different con- 

cepts of generic or specific limits are usually given. A few species 

with incomplete descriptions, but with conspicuous structures 

that distinguish them from other somewhat similar species, have 

been retained. 

Among the many friends and students who have contributed 

collections containing Zygnemataceae, I am particularly indebted 

to Alma Ackley, Wayne University; Charles C. Adams, New 

York State Museum; D. B. Anderson, Agricultural and Technical 

College of North Carolina; the late W. M. Barrows, The Ohio 

State University; Glenn W. Blaydes, The Ohio State University; 

E. T. Bodenberg, Wittenberg College; Harold C. Bold, Vander- 

bilt University; Helen B. Bromley, Stamford, Connecticut; 

Charles Bullard, late of Harvard University; C. Cedercreutz, 

Helsingfors, Finland; Glenn Couch, University of Oklahoma; 

Francis Drouet, Chicago Natural History Museum; R. B. Gordon, 

Westchester Teachers College; Lawrence Hicks, Columbus, 

Ohio; Elwyn Hughes, University of Oklahoma; G. J. Ikenberry, 

Oklahoma Agricultural and Mechanical College; Chin-Chih Jao, 

Chungking, China; Minnie M. Johnson, Stephens College; Ivey 

Lewis, University of Virginia; Liang Ching Li, Fan Memorial 

Institute of Peiping, China; Floyd A. McClure, Lingnan Uni- 

versity; B. B. Mclnteer, University of Kentucky; George Nichols, 

late of Yale University; Claude E. O'Neal, Ohio Wesleyan University; 

Gerald Prescott, Michigan State College; M. S. Rand- 

hawa, Fyzabad, India; H. C. Sampson, The Ohio State University; 

H. Skuja, Uppsala University, Sweden; Ben H. Smith, Indiana 

State Teachers College; G. M. Smith, Stanford University; Edith 

L. Stephens, University of South Africa; E. L. Stover, Eastern

INTRODUCTION ix 

Illinois State Teachers College; Clarence E. Taft, The Ohio State 

University; Hiram Thut, Eastern Illinois State Teachers College; 

L. H. Tiffany, Northwestern University; and Larry Whit- 

ford, Agricultural and Technical College of North Carolina. 

In checking the descriptions, keys, and references, I had the 

assistance of Mrs. Maynard Hale and Mrs. Robert Sigafoos. They 

added much to the accuracy of the text, the indexing, and the 

uniformity of the references. Professor John L. Blum of Canisius 

College, Buffalo, copied or adapted many of the published figures 

and added many new figures and details of spore walls. Without 

his help the publication would have been greatly delayed. I am 

grateful to each of these associates for their contributions to the 

usableness of the keys. 

The Graduate School of The Ohio State University has aided 

in the editorial work, and in the preparation of the figures and 

plates. It is a pleasure to acknowledge this financial assistance. 

No attempt has been made to draw the figures to a certain 

scale of magnification. Since the descriptions give the dimensions, 

the principal value of the illustrations is the form of the various 

structures associated with reproduction and the details of spore- 

wall markings. The 789 figures illustrate 534 species, and all of 

the known types of gametangia and spores. 

Columbus, Ohio 

1950 

E.N.T.

Chapter 

CONTENTS 

Page 

I. General Taxonomic Characteristics—The Order Zygnematales 

G, M. Smith 1933 3 

II. The Genus Zygnema C. A. Agardh 1824 13 

III. The Genus Zygnemopsis (Skuja) Transeau 1934 49 

IV. The Genus Hallasia Rosenvinge 1924 61 

V. The Genus Zygogonium Kiitzing 1843 63 

VI. The Genus Pleurodisciis Lagerheim 1895 71 

VII. The Genus Mougeotiopsis Palla 1894 73 

VIII. The Genus Debarya Wittrock 1872 75 

IX. The Genus Motigeotia C. A. Agardh 1824 79 

X. The Genus Temnogametum W. & G. S. West 1897 117 

XI. The Genus Sirocladium Randhawa 1941 119 

XII. The Genus Entransia Elwyn Hughes 1943 121 

XIII. The Genus Spirogyra Link 1 820 123 

XIV. The Genus Sirogonium Kiitzing 1843 231 

Index 239 

Plates 247

Plat€ 

ILLUSTRATIONS 

Plates 

Page 

I. Reproductive Structures of Zygnemataceae 246 

II. Zygnema 248 

III. Zygnema 250 

IV. Zygnema 252 

V. Zygnema 254 

VI. Zygnema 256 

VII. Zygnema 258 

VIII. Zygnemopsis 260 

IX. Zygnemopsis 262 

X. Hallasia and Zygogonium 264 

XI. Zygogonium 266 

XII. Zygogonium, Pleurodiscus, Mougeotiopsis, and Debarya. . 268 

XIII. Mougeotia 270 

XIV. Mougeotia 272 

XV. Mougeotia 274 

XVI. Mougeotia 276 

XVII. Mougeotia 278 

XVIII. Mougeotia 280 

XIX. Mougeotia 282 

XX. Temnogametum, Sirocladium, and Entransia 284 

XXI. Spirogyra 286 

XXII. Spirogyra 288 

XXIII. Spirogyra 290 

xiii

xiv ZYGNEMATACEAE 

Plate Page 

XXIV. Spirogyra 292 

XXV. Spirogyra 294 

XXVI. Spirogyra 296 

XXVII. Spirogyra 298 

XXVIII. spirogyra 300 

XXIX. Spirogyra 302 

XXX. Spirogyra 304 

XXXI. Spirogyra 306 

XXXII. Spirogyra 308 

XXXIII. Spirogyra 310 

XXXIV. Spirogyra 312 

XXXV. Spirogyra 314 

XXXVI. Spirogyra 316 

XXXVII. Spirogyra 318 

XXXVIII. Spirogyra 320 

XXXIX. spirogyra 322 

XL. Sirogonium 324 

XLI. Zygogonium, Zygnema, and Spirogyra 326 

Illustrations in Text 

Figure Page 

A Zygnema ellipsoideum 44 

B-C Zygnema mirificum 44 

D-E Zygnema l{hannae 45 

F Spirogyra crassa 193 

G Sirogonium sticticum 233 

H-K Sirogonium phacosporum 236

THE 

ZYGNEMATACEAE

CHAPTER ONE 

GENERAL TAXONOMIC CHARACTERISTICS 

The Order ZYGNEMATALES G. M. Smith 1933 

The plants belonging to this order of the Chlorophyta differ 

from all other green algae in the absence of free swimming flagel- 

lated gametes and spores; sexual reproduction is consummated by 

amoeboid gametes through, or within, a tube, pectic sheath, or an 

enveloping pectic mass. 

The plants consist of single cells, of loose cell aggregates within 

a pectic gel, or of unbranched or very sparsely branched, and 

usually undifferentiated, filaments. The cell walls have an outer 

pectic layer and an inner cellulose layer. The spore walls consist 

of at least three layers, the inner and outer of which are of cellu- 

lose, and the median wall of cellulose with varying amounts of 

chitinous deposits. The median wall may be colored yellow, 

brown, or blue. 

The chromatophores may consist of axial or parietal plates, or 

spirally arranged parietal ribbonlike structures, or of two axial 

stellate bodies often highly diversified among the desmids. 

The zygospores have a dormant period during which there is 

a fusion of the gametic nuclei followed by a reduction division. 

At the time of germination the four resulting nuclei may each 

become the center of a new cell, or two or three of the nuclei may 

disintegrate and only two or one sporelings emerge from the 

spore wall. 

The Zygnematales are naturally divided into three families 

which have, briefly, the following characteristics: 

FAMILY I. ZYGNEMATACEAE 

These are filamentous plants, usually unbranched, and have 

cylindric cells. The walls of the vegetative cells are unsegmented 

and without pores. The chromatophores are either axial 

more or less stellate, ribbonlike or platelike bodies; or are parietal 

platelike or spirally arranged ribbonlike bodies. Conjugation of

4 

ZYGNEMATACEAE 

gametes is by means of a tube between the gametangia, or sometimes 

by a mere opening between the adherent gametangia. The 

zygospores are formed either in the tube or within one of the 

gametangia. 

FAMILY 2. MESOTAENIACEAE 

Vegetative cells are solitary, cylindric or spindle-shaped, or 

sometimes loosely united into filaments within an amorphous 

pectic gel or pectic sheath, and without wall pores. Chromato- 

phores are stellate, platelike, or ribbonlike and spirally arranged. 

Conjugation of gametes occurs through tubes of cellulose, or 

within a pectic gel. 

FAMILY 3. 

DESMIDIACEAE 

Vegetative cells are solitary, or sometimes are united into 

simple filaments. Vegetative cells have highly diversified and 

sometimes bizarre forms, but all have transversely segmented 

walls and wall pores. In most genera the cells have a median con- 

striction or isthmus between the two nearly symmetrical halves. 

There may be one or several chromatophores in each semicell 

with a nucleus in the isthmus. During cell division, after the 

nucleus divides, the isthmus elongates and the two semicells are 

separated by a median wall. On both sides of this wall new semi- 

cells develop from the isthmus. Conjugation is by gametes that 

emerge from their respective cell walls and unite within an amorphous 

pectic sheath or in a conjugating tube. (For further details 

see G. W. Prescott, "Desmids," Botanical Review, 14 [1948], 

pp. 644-76.) 

The Family ZYGNEMATACEAE Smith 1933 

The species belonging to the Zygnemataceae are probably more 

numerous, and are more generally distributed over the earth than 

those of any other family of filamentous green algae. The tangled 

green masses of algae floating on ponds, ditches, and slow streams 

anywhere are sure to contain representatives of this group. 

All the species have cylindric cells during the period of vege- 

tative growth. During the reproductive period, however, the cell 

walls of some species grow and change their size and form in a 

most astonishing manner. In some species the gametangia alone 

are affected. The receptive gametangia in particular may become 

distended on all sides, on the conjugating side only, or only on

TAXONOMIC CHARACTERISTICS 5 

the opposite side. The bulges may be rounded, or cylindric with 

shoulders at both ends, or spindle-shaped. In any event the 

resulting forms of the expanding cell walls are remarkably uniform 

in a given species. In other species many of the nonreproducing 

cells enlarge and become distended or even bullate. These 

changes in cell form are definitely the result of hereditary factors. 

In some environments one may also find vegetative filaments 

composed of variously rounded or distorted cells, even with rhi- 

zoidlike outgrowths, in extreme instances. These collections, in 

my experience, have always been gathered from ponds with warm 

water and low oxygen pressure. Since these effects were noted on 

several of the species present, the causes are probably environ- 

mental. 

The following key to the genera is based primarily on the 

characteristics of the chromatophores, and secondarily on the 

changes that take place in the reproductive cells during spore 

formation. 

In the subsequent keys to the species grouped under each genus 

stress is laid on the characteristics of the spores. Consequently one 

must be quite clear about the nature of these several kinds of 

reproductive structures. 

The simplest, most universally present, and probably the most 

primitive type of propagating cell is the akjnete (PI. I, Figs. 1-3). 

This is usually just a vegetative cell, the walls of which have been 

thickened by additional layers of cellulose, or cellulose and pectose. 

These cells survive long periods of drought, high and low tem- 

peratures, as well as the effects of these factors on the concen- 

tration of solutes in their immediate environments. Akinetes 

germinate readily and initiate new filaments. Only one species 

(Zygiiema sterile) has been found to reproduce by this method 

alone. There are probably many others but they are not so easy 

to identify as this one, which happens to be the largest species of 

Zygnema in the Ohio valley. 

There is a prevalent notion that akinetes are formed when 

conditions are unfavorable. It has been our experience that they 

develop both when conditions seem most favorable and when 

least favorable. In cultures, they appear both at high temperatures 

and low temperatures. The causes for the initiation of akinetes 

are best stated as unknown. 

At high altitudes and latitudes the species of Zygnemataceae

6 ZYGNEMATACEAE 

are common but are rarely found producing spores. These species 

cannot be identified because the modern species keys are necessarily 

built around spore characteristics. Akinetes are common 

in collections from these short-season regions, and by means of 

them survival and propagation of many species take place. There 

is no good reason to assume that all these species would produce 

spores in other environments. It is far more likely that some of 

these species are wholly vegetative, or akinetic. 

There are other species in several of the genera that also reproduce 

by aplanospores. These are slightly more specialized than 

akinetes. Their forerunners are vegetative cells, the protoplasts 

of which have contracted more or less, and in which new walls 

of cellulose, with or without chitinous deposits, have developed. 

The spore walls may be colorless and smooth, or variously colored, 

sculptured, and ornamented. The criteria used to distinguish 

aplanospores in Zygnematales are precisely the same as those used 

to designate aplanospores among the Ulotrichales (PI. I, Figs. 4-7). 

Of the species here described, thirty-seven reproduce regularly 

by aplanospores, and zygospores have been found in the same 

filaments only rarely. Scattered aplanospores also occur along 

with zygospores in seventy-six additional species which belong to 

7 genera. Moreover, only a few algologists have been interested 

in looking for aplanospores or the list probably would be larger. 

When found, aplanospores have often been written off as algal 

errors, since most authors state definitely that none of the species 

of Zygnemataceae "forms asexual reproductive bodies" (Smith 

1933), or suspect that they are the result of lateral conjugation 

(Czurda 1932). The "lateral conjugation" theory rests on statements 

by Petit (1880), W. & G. S. West (1902), with a figure of a 

disintegrating chromatophore, and figures by Czurda (1931), 

without nuclei and also with disintegrating chromatophores. The 

latter series of figures seems to prove only that this unnamed 

species of Mougcotia may have under experimental conditions 

lateral conjugation, as have 6 other species in nature. It has little 

or no significance in proving that the numerous aplanospores 

occurring in nature which have been carefully studied during 

their entire development are zygospores. 

Zygospores result from the union of gametes that are more or 

less similar in appearance, but physiologically different. The 

maturation and union of gametes always take place within the


walls formed by the conjugating tube and the two gametangia. 

This conjugation apparatus is relatively persistent and the zygospore 

remains in the enclosure for days or weeks after its own 

walls are mature. Zygospores at first have two nuclei and either 

one set of chromatophores (Spirogyra) derived from the receptive 

gametangium, or two sets (Zygfjema and Mougeotia) derived 

from both gametangia, one of which disintegrates later. After the 

union of the nuclei, reduction division occurs and four nuclei 

result. Of these, three disintegrate and the remaining one becomes 

the nucleus of the basal cell of the sporeling on germination. 

Only when one contemplates the many successive steps in 

conjugation from the development of papillae and adhesion of 

the gametangia onward to the maturation of the spore walls and 

protoplast, does he realize how very complicated are the chemical, 

physical, and biological processes that are integrated in zygospore 

development (PI. I, Figs. 3, 8, 9, and 10). 

Parthenospores may be formed when the normal union of one 

gamete with another fails to occur either by absence of an opposite 

gamete, or by sudden changes in environmental conditions. In 

some collections gametes are numerous; in others, rare. Partheno- 

spores can usually be distinguished from aplanospores by their 

position in the gametangial cells and their relation to adjacent 

zygospores. It is customary to say that "they resemble the zygo- 

spores of the same species but are smaller." Akinetes, aplano- 

spores, zygospores, and parthenospores have all been seen germi- 

nating by numerous students. New filaments grow from any of 

these forms. 

The taxonomy of the Zygnemataceae has been centered on the 

conjugation apparatus: its development, forms, and zygospores. 

The evolutionary history of reproduction in the group, however, 

must have begun with propagation and survival by akinetes. 

These are frequently seen in other families of the Chlorophyta. 

The development of aplanospores must have been a next step in 

evolution. This is not a large step either, since it implies merely 

the contraction of the protoplast and the growth of a spore wall. 

This type of spore also occurs in many other families of the 

Chlorophyta. 

When aplanosporangia became differentiated chemically and 

hormones with plus and minus properties were released which 

brought about local growth of cell walls followed by adhesions


between cells, the first step in conjugation had been taken. Adhesion 

without conjugation occurs in several species of Mougeotia. 

Conjugation is attained when the double wall formed by 

adhesion is dissolved locally by enzyme action. The two proto- 

plasts or gametes are then in direct contact and the conjugating 

apparatus is established. 

Obviously the primitive akinetic or aplanosporic species lacked 

the most characteristic feature of present-day Zygnemataceae until 

the regular union of gametes through openings between adjacent 

gametangia became the most prevalent mode of reproduction. 

From this point of view parthenospores are protoplasts which 

started up the gametic pathway but had their development terminated 

at the level of aplanospores. Since they contain the same 

factors for wall color and patterns, the walls of parthenospores 

resemble those of the aplanospores of the same species. Since 

zygospores also contain these same factors for wall characteristics, 

one would hardly expect them to have other wall structures. One 

would anticipate larger sizes and other forms, since they are the 

product of two protoplasts. From this point of view, one should 

say that the walls of zygospores resemble those of the aplanospores 

rather than the reverse. These surmises concerning the order of 

development of the several reproductive structures seem far more 

plausible than the traditional statements and implications that the 

ancestral form of reproduction was by zygospores, and that the 

parthenospores and aplanospores have eventuated from the conjugation 

apparatus by the loss of factors, enzymes, and hormones. 

Of the 534 species of Zygnemataceae here described i reproduces 

only by akinetes, 38 by aplanospores, 494 by zygospores, and 

I has been found only in a vegetative condition. Of the 494 

zygosporic species, scalariform conjugation occurs in 400 species; 

72 species have both lateral and scalariform conjugation; and 22 

species usually conjugate only laterally. Probably all the species 

propagate by akinetes, and 77 of the zygosporic species also reproduce 

by aplanospores. Most spores are colorless, yellow, or brown. 

Blue spore walls have been found only in the genera: Zygnema 

(30 species), Zynemopsis (i species), Zygogonium (2 species), 

and Mougeotia (8 species). 

In this family only the zygospores may be hybrid in character 

following conjugation between different species. The filaments 

that develop from hybrid zygospores are haploid, meiotic, or


gametic segregates. In the few instances in which such progeny 

have been studied, individual filaments inherit the factor for cell 

diameters, forms of receptive gametangia, zygospore size, form, 

and wall markings independently. They are expressed through 

the cytoplasm of the female gametes. So long as these segregates 

reproduce by cell division, by akinetes, by aplanospores, and by 

conjugation between cells of the same haploid filament, the gene 

complex of the progeny is identical and the filaments are uniform. 

Doubtless many of the "species" that are collected and named are 

taxonomic units, or clones, that have originated in this way. Other 

species seem to have originated by polyploidy and by mutation, 

but the evidence for this statement is purely circumstantial. 

The bases for the separation of the genera are shown in 

the following key. Three genera (Hallasia, Pletirodiscus, and 

Entransia) are tentatively and purposely defined to emphasize 

the need for further study of the development and reproduction 

of these species. All the forms described in this key are designated 

as "species." Many variations have been seen in the collections 

studied but until more is known about hybrid segregates, isolated 

clones, and the effects of the various environmental factors, it 

seems unprofitable to assign "variety" and "form" names to every 

variant. Many alleged "varieties" are not even closely related to 

the species to which they have been assigned. 

Key to the Genera of ZYGNEMATACEAE 

I. Vegetative cells usually with 2 axile chromatophores, which are 

round, radially branched, pillow-shaped, or disclike, with nucleus 

contained in the cytoplasmic bridge between them 

I. Chromatophores usually a pair of axile stellate or globose radi- 

ally symmetric bodies, each with a central pyrenoid 

a) Zygospores compressed-globose or ovoid in the tubes or in 

one of the gametangia; aplanospores cylindric-ovoid occupy- 

ing all or most of the cell; gametangia not filled with a 

dense refractive colloid after conjugation, and without cytoplasmic 

residues i. Zygnema 

b) Zygospores quadrangular-ovoid, or round pillow-shaped, 

formed in the extremely wide but shallow conjugating tubes; 

aplanospores ellipsoid or asymmetrically ovoid; successive 

layers of cellulose and pectic colloids added inside the gam- 

etangial walls during conjugation; similar changes occur in


sporiferous cells during aplanospore formation; no cytoplasmic 

residues 2. Zygnemopsis 

c) Zygospores unknown; 2-7 chromatophores in the cells; 

aplanospores ellipsoid, on germination 1-3 sporelings develop 

from each 3. Hallasia 

2. Chromatophores a pair of ovoid bodies with, or without, irreg- 

ular processes, each containing a pyrenoid; zygospores in spo- 

rangia of 2 cuplike parts with a suture between; aplanospores 

and akinetes the usual method of reproduction; gametangia and 

aplanosporangia contain cytoplasmic residues after conjugation 

and spore formation 4. Zygogonium 

3. Chromatophores a pair of disc-shaped bodies each with a central 

pyrenoid; sporangium wall of 2 cups with an equatorial belt 

between them, otherwise similar to Zygogonium 

5. Pleurodiscus 

II. Vegetative cells, with single axile, platelike chromatophores with- 

out pyrenoids; nucleus attached laterally near middle of the cell 

6. Mougeotiopsis 

III. Vegetative cells with i, rarely 2, axile, flat ribbonlike or plateUke 

chromatophores, with several or many pyrenoids; nucleus attached 

laterally or between the chromatophores when 2 are present 

1. Gametangia similar to the vegetative cells before the beginning 

of conjugation 

a) During conjugation successive layers of pectic and cellulose 

colloids are added to the inside of the gametangial walls, 

filling the lumen; walls of sporangia similarly modified during 

spore formation 7. Debarya 

b) During conjugation as the gametes contract and move toward 

the conjugating tubes granular cytoplasmic residues 

are left in the gametangia 8. Moitgeotia 

2. Gametangia are short specialized cells cut off near the ends of 

long vegetative cells 9. Temnogameturyi 

IV. Vegetative cells with 2 parallel flat chromatophores on opposite 

sides of the cell, each containing several pyrenoids; nucleus central 

in a cytoplasmic pillar between the flat sides of the 2 chromatophores; 

conjugation between reflexed gametangia 

10. Sirocladium 

V. Vegetative cells with i or 2 broad parietal chromatophores on one 

side of the cell, each with several pyrenoids, and laciniate lateral 

margins; in young cells the nucleus is near the middle of the single 

chromatophore, in mature cells in bridge between the 2 chroma- 

tophores; reproduction unknown 11. Entransia

TAXONOMIC CHARACTERISTICS ii 

VI. Vegetative cells with i to i6 parietal, more or less spirally arranged 

ribbonlike chromatophores, each with several or many pyrenoids 

arranged in a single median line; nuclei centrally located and sup- 

ported by cytoplasmic strands; zygospores ellipsoid, ovoid, or lenticular, 

always formed in one of the gametangia 

1. With conjugating tubes formed by one or both gametangia 

before conjugation; outer layer of vegetative cell walls of pectic 

compounds, which usually disappears during conjugation 

12. Spirogyra 

2. Without conjugating tubes, conjugation directly through an 

opening where the reflexed gametangia are in contact; this area 

of contact becomes encircled by a ring of pectic compound; 

vegetative cells without a pectic sheath, chromatophores only 

slightly curved 13, Sirogonium 

Other Summaries of the Zygnemataceae 

Vaucher, J. P. 1803. Conjuguees. Histoire des Conjerves d'eau douce. 

Geneva, pp. 37-81. 

Agardh, C. A. 1824. Systerna Algarum. Lund. 

Hassall, A. H. 1845. History of British Freshwater Algae. London. 

Bary, A. de. 1858. U titersuchungen iiber die Familie der Conjugaten. 

Leipzig. 

Palla, E. 1894. "Ueber eine pyrenoidlose Art und Gattung der Con- 

jugaten." Berichte deutsch. hot. Gesells. 12, p. 228. 

West, G. S. 1916. "Zygnemaceae." Algae. Cambridge Botanical 

Handboohj. i, pp. 331-53. 

Oltmanns, Fr. 1922. "Zygnemaceae." Morphologic der Algen. Jena, i, 

pp. 87-106. 

Skuja, H. 1929. "Siisswasser Algen von den westestnischen Inseln." 

Acta Horti Bot. Univ. Latviensis. 4, pp. 38-49. 

Czurda, V. 1932. Zygnemales. Siisswasserflora Mitteleuropa. 9. 

Smith, G. M. "Zygnemataceae." Freshwater Algae of the United 

States, pp. 536-57. 

Transeau, E. N. 1934. "Genera of the Zygnemataceae." Trans. Amer. 

Micros. Soc. 53, pp. 201-7. 

Fritsch, F. E. 1935. "Zygnemoideae." Structure and Reproduction of 

the Algae, pp. 316-37. 

Czurda, V. 1937. Conjugatae. Handbuch der Pflanzenanatomie. 6. 

Kolkwitz, R., and Krieger, W. 1941-44. Zygnemales. Rabenhorst's 

Kryptogam enflora von Deutschland und der Schweiz. 13, abt. II. 

(Keys to genera and species. Contains most complete bibliography, 

lists of obsolete names, and alleged synonyms.)


TABLE I 

Summary of the OBstRvto 

Usual Methods of Reproduction among the Zygnemataceae

CHAPTER TWO 

THE GENUS ZYGNEMA C. A. AGARDH 1824 

The plants classified as species of Zygnema consist of unbranched 

filaments of short cylindric cells usually covered by a 

pectose sheath. To the field collector they are less slippery than 

the Spirogyras but more slippery than the Mougeotias. There are 

exceptions, of course, because the sheaths vary in thickness from 

those which are barely visible under the microscope to those which 

are thicker than the cells themselves. In regions of low tempera- 

ture and alkaline water, the sheaths are denser and highly stable. 

Similar sheaths are found on filaments living on wet shaded soil 

on pond margins. The thicker sheaths often have visible struc- 

tural lines at right angles to the filaments. 

Zygnemas live as annuals, and may complete their life cycle 

in a few weeks and then disappear. They are most abundant and 

more frequently found reproducing in temporary ponds and 

ditches. In permanent ponds one may find vegetative filaments 

throughout the year. This is not to be construed as evidence that 

individual plants are perennial. It is far more probable that the 

germination of spores and akinetes occurs throughout the year. 

In cold temperate regions the most abundant germination starts 

in autumn and winter, and culminates in early spring. As ponds 

become shaded by the growth of marginal shrubs and trees, reproduction 

decreases and finally ceases entirely, but the Zygnemas 

are perpetuated for a subsequent period of years by the overwin- 

tering of akinetes and fragments of filaments. They survive cold 

and dry periods in the ooze and silt of the pond bottom. During 

the drought period between 1930 and 1935 a small pond near 

Columbus, Ohio, was dry for three and a half years. When the 

rains finally restored the pond, filaments of Zygnema sterile became 

abundant within three weeks. This species reproduces by 

akinetes only. 

Zygnemas have been collected on all the continents from sea 

level to alpine summits, and from the torrid to the frigid zones. 

13

14 

ZYGNEMATACEAE 

In higher latitudes and altitudes the species are not well known 

because they rarely have been found with zygospores. 

In warm regions it is not improbable that some species are 

perennial; that is, some of the filaments form spores and die, 

while others merely break into segments which continue vegeta- 

tive growth. In well-aerated running water the Zygnemas are 

rarely found fruiting, but in the shallow pools adjoining such 

streams one can usually collect the same species in a fruiting 

condition. 

The average length of the filaments of Zygnemas is a few 

inches, much shorter than that of the Spirogyras. Apparently 

before the filaments become very long the pectic sheath breaks 

and the cells separate. Cell diameters vary from 8 to 58 /^ but more 

than half the species have cell diameters between 20 and 30M. 

Usually there are two axial chromatophores in each cell with 

the nucleus contained in the cytoplasmic bridge connecting them. 

Each chromatophore consists of a round body, with irregular short 

branches radiating in all planes, containing a conspicuous central 

pyrenoid. As a result of food accumulation the chromatophores 

may become merely two large globose bodies, or may completely 

fill the lumen of the cell. 

On rare occasions one may find filaments in which each cell 

has two axial chromatophores on either side of the nucleus. In 

three collections that I have examined there were four chroma- 

tophores in the cells of some filaments arranged in the form of 

an X with the nucleus in the center. 

Sexual reproduction occurs in 82 of the 95 described species. 

Twelve others reproduce by aplanospores, and i by akinetes only. 

Of the described species reproducing by zygospores 37 are isogamous, 

with spores in the conjugating tubes; and 45 are anisogamous, 

with spores in one of the gametangia. Of the 95 species, 

70 have scalariform conjugation, 9 both scalariform and lateral 

conjugation, and 3 lateral conjugation; no conjugation has been 

observed in the remaining species. Thirty species have blue 

median spore walls when mature. During development these 

walls change from colorless to yellow, to brown, to blue. As not 

all spores mature at the same time, one may find all these stages 

in a collection. If some of the spores are blue, one may be sure 

that the other spores in the filament are immature. 

Four chromatophores are usually visible in immature zygo-

ZYGNEMA 15 

spores, and in parthenospores and aplanospores only two. In 

general the zygospores are compressed-globose or ovoid. There is 

an equatorial suture often marked by a slight ridge or keel 

(carinate), and in some species there are two lesser ridges on 

either side of the suture and parallel with it. These may not be 

visible in fresh fully distended spores but they become evident 

in dried or plasmolyzed specimens. Usually, the polar, or flatter, 

sides of the spores lie in the plane of the tubes, but there are 

6 species in which the plane of compression is at right angles to 

the axis of the tubes. 

The most abundant and generally distributed of the brown- 

spored isogamous species is Z. pectinatum, of the blue-spored 

isogamous species, Z. synadelphum. Of the anisogamous brown- 

spored species Z. stellintim is both abundant and widely distrib- 

uted; Z. peliosporum is its counterpart among the blue-spored 

species. As might be expected, all these species are highly variable 

in dimensions, and local varieties and forms are apparently common. 

It is not improbable that they have been the mutating forerunners 

of nearly related species found locally wherever the 

Zygnemas have been studied intensively. 

There is no good evidence that the taxonomic characteristics 

of species are changed materially by environmental conditions. 

There are alterations in chromatophores, accumulated foods, and 

thickness of walls due to exposure on soil, restricted photosyn- 

thesis, low temperatures, and mineral deficiencies. Reproductive 

capacity may be decreased or increased by external conditions. 

The mode of reproduction by zygospores or aplanospores, and the 

placement of the zygospores in the tubes, or in one of the gametangia, 

are the results of hereditary rather than environmental 

factors. In any one species the position of the spores, whether in 

the tubes or in the gametangia, does not change from season to 

season (see Fritsch and Rich, New Phytologist, 26 [1927]). 

There are several species in which the spores occur in either the 

gametangia or the tubes—even in the same pair of conjugating 

filaments. 

The identification of a species depends partly upon the dimensions 

of the vegetative cells. Vegetative cell diameters should be 

measured at the partition walls. Most important are the relative 

dimensions of the spores, their form, and the color and ornamen- 

tation of the several layers of the spore walls. Obviously only

i6 ZYGNEMATACEAE 

specimens with mature spore walls can be named with any degree 

of satisfaction. Not infrequently the ornamentation can be determined 

only by crushing and separating the several layers of the 

spore wall. In the matter of dimensions, the student should 

remember that every species is a complex of clones with cells of 

slightly different sizes and proportions. These may be in part 

smaller or larger than the dimensions given in the key. The 

dimensions given in the descriptions of species are either those 

of the original collection, or the dimensions as they may have 

been modified by the study of subsequent collections. How great 

a departure from the original is necessary to warrant the segre- 

gation of a new species cannot be determined by any simple rule. 

Study and restudy of many collections will show that some species 

are only narrowly variable, while others vary within wide limits. 

These remarks are equally applicable to the species of other genera 

of the Zygnemataceae. 

In the descriptions of species the characteristics of the outer 

spore wall are usually omitted since there are only a few species 

in which they are not thin, smooth, colorless, and transparent. 

The median spore wall may be variously colored and ornamented. 

I have tried to distinguish among punctate, scrobiculate, and pit- 

ted according to the size of the pits, and in many instances have 

been able to give the diameters of the pits and the distances between 

them in microns. Errors sometimes occur in descriptions 

and figures where contraction ridges and irregular folds are mis- 

taken for ornamentation. These may be due to contraction of the 

spore contents either by drying or by plasmolysis, and may be 

recognized readily by applying a dilute solution of potassium 

hydroxide. Real structural patterns are enlarged and made more 

distinct by this treatment, while contraction ridges disappear. In 

studying dried specimens it is well first to wet them with water 

on the slide and then to apply a drop of lactic acid, and after that 

to heat the slide until the acid begins to boil. This treatment will 

remove calcium carbonate and clarify both the walls and cell 

contents of most species. Some of the older species were described 

as having smooth median spore walls, although recent study of 

the type specimens has shown them to be punctate. This circum- 

stance is probably explained by the poor resolving power of the 

microscope lenses of the last century as compared with those 

available today.

ZYGNEMA 17 

It may be of historic interest to know that certain species of 

Zygnema have been classified previously in the genera : Globulina 

Link 1820; Tendaridea Bory 1822-31; Stellulina Link 1833; 

Tyndaridea Hassall 1841; Zygogonium Kiitzing 1843; and 

Thwaitesia Montagne 1845. More recently Czurda (1932) has 

included among the Zygnemas certain species which are here 

classified in the genera: Zygogonium, Zygnemopsis, Hallasia, 

and Pleurodiscus. 

Key to Species of ZYGNEMA 

I. With aplanospores, zygospores infrequent or absent 53 

I. With zygospores, sometimes aplanospores also 2 

2. Zygospores wholly or largely in the conjugating tubes. ... 3 

2. Zygospores usually in one of the gametangia 26 

3. Median spore wall colorless, yellow, or brown when mature. 4 

3. Median spore wall blue when mature 17 

4. Zygospores globose to ovoid 5 

4. Zygospores compressed, at right angles to the tubes 22 

5. Diameter vegetative cells less than 20 /u. 6 

5. Diameter vegetative cells usually 20 to 30 /a 8 

5. Diameter vegetative cells usually 30 to 40 /a 15 

5. Diameter vegetative cells more than 40^1 16 

6. Vegetative cells 8-12 /a in diameter, i. Z.oveidanum 

6. Vegetative cells 12-16;^. in diameter 7 

6. Vegetative cells 16-20/x in diameter, 

spores, scrobiculate 4. Z. decussatum 

6. Vegetative cells 16-20 ft in diameter, 

spores, smooth 91. Z. gangeticum 

7. Median spore wall scrobiculate 2. Z. carterae 

7. Median spore wall smooth ^- Z. laevisporum 

8. Median spore wall a single layer 9 

8. Median spore wall of 2 layers 14 

9. Zygospore median wall smooth 23. Z. czurdae 

9. Zygospore median wall scrobiculate, pits less than 4/x 10 

9. Zygospore median wall scrobiculate, pits more than 4 ft 13 

9. Zygospore median wall reticulate 14. Z.pseudopectinatum 

10. Diameter cells 20-21 ix, lateral con- 

jugation through end walls 5. Z. himalayense 

10. Diameter cells 20-30 a*., conjugating tubes of usual form. . 

11 

II. Spores usually less than ju, 40 in diameter 12


II. Spores usually more than 40/1 in diam- 

eter 7. Z. sl{ujae 

12. Spores 24-33 M, scrobiculate, diam- 

eter pits less than 2/i 6. Z. conspicuum 

12. Spores 33-40/1, scrobiculate, diam- 

eter pits 3-4 M ^f. Z. latvtonianum 

12. Spores 38-42/1, punctate and ridged 10. Z.chungii 

12. Spores 36-45/1, scrobiculate, diam- 

eter pits 2/1 13- 2- adpectinattim 

13. Diameter median spore wall pits 5-8/1. u. Z.sinense 

13. Diameter median spore wall pits 4/t. . . 12. Z. globosum 

14. Outer layer wrinkled, inner verru- 

cose 9. Z. verrucosum 

14. Outer layer scrobiculate, inner ver- 

rucose 16. Z. laetevirens 

14. Outer layer pitted, inner verrucose. 15. Z.areolatum 

15. Median spore wall single, pits 2-3/1- in 

diameter 17. Z. pectinatum 

15. Median spore wall single, pits /•• 3-4 in 

diameter 18. Z. excrassum 

15. Median spore wall double, outer ver- 

rucose 9. Z. verrucosum 

16. With median spore wall single. ... 19. Z. neopectinatum 

16. With median spore wall double. . . 20. Z. giganteum 

17. Diameter vegetative cells 16/1 or less. . 21. Z. gedeanum 

17. Diameter vegetative cells 17-27/1. 18 

17. Diameter vegetative cells more than 27/1 21 

18. Median wall smooth 19 

18. Median wall not smooth 20 

19. Median spore wall dark blue, diameter 

34-40/1 22. Z. cyanosporum 

19. Median spore wall light blue, diameter 

30-40 /x 

'î- ^- czurdae 

20. Diameter vegetative cells 16-18/1., 

spores compressed 35- 

20. Diameter vegetative cells 17-24/1.. 24. Z.synadelphum 

20. Diameter vegetative cells 24-26/1, 

•^- carinaturn 

diameter spore 32-35/1 26. Z. coeruleum 

20, Diameter vegetative cells 23-27/1., 

diameter spore 36-42/1 27. Z. goral{hporense 


forming mats on soil 25. Z. terrestre

ZYGNEMA 19 

21. Vegetative cell diameter ^y-Tpii 28. Z. majus 

21. Vegetative cell diameter 32-38 ju. 29, Z. Iîangsiense 

22. Zygospores blue, carinate, and 

punctate 35- 

•^- carinatum 

22. Zygospores yellow to brown 23 

23. Diameter vegetative cells 14-20/i 24 

23. Diameter vegetative cells 20^1 or more 25 

24. Spores 15-25/^ X 25-35 /x, all walls 

smooth 30. Z. raljsii 

24. Spores 28-32 /J. X 36-40//., median 

wall punctate 3i- -^- micropunctatum 

25. Median spore wall smooth, brown 32. Z, momoniense 

25. Median spore wall pitted, yellow-brown 33. Z. circumcarinatum 

25. Median spore wall double, outer layer 

smooth, inner verrucose 34- -^^ pawhus\ae 

SPORES IN THE GAMETANGIA 

26. Median spore wall colorless, yellow, or brown 27 

26. Median spore wall blue 45 

27. Diameter vegetative cells less than 20 /t 28 

27. Diameter vegetative cells 20-30 /i 29 

27. Diameter vegetative cells more than 30 /a 40 

28. Vegetative cell diameter 9-12/^, 

spore wall punctate 36- Z. stagnale 

28. Vegetative cell diameter 14-20 m, 

spore wall punctate 37- 

28. Vegetative cell diameter 15-18 /a, 

-2^- subtile 

spore wall punctate 38- ^- cylindrospermum 

28. Vegetative cell diameter 16-18 ju-, 

spore wall with pits 3-4.5 f. 39- ^- yunnanense 

29. Median spore wall smooth 30 

29. Median spore wall punctate to scrobiculate 31 

29. Median spore wall verrucose 39 

30. Diameter vegetative cells 20-24 /x.. 43. Z.leiospermum 

30. Diameter vegetative cells 26-30 ju,.. 55. Z.insigne 

31. Pits 2/x or less in diameter 32 

31. Pits more than 2 /a in diameter 33 

32. Diameter vegetative cells 22-29^, 

pits widely spaced 46. Z. luteosporum 

32. Diameter vegetative cells 23-26 /x, 

pits closely spaced 48. Z. calosporum


32. Diameter vegetative cells 24-30 /a, 

pits 2 diameters apart 5i- 

^- subcrticiatum 

33. Median wall pits 2-4/' in diameter 34 

33. Median wall pits more than 4 /a in diameter 36 

34. Receptive gametangia nearly cylin- 

dric 49. Z. vaucherii 

34. Receptive gametangia greatly enlarged 

45- '^- substellinum 

34. Receptive gametangia enlarged on conjugating side 35 

35. Diameter vegetative cells 18-24/A 42. Z.tenue 

35. Diameter vegetative cells 24-28 /a 50. Z. normani 

35. Diameter vegetative cells 28-38 /a 59- '^- stellinum 

36. Vegetative cells less than 24 /j. in diameter 37 

36. Vegetative cells more than 24 /a in diameter 38 

37. Diameter median wall pits 4.5-6/^..... 40. Z.extenue 

37. Diameter median wall pits 7-9 /^ 44. Z. hausmannii 

38. Receptive gametangia inflated in- 

ner side 51. Z. insignisporum 

38. Receptive gametangia globosely in- 

flated 54. Z. germanicum 

38. Receptive gametangia nearly cylin- 

dric 56. Z. janicum 

38. Receptive gametangia enlarged ... 57. Z. subfanicum 

39. Median spore wall verrucose 52. Z. vaginatum 

39. Median spore wall with raised prominences 

41. Z. tholosporum 

39. Median spore wall double, inner layer 

verrucose 47- 

-^^ flavum 

40. Diameter vegetative cells 30-40;^ 41 

40. Diameter vegetative cells 40-50 /a. . 65. Z.neocruciatum 

40. Diameter vegetative cells 50-60 ju.. . 66. Z.crassitisculum 

41. Median spore wall scrobiculate or pitted 42 

41. Median spore wall verrucose and wavy 62. Z.bohemicum 

41. Median spore wall of 2 layers, inner 

reticulate -verrucose, outer thick, 

smooth 6t,. Z. mirandum 

42. Median wall with pits less than 4/^ in diameter 43 

42. Median wall with pits more than 4/x in diameter 44 

43. Spores usually globose, diameter pits 

3-4M 59. Z. stellinum

ZYGNEMA 21 

43, Spores usually globose, diameter pits 

1-2 /A 60. Z. cruciatum 

43. Spores cylindric-ovoid, diameter pits 

i-2ju. 61. Z. cylindrosporum 

44. Diameter pits on median wall 

2-6.5 >^ 92. Z. \wangtungense 

44. Diameter pits on median wall 4-5 A^ 64. Z. inconspicuum 

44. Diameter pits on median wall 

7-12 ft 58. Z. transeauianum 

45. Receptive gametangia cylindric or slightly enlarged 46 

45. Receptive gametangia much enlarged or inflated 49 

46. Diameter vegetative cells average less than 27 /x 

46. Diameter vegetative cells average more than 27 /x 48 

47. Median spore wall with scattered punctations 

90. Z. mucigenum 

47. Median spore wall smooth 68. Z. chalybeospermum 

47. Median spore wall punctate 71. Z. melanosporum 

47. Median spore wall scrobiculate and 

carinate 72. Z. excompressum 

48. Median spore wall smooth 69. Z. cyaneum 

48. Median spore wall densely punctate 

74. Z. azureum 

48. Median spore wall scrobiculate 79. Z. catenatum 

48. Median spore wall pitted 77- ^- ornatum 

49. Diameter vegetative cells less than 20 /x 50 

49. Diameter vegetative cells 20-30/^ 51 

49. Diameter vegetative cells more than 30 /x 52 

50. Vegetative cells 14-17 ft in diameter 67. Z.atrocoeruleum 

50. Vegetative cells 18-24/u, in diameter 70. Z.collinsianum 

51. Median spore wall with pits 1-2 /a in 

diameter 73- '^- peliosporum 

51. Median spore wall with pits 3-4 /^ in 

diameter 15- ^' carinthiacum 

51. Median spore wall with pits 4-5/^ in 

diameter 70. Z. collinsianum 

51. Median spore wall with pits 7-11/^ in 

diameter 76. Z. pawneanum 

52. Pits o£ median wall about 6fi in 

diameter 17- ^- ornatum 

22 

ZYGNEMATACEAE 

REPRODUCTION BY APLANOSPORES 

53. Aplanospores blue 54 

53. Aplanospores or akinetes yellow to brown 55 

54. Spores punctate with irregular elongate 

pits (S7. Z. borzae 

54. Spores scrobiculate, diameter vege- 

tative cells 21-23 M 80. Z. jrigidum 

54. Spores scrobiculate, diameter vege- 

tative cells 33M 85. Z. hypnosporum 

54. Spores smooth 84. Z. quadrangitlatum 

55. Diameter vegetative cells less than 25 /a 56 

55, Diameter vegetative cells 26 to 36 /i. 57 

55. Diameter vegetative cells greater than 36 ^ 58 

56. Vegetative cell diameter 1 5-1 8 m, 

spores dolioform 94. Z. mlrificum 

56. Vegetative cell diameter 16-21 /i., 

spores ovoid 81. Z. spontanettm 

56. Vegetative cell diameter 17-20M, 

spores cylindric 86. Z. schwabei 

56. Vegetative cell diameter 20-22 ft, 

spores ellipsoid 93- 

-^- ellipsoideum 

57. Median spore wall scrobiculate 82. Z.cylindricum 

57. Median spore wall granulose 88. Z. subcylindricum 

57, Median spore wall pitted 95- ^- khannae 


spore cylindric 89. Z. irregulare 

58. Diameter vegetative cells 44-54 m, 

akinetes 83. Z. sterile 

The following species have been found in some collections producing 

both zygospores and aplanospores: Z. catenatum, Z. circumcarinatum, 

Z. collinsiantim, Z. cruciatum, Z. excrassttm, Z. jantcum, 

Z. giganteum, Z. insigne, Z. leiospermum, Z. neocru datum, Z. pectinatum, 

Z. peliosporum, Z. stellinum, Z. terrestre, and Z. synadelphum. 

Descriptions of Species 

I. Zygnema oveidanum Transcau 1934. Trans. Amer. Micros. 

Soc. 53, p. 208, PI. 17, Fig. I. 

Vegetative cells 8-12 ^ x (32-) 35-40 (-68) m; conjugation scalariform; 

zygospores formed in the conjugating tubes, ovoid to globose, 12-15/1 x 

15-30 ju; median spore wall colorless to yellow, punctate; pits about lu 

in diameter. (PI. II, Fig. 3.)

ZYGNEMA 23 

United States: Florida, Oveida Springs, and Fort Myers; Louisiana, 

Alexandria. 

2. Zygnema carterae Czurda 1932. Siisswasserfiora Mitteleuropa. 

9, p. 1 14. Carter. ]our. Linn. Soc. of London Bot. 46, p. 62. 

Vegetative cells 13-16^ in diameter; conjugation lateral or scalari- 

form; zygospores formed in the conjugating tubes, globose, 30-35 /a; 

median spore wall brown, scrobiculate. 

New Caledonia (Carter). 

3. Zygnema laevisporum Jao 1935. Trans. Amer. Micros. Soc. 

54, p. 56, PI. I, Figs. 7-8. 

Vegetative cells 13-16/x x (48-)64-i28m; chromatophores usually 2, 

sometimes 3 or 4, occupying the middle of the cell; conjugation usually 

lateral, rarely scalariform; zygospores compressed-globose, formed in 

the conjugating tubes, 35-42 ju x 32-35 a

24 

ZYGNEMATACEAE 

spores formed in the conjugating tubes, globose to ovoid, 24-32 /^ x 

26-33 /a; median spore wall brown, scrobiculate; pits about 1.5-2.0/^ 

in diameter and the same distance apart. (PI. II, Fig. 8.) 

United States: Illinois; Wisconsin; Oklahoma; Kentucky. 

England; Germany; Austria; Belgium; Bulgaria; Russia. 

7. Zygnema skujae Czurda 1932. Siisswasserfiora Mttteleuropa. 

9, p. 109. Skuja. Acta Horti Bot. Ufiiv. Latviensis. 4, p. 40. 

1929. 

Vegetative cells 20-27 jm -^ 40-1 00 /j.; conjugation scalariform; gam- 

etangia slightly bent; zygospores formed in the conjugating tubes, 

globose to ovoid, 40-55/^; median spore wall olive-brown, coarsely and 

thickly scrobiculate. 

Latvia. 

8. Zygnema lawtonianum Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 209, PI. 17, Fig. 5. 

Vegetative cells 23-27 /x x 23-99 m; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, globose to ovoid-globose with 

a distinct equatorial suture, 33-40 /x x 3^-46^^; outer spore wall united 

with the tube wall; median spore wall brown, coarsely scrobiculate; 

pits 3-4 M in diameter and about the same distance apart. Spores are 

cut off from the gametangia by a distinct cross wall. (PI. II, Fig. 9.) 

United States: Oklahoma, Medicine Park, April 29, 1932. 

Burma (Skuja). 

9. Zygnema verrucosum Jao 1935. Sinetisia. 6, p. 566, Pi. i, 

Figs. 3-4. 

Vegetative cells 24-26 m x 29-48 /a; conjugation scalariform; zygospores 

formed in the conjugating tubes, subglobose to ovoid, 32-37 m x 

38-55 /x; outer spore wall smooth, hyaline; median wall of 2 layers, of 

which the outer is yellow and irregularly wrinkled, the inner, yellowbrown 

and densely granulate to verrucose. (PI. II, Figs. lo-ii.) 

China, Szechwan. 

Differs from Z. pawhuskfie Taft in the larger vegetative cells, the 

absence of a distinct suture on the spore, and the absence of compressed- 

ovoid spores. 

10. Zygnema chungii Li 1934. Trans. Amer. Micros. Soc. 53, 

p. 213, PI. 18, Fig. 15. 

Vegetative cells 24-28/-1 x 58-72iM; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, globose to ovoid, 38-42/i x 

38-47 /x; outer wall colorless, smooth; median spore wall yellow-brown,

ZYGNEMA 25 

thick, punctate, and markeci by an irregular network of ridges; pits 

about iM in diameter, 3-6 /a apart. (Pi. II, Fig. 12.) 

China, Hupeh, Wuchang (H. H. Chung Coll.). 

11. Zygnema sinense Jao 1935. Sinensia. 6, p. 567, PI. i, Fig. 5. 

Vegetative cells /i. 25-27 x 25-48 /i.; conjugation scalariform; spores 

formed in the enlarged tubes, extending slightly into the gametangia; 

zygospores subglobose to ovoid, not compressed, 35-42 /x x 40-48 /a; 

median spore wall brown, pitted; pits 5-8 ^ in diameter, 3-9 /x apart. 

(PI. Ill, Fig. I.) 


Differs from Z. lawtonianum Taft in larger zygospores, larger pits, and 

absence of distinct suture; from Z. areolatum Transeau in having a single 

median spore wall, larger pits, and smaller vegetative cells. 

12. Zygnema globosum Czurda 1932. Susswasserfiora Mitteleuropa. 

9, p. 109, Fig. no. 

Vegetative cells 26-28^11 x ju.; 70-95 conjugation scalariform; zygospores 

formed in the conjugating tubes, globose or ovoid, 45-50 m x 

50-65 /x; median spore wall brown, thick, pitted; pits about 3/^^ in diam- 

eter according to the figure. (PI. Ill, Figs. 2-3.) 

Bohemia; Central India. 

13. Zygnema adpectinatum Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 209, PI. 17, Fig. 6. 

Vegetative cells 25-30 /^ x 30-1 00 ju,; conjugation scalariform; zygospores 

formed in the conjugating tubes, ovoid to globose, 36-40 /x x 

40-50 /a; median spore wall yellow-brown, scrobiculate; pits 2/^ in diam- 

eter. (PI. Ill, Fig. 4.) 

United States: Illinois. 

14. Zygnema pseudopectinatum Czurda 1932. Susswasserfiora 

Mitteleuropa. 9, p. 115, Fig. 117. Fritsch and Stephens. 

Trans. Roy. Soc. S. Africa. 9, p. 53. 1921. 

Vegetative cells 27-30 /a x 50-74 /a; conjugation scalariform and 

lateral; zygospores formed in the conjugating tubes, globose to ovoid, 

33-36 /x X 40M; median spore wall brown, thick, reticulate. 

South Africa, Transkei. 

15. Zygnema areolatum Taft & Transeau 1934. Trans. Amer. 

Micros. Soc. 53, p. 210, PI. 17, Fig. 8. 

Vegetative cells 27-30 m x 46-66 /x; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, globose to ovoid, 32-46^ x 

33-50 ju; median spore wall brown, of 2 layers, of which the outer is


pitted; pits 5-6 /i in diameter, 1.5-3M apart, the inner layer densely and 

minutely verrucose. (PI. Ill, Fig. 5.) 

United States: Oklahoma. 

16. Zygnema laetevirens Klebs 1886. Untersuch. Bot. Inst. 

Tubitigen. 2, p. 333, PI. 3, Fig. 14. 

Vegetative cells 27-34^1 x 40-90 /x; conjugation scalariform; zygospores 

formed in the conjugating tubes, globose, 40-55 ^ in diameter, 

or ovoid, 34-41/4 x 54-68 /a; median spore wall chestnut brown, of 2 

layers, of which the inner is finely verrucose, the outer scattered-scrobic- 

ulate. It is probable that the ornamentation of the inner median wall 

arises from granules formed between the 2 layers. The same may be 

true of Numbers 9 and 15. 

United States: Indiana; Ohio; Mississippi; Alabama. 

Europe; Australia; China (L. C. Li Coll.). 

Spores may be yellow before the verrucose markings of the inner 

median wall appear. The Indiana specimens contained many parthenosporcs 

similar to the zygospores but smaller. 

17. Zygnema pectinatum (Vaucher) Agardh 18 17. Synopsis 

Algarum, p. 102. 

Vegetative cells 30-36 yu, x 25-120 a^; conjugation scalariform, rarely 

lateral; zygospores formed in the conjugating tubes, globose to ovoid, 

35-44)". x ju.; 40-54 median spore wall brown, scrobiculate; pits about 

2-7, li. in diameter; aplanospores ovoid or cylindric, 30-38 /", x ^0-60 ix; 

walls similar. (PI. Ill, Fig. 6.) 

United States: Generally distributed eastward from Minnesota, Ne- 

braska, Oklahoma, and Louisiana. 

Widely distributed in Europe, Asia, Africa, and South America. 

18. Zygnema excrassum Transeau 1934. Tratis. Amer. Micros. 

Soc. 53, p. 209, PI. 17, Fig. 14. 

Vegetative cells 32-36 ^ x 32-80 a^; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, usually ovoid, rarely globose 

(40-) 50-60 )Lt X 50-7o(-8o)/a; median spore wall brown, scrobiculate; 

pits 3-4 M in diameter and about the same distance apart; aplanospores 

cylindric-ovoid, nearly filling the sporogcnous cells. (PI. Ill, Fig. 7.) 

United States: Oklahoma; Illinois; Iowa; Mississippi; Alabama. 

19. Zygnema neopectinatum Transeau 1934. Trans. Amer. 

Micros. Soc. 53, p. 209, PI. 17, Fig. 7, 

Vegetative cells 40-45 /m x 40-85^1; conjugation scalariform; zygospores 

formed in the conjugating tubes, ovoid to globose, 45-54 M x

ZYGNEMA 27 

55-60 /a; median spore wall brown, scrobicialate; pits about 3/^ in diam- 

eter. (PI. Ill, Fig. 8.) 


20. Zygnema giganteum Randhawa 1936. Proc. Indian Acad. Sci. 

4, p. 241. 

Vegetative cells 40-48 /a x 56-90 /a; reproduction by zygospores and 

aplanospores; conjugation scalariform; zygospores formed in the con- 

jugating tubes; zygospores ovoid to globose, 48-64 /^ x 56-70 /a; median 

wall yellow-brown, of 2 layers, of which the outer is undulate pitted and 

the inner smooth or granulate. The other 2 walls are transparent. 

Aplanospores cylindric, filling the cells, with walls similar to those of 

the zygospores, 38-48 /a x ju-. 45-72 (PI. Ill, Figs. 9-10.) 

India, Kapurthala State, Punjab, March, 193 1. 

This description is modified from the original on the basis of specimens 

kindly sent by Mr. Randhawa. Associated with this species in the original 

collection is an anisogamous species with very peculiar conjugating tubes, in 

that a ring of pectic material surrounds the tube at the point of union. This 

is indicated by Randhawa's figures. However, there are no ripe spores in 

the material that I have seen and because of the smaller zygospores I believe 

it is a distinct and unnamed species. 

21. Zygnema gedeanum Czurda 1932. Susswasserfiora Mittel- 

europa. 9, p. 115, Fig. 118. 

Vegetative cells 13-15 jâ x 32-34 ;u; conjugation lateral; zygospores 

formed in the conjugating tubes, ovoid, 22-24 /a ^ 3P~?P-l^''> median spore 

wall blue to blue-black, thick, pitted; pits about im in diameter. (PI. Ill, 

Figs. 11-12.) 

Java. 

22. Zygnema cyanosporum Cleve 1868. Nova Acta Reg. Soc. Sci. 

Upsali. 6, p. 28, PI. 8, Figs. 6-8. 

Vegetative cells about 20-22/1. x 40-180/t; conjugation scalariform; 

zygospores formed in the conjugating tubes, globose, rarely quadrate- 

globose, 30-40 ju. in diameter; median spore wall blue, thick, smooth. 

United States: Michigan. 

Greenland; Sweden; Finland; India; South Africa. 

23. Zygnema czurdae Randhawa 1936. Proc. Indian Acad. Sci. 

4, p. 239. 

Vegetative cells 20-27 /a ^ 30-100/1, with 2 chromatophores; conjugation 

lateral and scalariform; spores formed in the tubes; during 

lateral conjugation the intergametangial wall sphts and the gametangia 

are connected only by the enlarged tubes; in scalariform conjugation the


spores are formed in the tubes; zygospores globose, 30-40 /x in diameter, 

all walls smooth and light blue in color. (PI. Ill, Figs. 13-14.) 

India, Punjab, February, 1931. 

These spores may not be mature and the color may be due to refraction 

of light rather than the presence of a blue pigment. 

24. Zygnema synadelphum Skuja 1926. Acta Horti Bot. Univ. 

Latviensis. 1, p. no, PI. i, Fig. 2. 

Vegetative cells ly-iiiJ. x 34-120 ai; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, ovoid to spheroid, 27-36 m x 

34-44 At; median spore wall blue, of 3 layers, of which the outer is irregularly 

punctate; pits about 1-2 ft in diameter; suture sometimes prominent, 

usually not. Aplanospores cyHndric-ovoid, filling the vegetative 

cells, otherwise similar to the zygospores. (PI. IV, Figs. 1-2.) 

United States: Oklahoma; Texas; Michigan; Ohio; Louisiana; Florida. 

Latvia; China; Africa, Burma. 

In a collection from Alexandria, Louisiana, aplanospores were very 

abundant. In a collection from Florida most of the spores were in the tubes, 

but occasional spores were in the gametangia of both conjugating filaments. 

25. Zygnema terrestre Randhawa 1938. Proc. hidian Acad. Sci. 

8, p. 147, Fig. 29. 

Vegetative cells 18-24^1 x 36-60^1; conjugation scalariform, zygo- 

spores in the tubes or extending into the gametangia, subglobose to 

ovoid, 28-38 /A x 36-54 /x; median wall blue when mature, brownish when 

immature, punctate with pits .5-1 /x in diameter 3-5 m apart; aplan- 

ospores ovoid to dolioform, formed in the enlarged middle part of the 

cells; the outer wall of the cell adjoining the spore changes to pectic 

compound forming a collar. When mature the aplanospore walls are 

similar to those of the zygospores. Aplanospores are 30-34 m x 36-65/1. 

Some filaments have several of the lowermost cells with disintegrating 

chromatophores beneath the soil surface. (PI. VII, Figs. 16-18.) 

India, Fyzabad, forming a light green felt on the soil surface of fallow 

fields at the close of the rainy season, late September and October, 1937. 

26. Zygnema coeruleum Czurda 1932. Siisswasserfiora Mittel- 

europa. 9, p. 107, Fig. 107. 

Vegetative cells 24-26/1 x 40-55/1 in diameter; conjugation scalar- 

iform; zygospores formed in the conjugating tubes, ovoid to globose, 

32/1 x 32-35/1; median spore wall blue, thick, scrobiculate; pits 1.5/1 in 

diameter, 2 diameters apart. (PI. IV, Figs. 3-4.) 

Bohemia; South Africa; northern India.

ZYGNEMA 29 

27. Zygnema gorAkhporense Singh 1938. ]our. Indian Bot. Soc. 

17, p. 370. 

Vegetative cells ^^-^yii x 66-83;".; conjugation scalariform; zygo- 

spores formed in the tubes and extending into the gametangia; zygo- 

spores ovoid to globose, 30-36 /a x 36-43/1; median wall blue, scrobic- 

ulate; pits about 4/* in diameter and 1-31". apart. 

India, Gorakhpur, October 8, 1936. 

28. Zygnema ma jus Czurda 1932. Siisswasserftora Mitteleuropa. 

9, p. 106. Fritsch & Rich. Trans. Roy. Soc. S. Africa, 9, 

p. 56. 1921. 

Vegetative cells 27-30/1. x 27-90 /a; conjugation scalariform; zygospores 

formed in the conjugating tubes, globose to ovoid, /a 33-48 x 

42-50 /a; median spore wall blue, smooth. 

Africa, Transkei Territory. 

29. Zygnema kiangsiense Li 1938. Bull. Fan Mem. Inst. Biol. 

8, p. 94. 

Vegetative cells 32-38 /a x 36-50 /a; conjugation scalariform; zygospores 

formed in the conjugating tubes, ovoid to subglobose, 36-46 /a x 

44-58 /a; median spore wall blue, coarsely scrobiculate; pits 3-5 /^ in 

diameter, 4-7 /a apart. (PI. IV, Fig. 5.) 

China, Kiangsi. 

30. Zygnema ralfsii (Flassall) de Bary 1858. Untersuchungen 

Uber die Familie der Conjugaten, p. 77. 

Vegetative cells 14-20 /a x 38-80 /j^; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, 15-25 /a x 25-35 /a; median spore 

wall brown, smooth. (PL IV, Fig. 6.) 

United States: Pennsylvania, Harrisburg (Wolle). 

British Isles and continental Europe. 

31. Zygnema micropunctatum Transeau 1934. Trans. Amer. 

Micros. Soc. 53, p. 210, PL 17, Fig. 13. 

Vegetative cells i4-i6a

30 

ZYGNEMATACEAE 

spores formed in the conjugating tubes, compressed-globose, with the 

longer diameter at right angles to the conjugating tubes; 25-27/^ x 

30-33A1; median spore wall [?] brown, smooth. 

Ireland. 

33. Zygnema circumcarinatum Czurda 1930. Beih. Bot. Zen- 

tralbl. 47, p. 53, Fig. 15. 

Vegetative cells 20-22/11 in diameter; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, globose or compressed-globose, 

24M to 29A1 in diameter; median spore wall golden-brown, thick, scrobiculate, 

with pits 2-2.5 m '" diameter and 1-2/^ apart; spore wall more 

or less carinate. As the spores mature the tube walls change to pectic 

compounds and form persistent colloidal walls as thick as the spores 

themselves. This often results in separation of the spores from their 

subtending gametangia. Aplanospores similar but smaller, often 

maturing outside the sporogenous cell. (PI. IV, Figs. 8-9.) 

United States: Texas, Eden, April 13, 1938 (Taft Coll.). 

Bohemia. 

In Handbuch der Pflanzenanatomie (6, Conjugatae) Czurda discusses 

and figures stages in conjugation, and germination of spores of this species, 

which he had cultivated. 

Exactly similar stages in spore maturation occur in several species of 

Mougeotia (PI. XVII). Note that the spores are also of the compressed type. 

34. Zygnema pawhuskae Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 209, PI. 21, Fig. 61. 

Vegetative cells 21-24/'. ^ 40-60 /x; conjugation scalariform; zygo- 

spores formed in the conjugating tubes, ovoid to compressed-globose, 

extending into the gametangia, 34-48 /x x 46-65/1; median spore wall 

seal-brown, of 2 layers, the outer smooth with a distinct equatorial 

suture, the inner densely and minutely verrucose, sometimes reticulateverrucose. 

During the early stages of conjugation the outer sporangium 

wall is a pectic layer 3-6 /i in thickness. (PI. IV, Fig. 10.) 


35. Zygnema carinatum Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 210, PI. 17, Fig. 9. 

Vegetative cells 16-18/1 x 33-36 /

ZYGNEMA 31 

7^^. Zygnema stagnale (Hassall) Kiitzing 1849. Species Algarum, 

p. 444. 

Vegetative cells 9-12/^1 x 20-50 m; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia enlarged on the 

inner side; zygospores globose to subglobose, 14-18 /a x 14-20/x; median 

spore wall brown, punctate. 

United States: Massachusetts, North Eastham (Collins Coll.). 

England. 

37. Zygnema subtile Kiitzing 1849. Species Algarum, p. 444. 

Vegetative cells 14-20/x x 30-85 /x; conjugation scalariform or very 

rarely lateral; zygospores in one of the gametangia; receptive gametangia 

greatly enlarged or inflated on the inner side; zygospores ovoid 

to subglobose, 20-29 m x 22-30 m; median spore wall brown, punctate. 


Finland; Germany; Bohemia. 

This is possibly the species figured by G. S. West (1909) as Z. spontaneum 

from Yan Yean Reservoir, Australia. In a collection from Calhoun, 

Illinois, in a filament of 35 cells there were 1 1 gametangia with scalariform 

conjugation, 2 pairs conjugating laterally, 

among them. 

and 20 vegetative cells scattered 

38. Zygnema cylindrospermum (W. & G. S. West) Krieger 1941. 

Zygnemales. Rabenhorst's Kryptogamen flora. 13, p. 260. 

Vegetative cells 15-18)". in diameter; conjugation scalariform; zygo- 

spores formed in one of the gametangia; receptive gametangia cylindric 

or slightly enlarged; zygospores ovoid, itx 15-19 x 23-54 /x; rnedian spore 

wall brown, punctate. (PI. IV, Fig. 16.) 

Shedands (Loch Asta); Wales (Wittrock and Nordstedt No. 750); 

Cape Colony (Stephens Coll.). 

39. Zygnema yunnanense Li 1940. Bull. Fan Mem. Inst. Biol. 

10, p. 63. 

Vegetative cells 16-18 ju, x 50-1 /x; 04 conjugation lateral; receptive 

gametangia more or less enlarged; zygospores globose to ovoid, 32-40 /x 

X 38-48 A^; median wall thick, deeply scrobiculate, with pits 3-4.5 /^ in 

diameter, 2-3 /x apart, yellow at maturity. 

China, Yunnan, October i, 1938. 

40. Zygnema extenue Jao 1935. Sinensia. 6, p. 568, PL i, Fig. 8. 

Vegetative cells 19-25 /x x 32-48^1,; conjugation scalariform and 

sometimes lateral; receptive gametangia more or less enlarged; zygo- 

spores subglobose to ovoid, 23-32 /x x 26-39 /x; median spore wall scro-

32 

ZYGNEMATACEAE 

biculate; pits 4.5-6.5/1 in diameter and fi 2-7, apart, yellow-brown at 

maturity. (PI. TV, Fig. 12.) 


41. Zygnema tholosporum Magnus & Wille 1884. Sydamerica 

Algflora, p. 33, Pi. I, Figs. 49-52. 

Vegetative cells 20 /x x 20-40//.; conjugation scalariform; zygospores 

in one of the gametangia; receptive gametangia inflated; zygospores 

globose, 36 /i in diameter; median spore wall brown, with numerous 

circular prominences (umbonate). (PI. IV, Fig. 13.) 

Uruguay, Montevideo. 

42. Zygnema tenue Kiitzing 1849. Species Algarum, p. 445. 

Vegetative cells 18-24 /t x 20-70 ju-; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia greatly enlarged 

or inflated toward the middle; zygospores globose to ovoid, often somewhat 

compressed, 25-30 /x x 25-40 as median spore wall brown, scrobic- 

ulate; pits 2-3/A in diameter, 3-4/i. apart. (PI. IV, Figs. 14-15.) 

United States: Illinois; Oklahoma. 

Europe, widely reported; North and South Africa; China; Ceylon. 

43. Zygnema leiospermum de Bary 1858. Untersuchungen iiber 

die Familie der Conjugaten, p. 77, PL i, Figs. 7-14. 

Vegetative cells 20-24/1 x 20-40/1; conjugation scalariform; zygo- 

spores in one of the greatly enlarged or inflated gametangia; zygospores 

globose to ovoid, 2^-30/1 x 23-32 /t; median spore wall brown, smooth; 

aplanospores similar, but smaller in diameter. 

United States: Minnesota and Illinois to the east coast. 

Greenland; Iceland; British Isles; continental Europe. 

44. Zygnema hausmannii (De Notaris) Czurda 1932. Siisswasser- 

flora Mitteleuropa. 9, p. 121, Fig. 125. 


spores in one of the gametangia; receptive gametangia enlarged mostly 

on the inner side; zygospores globose or slightly compressed, 32-34/t x 

28-34/1; median spore wall yellow-brown, pitted; pits 7-9/1 in diam- 

eter; equatorial suture distinct. (PI. IV, Figs. 17-18.) 

Austria; northern Italy; southern Australia. 

45. Zygnema substellinum Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 212, PI, 17, Fig. 10. 


spores in one of the gametangia; receptive gametangia greatly enlarged, 

becoming nearly globose; zygospores globose, filling or nearly filling

ZYGNEMA 33 

the gametangia, 42-46 ,«, in diameter; median spore wall yellow-brown, 

scrobiculate; pits 3/"- in diameter. (PI. V, Fig. i.) 

United States: Oklahoma, Bartlesville, April 25, 1932. 

This species is remarkable for the large size of the zygospores as com- 

pared with the size of the vegetative cells. 

46. Zygnema luteosporum Czurda 1932. Siisswasserflora Mitteleuropa. 

9, p. 122, Fig. 225. 

Vegetative cells 22-24/^1 x 45-80 /x; conjugation scalariform; zygospores 

in one of the gametangia; receptive gametangia cylindric or 

slightly enlarged; zygospores ovoid, 26^ x 38 /a; median spore wall 

yellow, thick, scrobiculate, with pits widely spaced. (PI. V, Fig. 2.) 

Bohemia. 

47. Zygnema flavum Taft 1946. Trans. Amer. Micros. Soc. 65, 

p. 24. 

Vegetative cells 22-27 /a x 48-68 a^; conjugation scalariform; zygo- 

spores formed in one of the gametangia; receptive gametangia cyhndric 

or slightly enlarged; zygospores cylindric-ovoid to ovoid, 24-29 m x 

35-51 fi; outer spore wall thin and smooth; median spore wall of 2 

layers, the outer thick and smooth, the inner irregularly verrucose; both 

layers light yellow; innermost spore wall thin, smooth. (PI. V, Fig. 3.) 

United States: Texas, Eden, April 13, 1938. In this collection some of 

the vegetative cells contained 4 chromatophores. 

48. Zygnema calosporum Jao 1935. Sinensia. 6, p. 568, Pi. i. 

Fig. 7. 

Vegetative cells 23-26 ju x 16-48 /x; conjugation scalariform; recep- 

tive gametangia shortened and greatly enlarged; zygospores globose to 

subglobose, 29-35 m ^ 32-35 m; median spore wall densely scrobiculate; 

pits 1.5-2.5 M^ in diameter, 1-1.5/'. apart, yellowish-brown at maturity. 

(PI. V, Fig. 4.) 


Differs from Z. substellinum Taft in greater diameter of the vegetative 

cells and smaller spores; from Z. vaucherii in shorter vegetative and repro- 

ductive cells, and in denser scrobiculations of the median spore wall. 

49. Zygnema vaucherii Agardh 1824. Systema Algarum, p. 77. 

Vegetative cells 24-28 a"- x 50-180^1; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia gradually or 

abruptly inflated toward the middle; zygospores ovoid, 24-36 ju. x 26-45 /x; 

median spore wall brown, scrobiculate; pits 2-3 /x in diameter. (PI. V, 

Fig- 5-)

34 

ZYGNEMATACEAE 

United States: Illinois; Indiana; Ohio; Massachusetts. 

Widely reported from Europe. 

50. Zygnema normani Taft 1934. Trans. Amer. Micros. Soc. 53, 

p. 213, PI. 17, Fig. 12. 

Vegetative cells 24-28 /^ x 30-73 /x; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia greatly inflated 

on the conjugating side; zygospores globose or subglobose, 36-46 /a x 

35-45 /n; median spore wall yellow-brown, scrobiculate; pits 3-4 M in 

diameter, 2.5-4 /t apart. (PL V, Fig. 6.) 


India. 

51. Zygnema insignisporum Couch 1944. Ohio Jour. Set. 44, 

p. 277. 

Vegetative cells 24-28/A x 39-71 m; conjugation scalariform; recep- 

tive gametangia inflated on the conjugating side; zygospores globose to 

ovoid, 32-35 /A x 32-35 /a; outer wall of 2 colorless layers, of which the 

outermost is smooth, the inner scrobiculate, with pits 4-5 /^ in diameter 

and about 7/A apart; median wall punctate, yellow. 

United States: Arkansas. 

52. Zygnema vaginatum Klebs 1886. Untersuch. Bot. Inst. Tu- 

bingen. 2, p. 135, PL 3, Fig. 13. Notarisia. 1, pp. 340-41. 

1886. 

Vegetative cells 25-27^1 x 37-75/^; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia slightly en- 

larged; zygospores globose to ovoid, diameter about 28^1; median spore 

wall brown, verrucose-tuberculate. 

Germany; Austria. 

Czurda (1932) and Krieger (1941) described this species as having 

scrobiculate median spore walls. No reason for the change from the 

original description is given. 

53. Zygnema subcruciatum Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 212. 

Vegetative cells 24-30/M x 26-60M; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia cylindric or 

enlarged, mostly on the inner side; zygospores globose to ovoid, 25-32^ 

X 28-40M; median spore wall brown, finely scrobiculate. (PL V, Fig. 7.) 

United States: Oklahoma; Texas; Arkansas; Louisiana; Illinois; Ohio. 

France; Norway; Sweden; China.

ZYGNEMA 35 

54. Zygnema germanicum Czurda 1932. Susswasserflora Mitteleuropa. 

9, p. 125, Fig. 129. 

Vegetative cells 26-28 /^ x 30-36 /j.; conjugation scalariform; zygo- 


or inflated; zygospores globose or compressed-globose, 36-38 /a x 36-45^; 

median spore wall brown, thick, pitted; pits 6-7 ju, in diameter. (PI. V, 

Figs. 8-9.) 

Germany; Czechoslovakia. 

55. Zygnema insigne (Hassall) Kiitzing 1849. Species Algarum, 

p. 444. 

Vegetative cells 26-32 /x x 26-60 ju; conjugation scalariform or lat- 

eral; zygospores in one of the gametangia; receptive gametangia cyUn- 

dric or enlarged; zygospores globose or subglobose, 27-33 /x ^ 27~35/^5 

median spore wall yellow-brown, smooth; aplanospores 28-33 /x, ovoid 

to cyUndric-ovoid, otherwise similar. (PI. V, Figs. 10-12.) 

United States: California to Massachusetts and New Jersey. 

Widely reported from Europe, Australia, South America, and China. 

Many of the records of this species are based on specimens with immature, 

colorless spores. These specimens should not have been named. 

56. Zygnema fanicum Li 1934. Trans. Amer. Micros. Soc. 53, 

p. 212, PI. 18, Figs. 17-19. 

Vegetative cells 28-33 /x x 28-80 /x; conjugation usually scalariform, 

sometimes lateral; zygospores in one of the gametangia; receptive gametangia 

cylindric or enlarged; zygospores globose to ovoid, 30-36 /x x 

34-42 /a; median spore wall yellow, sharply pitted; pits 4-7 /^ in diameter, 

2-3 /x apart, each with a distinct, raised margin; aplanospores 

similar to zygospores. (PI. V, Figs. 13-14.) 

China, Hupeh, Kiangsi, Anhwei, Szechwan, Shantung. 

57. Zygnema subfanicum Jao 1940. Sinensia. H, p, 295, PI. 4, 

Fig. I. 

Vegetative cells 24-26 /x x 30-65 /j., with 2 stellate chromatophores; 

conjugation scalariform; spores formed in one of the gametangia; re- 

ceptive gametangia enlarged on the conjugating side; zygospores glo- 

bose to subglobose, ju. 29-35 in diameter; median wall pitted; pits 7-8 /x 

in diameter, 1.8-2.7^1. apart, yellow-brown in color. (PI. V, Fig. 15.) 

China, Hunan. 

58. Zygnema transeauianum G. C. Couch 1944. Ohio Jour. Set. 

44, p. 277. 

Vegetative cells 30-32 /x x 20-60 /x; conjugation scalariform; recep- 

tive gametangia enlarged or slightly inflated on the conjugating side;

36 

ZYGNEMATACEAE 

zygospores globose to ovoid, 25-35^ x 33-40 ju, somewhat compressed; 

median spore wall yellow-brown, reticulate, with large irregular pits 

7-12 )Li across. 

United States: Arkansas, Boston Mountains. 

59. Zygnema stellinum (Vaucher) Agardh 1824. Systema Algarum, 

p. 77. 

Vegetative cells 28-38 /i x 27-ioo/A; conjugation scalariform, rarely 

lateral between occasional pairs of cells; zygospores in one of the gametangia; 

receptive gametangia inflated especially on the conjugating 

side; zygospores ovoid, 30-42 /j. x 35-48 (-57)/^; median spore wall yellow-brown, 

thick, scrobiculate; pits 3-4 i^^ in diameter, 3-4 /a apart; 

aplanospores common, usually cylindric, very rarely globose, the former 

filling the sporogenous cells, the latter occupying the middle of the 

cells; spore walls similar to those of the zygospores. (Pi. I, Fig. 8; 

PI. V, Fig. 16; and PL VI, Fig. i.) 

United States: Washington and California eastward, very common in 

the central and eastern states. 

Canada; Greenland; Europe; Asia; South America; North Africa. 

60. Zygnema cruciatum (Vaucher) Agardh 1817. Synopsis Algarum, 

p. 102. 

Vegetative cells 30-36 /it x 30-60 /x; conjugation scalariform; zygo- 


enlarged; zygospores globose to ovoid, 30-38 ju. x iu,; 32-40 median spore 

wall brown, scrobiculate; pits 1.5-2/A in diameter, i"- 3-5 apart; aplanospores 

short, cylindric-ovoid, 30-35 /a x 30-60 /x, filling the vegetative 

cells, otherwise similar to the zygospores. (PI. I, Fig. 9.) 

United States: Oklahoma; Iowa; Illinois; Massachusetts south to Mis- 

sissippi and Florida. 

Reported from all the continents. 

61. Zygnema cylindrosporum Czurda 1932. Siisswasserfiora Mit- 

teleuropa. 9, p. 122, Fig. 126. 

Vegetative cells 31-36 m x 60-80 m; conjugation scalariform; zygo- 


enlarged; zygospores short cylindric-ovoid to globose, 36-42 /x x 42-60 /a; 

median spore wall yellow-brown, scrobiculate; pits about 1.5-2 /a in 

diameter, 3-5/* apart; suture obliquely encircling the smaller circum- 

ference of the spore. (PI. VI, Fig. 2.) 

Macedonia; northern India; South Africa. 

62. Zygnema bohemicum Czurda 1932. Susswasserfiora Mittcl- 

europa. 9, p. 124, Fig. 128.

ZYGNEMA 37 

Vegetative cells 31-33/^ x 45-95/^; conjugation scalariform; zygo- 


enlarged on the conjugating side; zygospores ovoid to cylindric-ovoid, 

32-36^1 X 42-60 /x; median spore wall yellow-brown, thick, outwardly 

shallow pitted (visible only in section), and densely and finely verru- 

cose. (PL VI, Fig. 3.) 

Czechoslovakia. 

63. Zygnema mirandum Taft 1946. Trans. Amer. Micros. Soc. 

65, p. 24. 

Vegetative cells 28-35 /j- ^ 32-64 ft; conjugation scalariform; zygospores 

formed in one of the gametangia; receptive gametangia greatly 

enlarged on the conjugating side; zygospores compressed-globose to 

ovoid; median wall carinate; spore wall thin and smooth; median spore 

wall yellow-brown, of 2 layers, the outer thick and smooth, the inner 

reticulate, with the thin ridge crests irregularly broken; innermost 

spore wall smooth. (PI. VI, Fig. 4.) 

United States: Texas, Austin and Fredericksburg, April 22-24, ^93^- 

64. Zygnema inconspicuum Czurda 1932. Susswasserfiora Mtttel- 

europa. 9, p. 122, Fig. 127. 

Vegetative cells 36-39 /x x 50-70 /a; conjugation scalariform; zygospores 


scarcely enlarged; zygospores ovoid, sometimes extending into the en- 

larged tube, 40 /x X 50-60 ft; median spore wall brown, pitted; pits 4-5 

in diameter, 4-5 /^ apart. (PL VI, Fig. 5.) 

Finland; Manchuria; northern India. 

See also Number 86. 

65. Zygnema neocruciatum Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 212. 

Vegetative cells 40-50 /a x 30-100 /a; conjugation scalariform; zygo- 


slightly enlarged; zygospores globose to cyHndric-ovoid, filling the 

gametangia, 40-45/11 x 40-50^1; median spore wall brown, scrobiculate; 

pits about 2ft in diameter, 3-4 ft apart; aplanospores common and sim- 

ilar in size, rarely to 80 fi in length. 

United States: Illinois. Probably included in many records for Z. cruciatum 

elsewhere. 


66. Zygnema crassiusculum Transeau 1938. Amer. Jour. Bot. 

25, p. 524, Fig. 3. 

Vegetative cells ft 52-58 x 52-1 44 ft; conjugation scalariform; zygo-

38 

ZYGNEMATACEAE 

spores formed in one of the gametangia, compressed-globose to com- 

pressed-ovoid, 54-5^ M X 54-65/^ X 47-55/^; median spore wall brown, of 

2 layers, of which the outer is scrobiculate; pits about 2/^ in diameter, 

the inner finely and irregularly verrucose. (PI. VI, Figs. 6-7.) 

Africa, Cape Town (E. L. Stephens Coll.). 

67. Zygnema atrocoeruleum W. & G. S. West 1897. lûr. Roy. 

Micros. Soc. London, p. 476. 

Vegetative cells 14-17M 

-x 40-70/1. in diameter; conjugation scalar- 

iform; zygospores in one of the gametangia; receptive gametangia enlarged 

or inflated; zygospores globose, 2y-i.6{-2()) i^- in diameter; me- 

dian spore wall dark blue, smooth. 

England. 

68. Zygnema chalybeospermum Hansgirg 1888. Hedwigia. 27, 

P- 253- 

Vegetative cells 24-27 /a x 24-84 ju.; conjugation scalariform or lat- 

eral; zygospores in one of the gametangia; receptive gametangia cylindric 

or enlarged; zygospores globose to ovoid, 30-33 m x 30-38 /a; median 

spore wall blue, thick, smooth. (PI. VI, Fig. 8.) 

United States: Illinois, Casey; Michigan (Ackley Coll.). 

Europe; Asia; North Africa. 

69. Zygnema cyaneum Czurda 1932. Susswasserflora Mittcl- 

europa. 9, p. 127, Fig. 132. 

Vegetative cells 30-32 )u. x 45-60 m; conjugation scalariform or lat- 

eral; zygospores in one of the gametangia; receptive gametangia cylin- 

dric or slightly enlarged; zygospores globose to cylindric-ovoid, 30-34 /i- 

X 38-45 /a; median spore wall blue, thick, smooth. (PI. VI, Figs. 9-10.) 

Bohemia; India. 

70. Zygnema collinsianum Transeau 1914. Amer. Jour. Bot. 1, 

p. 289, PI. 25, Figs. 1-3. 

Vegetative cells 18-25 /a x 32-80 /a; conjugation scalariform; zygo- 

spores mostly in one of the gametangia, sometimes in one filament, 

sometimes in the other, rarely in conjugating tube, extending into both 

gametangia; receptive gametangia enlarged on the conjugating side; 

zygospores globose to ovoid, sometimes slightly compressed and show- 

ing a distinct equatorial suture, 26-40 ju. x 30-47 m; median spore wall 

blue at maturity, thick, pitted; pits 4-5 /a in diameter, 1-2 /a apart; aplanospores 

cyHndric-ovoid, 18-24/1 x 40-76/A, scattered among the vege- 

tative cells, similar in markings to zygospores. (PI. VI, Figs. 11-13.) 

United States: Oklahoma; Illinois; Indiana; Kentucky; Alabama. 

Northern India (Randhawa).

ZYGNEMA 39 

Named in honor of Frank S. Collins, author of Freshwater Algae of 

the United States and many contributions to both marine and fresh-water 

algology. 

71. Zygnema melanosporum Lagerheim 1884. Bot. Zentralbl. 

18, p. 279. 

Vegetative cells 22-27 /a ^ 36-100 fi; conjugation scalariform; zygospores 


slightly enlarged; zygospores ovoid to cylindric-ovoid, 23-30 /u, x 28-36 jia; 

median spore wall dark blue, finely punctate. 

United States: Ohio, Fayetteville, May, 1934. 

Sweden; North Africa. 

72. Zygnema excompressum Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 213. 

Vegetative cells 23-26 a^ x 32-80 ju; conjugation scalariform; zygo- 


enlarged; zygospores globose to subglobose, more or less compressed in 

the plane of the conjugating tube, 28yu, x 28-36 /x; median spore wall 

blue, carinate, scrobiculate; pits ju. 2.5-3 ^^ diameter and about the same 

distance apart. (PI. VI, Fig. 14.) 

United States: Oklahoma, Medford, April 26, 1932 (Taft Coll.). 

Bohemia. 

73. Zygnema peliosporum Wittrock 1868. Bot. Notiser. p. 190. 

Vegetative cells 23-30 /a x 24-80 /x; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia enlarged, or in- 

flated on the conjugating side; zygospores globose to ovoid, slightly 

compressed, 28-36 m x 28-46 /a; median spore wall blue, finely scrobic- 

ulate or punctate, with pits 1-2 /x in diameter, spaced 2-3 /a apart; equa- 

torial suture usually distinct, sometimes prominent; aplanospores cylin- 

dric-ovoid, smaller and with similar markings. (PI. VI, Fig. 17.) 

United States: California; Colorado; Texas; Indiana; Alabama. 

Sweden; Hungary; Spain; France; Norway; Finland; China. 

74. Zygnema azureum Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 214, PI. 17, Fig. 3. 

Vegetative cells 26-29 /* ^ 46-66 ju.; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia slightly to 

greatly enlarged; zygospores ovoid to cylindric-ovoid, 27-33 /x ^ 33-50 /x; 

median spore wall blue, finely punctate. (PI. VI, Fig. 15.) 

United States: Oklahoma; Illinois. 

75. Zygnema carinthiacum Beck 1929. Archiv f. Protist. 66, p. i. 

Vegetative cells 25-30 )U x 25-1 00 fi; conjugation scalariform; zygo-

40 

ZYGNEMATACEAE 

spores in one of the gametangia; receptive gamctangia much enlarged; 

zygospores globose to ovoid, 32-45/1 x 36-52/1; median spore wall blue, 

scrobiculate; pits 3-4/1 in diameter, 3-5/1 apart, (PL VI, Fig. 16.) 

United States: Oklahoma; Texas; Mississippi; Ohio; Florida. 

Austria; China. 

Forms with the same vegetative characters, but with smaller spores, 

have been collected in Ohio and Oklahoma. 

76. Zygnema pawneanum Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 214, PI. 18, Fig. 16. 

Vegetative cells 26-28/1 x 33-88/t; conjugation scalariform; zygo- 


on the inner side; zygospores globose, subglobose, or rarely ovoid, 

36-46/1 X 36-48/1; median spore wall blue when mature, pitted; pits 

7-11/1 in diameter, 2-3/1 apart. (PI. VII, Fig. i.) 

United States: Oklahoma; Louisiana (Taft Coll.); Ohio; Florida (J. D. 

Smith Coll.). 

In the Ohio collection some of the spores were distinctly tricarinate. 

The pits may be round or somewhat angular depending upon the height of 

the ridges between the pits. 

77. Zygnema ornatum (Li) Transcau 1934. Ohio Jour. Sci. 34, 

p. 420. Li. Ohio Jour. Sci. 33, p, 153, PL i, Figs. 9-10. 1933. 

Vegetative cells 27-32 /c x 34-96/1; conjugation scalariform; zygo- 

spores in one of the gametangia; receptive gametangia enlarged on the 

inner side, or cylindric; zygospores globose, subglobose to ovoid, 28-38/1 

x 32-38/1; median spore wall blue, pitted; pits about 6/1 in diameter 

and about 2/1 apart. (PL VII, Fig. 2.) 

United States: Oklahoma; Louisiana; Mississippi; Alabama. 

China, Nanking (L. C. Li Coll.). 

78. Zygnema excommune Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 213. Czurda. Siisswasserfiora Mitteleuropa. 

p. 119 (as Z. commune) 


spores formed in one of the gametangia; receptive gametangia greatly 

enlarged on the ccmjugating side; zygospores globose to ovoid, 40/1 x 

50/1; median spore wall blue, thick, scrobiculate; pits about 2.5/1 in 

diameter, about 4/1 apart, according to the figure. (PL VII, Fig. 3.) 

Bohemia. 

79. Zygnema catenatum Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 213. 

Vegetative cells 50-36/1 x 35-80/1; conjugation scalariform; zygo-

ZYGNEMA 41 

spores in one of the gametangia; receptive gametangia slightly enlarged 

on the conjugating side; zygospores globose to ovoid, slightly com- 

pressed, /i. 30-36 X 30-46^1; median spore wall blue, scrobiculate; pits 

1.5-2 ju. in diameter, 2-4 /^ apart; aplanospores similar, 30-34 /a x 30-80 /a, 

filling the cells. 


SPECIES REPRODUCING BY APLANOSPORES 

80. Zygnema frigidum Taft 1934. Trans. Amer. Micros. Soc. 53, 

p. 214, PI. 17, Fig. II. 

Vegetative cells 21-23JU, x 29-83/A; conjugation unknown; reproduc- 

tion by aplanospores, cylindric to tumid-cylindric with rounded ends, 

22-24^1 X 24-44 /x; niedian spore wall blue, scrobiculate; pits 1.5-2;". in 

diameter, 3-4 /t apart. (PL i, Fig. 6.) 

United States: Oklahoma; Texas. 

81. Zygnema spontaneum Nordstedt 1878. De Algis et Characeis 

Sandwicensibus, p. 17, PI. i, Figs. 23-24. 

Vegetative cells 16-22/i x 28-90 /a; reproduction by aplanospores 

only; aplanospores ovoid to cylindric-ovoid, 18-22^1 x 22-32 /x; median 

spore wall brown, scrobiculate; pits about 2iu in diameter, 3-5 /^ apart. 

(PI. VII, Figs. 5-7.) 

Hawaii; South Africa (E. Stephens Coll.); Java (Czurda); China (Jao). 

At all the above stations this species produced only aplanospores. The 

illustrations, published by G. S. West (1909) under this name, showing 

scalariform conjugations are better illustrations of Z. subtile than of this 

species. Nordstedt's original collection from Hawaii had cell diameters of 

i6-i8ju; the South African material, 18-20 /x; and the Szechwan specimens, 

19-22 ;u. 

82. Zygnema cylindricum Transeau 1915. Ohio Jour. Sci. 16, 

p. 22. 

Vegetative cells 28-33 ft x 28-66 /x; conjugation unknown; reproduction 

by akinetes and aplanospores; aplanospores cylindric to tumidcylindric, 

filling the cell, 30-33 /x x 24-54 /x; median spore wall brown, 

scrobiculate; pits about 3^ in diameter; suture irregular. (PI. VII, 

Fig. 9-) 

United States: Illinois; Indiana; Kentucky; Ohio. Common and generally 

distributed in April and May. 

South America, south Chile. 

83. Zygnema sterile Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 212. 

Vegetative cells 44-54 /^ x 22-69^1 with heavy cell walls, often with

42 

ZYGNEMATACEAE 

an outer pectic layer r>-i5/x in thickness; conjugation unknown; repro- 

duction by akinetcs; akinetes heavy-walled, completely filling the cells, 

brown at maturity, often distinctly colligate. (PI. VII, Fig. ii.) 

United States: Prairie regions of Oklahoma; Texas; Wisconsin; Michigan; 

Illinois; Indiana; Ohio. Not uncommon. 

Greece (Skuja, 1937); Asia Minor (Skuja, 1932). 

The brown color of the akinetes apparently results from chemical 

changes in the protoplasts and chromatophores. I have had this alga in 

cultivation during 2 successive years. It grew well, produced akinetes, which 

germinated and produced new filaments. During a 5 year period near 

Columbus, Ohio, it grew abundantly in a pond, but produced no spores. 

84. Zygnema quadrangulatum Jao 1940. Sinensia. H, p. 294, 

PI. 4, Fig. 3. 

Vegetative cells 24-27 /x x 25-100 /x, with 2 stellate chromatophores; 

reproduction by aplanospores only; aplanospores cyUndric-ovoid, 

25-29/A X 20-28 m; median spore wall dark blue, smooth, lamellate. 

(PI. VII, Fig. 14.) 

China, Hunan. 

85. Zygnema hypnosporum Rich 1935. Trans. Roy. Soc. S. Africa. 

23, p. 125. 

Vegetative cells about 33/^ in diameter, with 2 large stellate chromatophores; 

reproduction by aplanospores only; aplanospores cylindric- 

ovoid, 34/t X 34-70 m; median wall scrobiculate, blue. (PI. VII, Fig. 12.) 

Africa, South Rhodesia, July 3, 1930 (Stephens Coll.). 

86. Zygnema schwabei Krieger 1941. Zygnemales. Rabenhont' 

Kryptogamenfiora. 13, p. 261. 

Vegetative cells 17-20 /x x 36-71 m; reproduction by aplanospores 

only; spores cylindric filling the cells, 19-21 m x 37-70^; median spore 

wall thick yellow-brown, scrobiculate, pits 1-3 iî in diameter and 2-6 /a 

apart, with several irregular sutures. (PI. VII, Fig. 10.) 

South America, southern Chile. 

87. Zygnema borzae Krieger 1941. Zygnemales. Rabenhorst's 

Kryptoga?nenflora. 13, p. 264. 

Vegetative cells 24-26/i. x 18-55/x; reproduction by aplanospores 

only; aplanospores cylindric filling the sporangium wall, 14-27^ x 

1 8-54 m; median wall thick, blue, punctate with irregular elongate and 

variously curved pits 0.5/1 x i-2m in size. (PI. VII, Fig. 4.) 

streams. 

Rumania, Transylvanian Alps at 6,000 feet, attached to stones in

ZYGNEMA 43 

88. Zygnema subcylindricum Krieger 1941. Zygnemales. Raben- 

horst's Kryptogamenflora. 13, p. 262. 

Vegetative cells 28-35 /a ^ 54~7i'^5 reproduction by aplanospores 

only; spores cylindric filling the cells, 29-33 m ^ 55~70^5 median wall 

brown, granulose and with shallow pits, 

(PL VII, Fig. 13.) 

and 1-2 m irregular sutures. 

Germany; Bohemia. 

This is the Z. cylindricum figured by Czurda. It differs from Z. cylindrtcum 

Transeau in the granulose markings on the spore wall. 

89. Zygnema irregulare Krieger 1941. Zygnemales. Rabenhorst's 

Kryptogamenflora. 13, p. 263. 

Vegetative cells 40-42 /a x 68-82 ju,; reproduction by aplanospores 

only; spores cylindric-ovoid with very heavy walls; median wall brown, 

outwardly finely verrucose, with irregularly and widely separated pits 

3-6m in diameter and 4-26/i. apart. (PI. VII, Fig. 8.) 

Germany, Mark Brandenburg. 

SPECIES NOT IN PROPER SEQUENCE 

90. Zygnema mucigenum Randhawa 1938. Proc. Indian Acad. 

Sci. 8, p. 141, Fig. 25. 

Vegetative cells 12-14/A x 50-100^1; conjugation both lateral and 

scalariform; zygospores in one of the gametangia, which is enlarged 

near the spore; zygospores compressed-globose, 20-22 jia x 30-36^; me- 

dian spore wall dark blue-green, with scattered punctations; pits 1-1.5^^ 

in diameter, 3-4M apart. (PI. XLI, Figs. 6-7.) 

India, Fyzabad district, December 15, 1937. 

Should be placed near Number 68. 

91. Zygnema gangeticum Rao 1937. Jour. Indian Bot. Soc. 16, 

p. 270. 

Vegetative cells i6-20iu. x 40-60 /x; conjugation scalariform and lat- 

eral, zygospores formed in the conjugating tubes and extending into 

the gametangia; zygospores globose to ovoid, 30-36 /x x 30-45 m; median 

spore wall yellow-brown and smooth. 

India, United Provinces, Ganges. 

Should be near Number 3. 

92. Zygnema kwangtungense Ley 1944. Sinensia. 15, p. 97. 

Vegetative cells 38-42 ju. x 25-75 /x; conjugation scalariform; recep- 

tive gametangia slightly inflated; zygospores globose or subglobose, 

slightly compressed, 44-61 ju, x 39-72 /a; outer spore wall smooth, transparent; 

median wall 7-iiAc thick, lamellate and foveolate; pits very

44 

ZYGNEMATACEAE 

irregular in form and diameter, i. 8-6.5 /x, 1-8-7.2^ apart, brown at 

maturity. (PI. VII, Fig. 15.) 

China, rice fields, Tong-Kau, North Kwangtung, March 20, 1942. 

Should be near Number 61. 

93. Zygnema ellipsoideum Jao 1947. Bot. Bull. Acad. Stnica. 1, 

p. 97. 

Vegetative cells 20-22 ju. x 25-40 /n; conjugation unknown; aplan- 

ospores ellipsoid, with somewhat pointed ends, 15-20^ x 22-25 (-30) m; 

median spore wall yellow-brown, scrobiculate; sporiferous cells cylin- 

dric, or somewhat inflated on one side. 

China, Kwangsi, Suijen, May 31, 1938; fairly common in rice fields. 

This is the first species with ellipsoid spores to be described. 

Fig. a.—Zygnema etlipsoideuni aplanospores and sporangia. Figs. B. and C. 

Zygnema mirificnm aplanospores, immature and mature. Both figures after Jao. 

94. Zygnema mirificum Jao 1947. Bot. Bull. Acad. Sinica. 1, p. 97. 

Vegetative cells i5-i8iu, x 25-63 /a; conjugation unknown; outer 

aplanospore wall similar in shape and just inside the dolioform sporangium 

wall, 22-30 /J. x 30-60 /A the median wall varies from ellipsoid to 

ovoid in the bulge of the outer wall, 20-30 m x 25-30 ju.. The space between 

the 2 walls is filled with yellowish colloidal material. The 

median wall is irregularly and minutely scrobiculate, yellow-brown in 

color. 

China, Kwangsi, Suijen, June 17, 1938; in rice fields, very common. 

This is a new type of 7,ygnema spore, with a colloidal layer between the 

outer and median walls, and the 2 walls not of the same form. It is probable, 

however, that the "granulose" surfaces of the median walls of certain other 

species result from the coagulation of a preceding colloidal layer. 

95. Zygnema khannae Skuja 1949. Nova Acta Soc. Sci. Upsali. 

Ser. 4, 14, p. 99. PI. 22, Figs. 6-7. 

Vegetative cells 24-28/1 x 30-70/1, conjugation unknown; reproduc-

ZYGNEMA 45 

Figs. D and E. Zygnema lihannae aplanospores with outer wall cylindric, and 

median wall ellipsoid or ovoid. After Skuja. 

tion by aplanospores, the outer wall of which is cylindric, just inside the 

sporangium wall, densely punctate; the median wall, formed after con- 

traction, varies from ellipsoid to ovoid, 22-25 11 x 25-46 /j., yellow-brown 

with shallow irregular pits 1.5-5 /a ^^ diameter. 

Burma, near Rangoon, 1936. (L. P. Khanna Coll.). 

List of the Species of ZYGNEMA with Number 

adpectinatum Transeau 1934 

13 

areolatum Taft & Transeau 1934 

15 

atrocoeruleum W. & G. S. West 1897 

67 

azureum Taft 1934 74 

bohemicum Czurda 1932 

borzae Krieger 1941 

calosporum Jao 1935 

4^ 

carinatum Taft 1934 35 

carinthiacutn Beck 1929 75 

carterae Czurda 1932 

2 

catenatum Transeau 1934 79 

chalybeospermum Hansgirg 1888 

68 

chungii Li 1934 

10 

circumcarinatum Czurda 1930 33 

coeruleum Czurda 1932 26 

collinsianum Transeau 1914 ']o 

conspicuum (Hassall) Transeau 1934 6 

crassiusculum Transeau 1938 66 

cruciatum (Vaucher) Agardh 1817 

60 

cyaneum Czurda 1932 69 

cyanosporum Cleve 1868 

22 

62 

07

46 

ZYGNEMATACEAE 

cylindncum Transeau 191 5 82 

cylindrospermum (W. & G. S. West) Kricgcr 1941 38 

cylindrosporum Czurda 1932 61 

czurdae Randhawa 1936 23 

decussatutn (Vaucher) Agardh 1824 4 

ellipsoideum Jao 1947 93 

excommune Transeau 1934 78 

excompressum Transeau 1934 72 

excrassitm Transeau 1934 

18 

exteniie Jao 1935 40 

fanicum Li 1934 56 

flaviim Taf t 1946 47 

jrigidum Taft 1934 

80 

gangeticum Rao 1937 

9^ 

gedeanum Czurda 1932 

21 

germanicum Czurda 1932 54 

giganteum Randhawa 1936 

20 

globosum Czurda 1932 

12 

goraf^hporense Singh 1938 27 

liausmannii (De Notaris) Czurda 1932 44 

himalayense Randhawa 1940 5 

hypnosporum Rich 1935 

85 

inconspicuum Czurda 1932 

insigne (Hassall) Kiitzing 1849 55 

insignisporum Couch 1944 

5^ 

irregulare Krieger 1941 89 

khannae (Skuja) 1949 95 

lîangsiense Li 1938 29 

/^tcangtungense Ley 1944 

laetevirens Klebs 1886 

laevisporum Jao 1935 3 

lawtonianum Taft 1934 

8 

leiospermiim de Bary 1858 43 

Ittteosportim Czurda 1932 46 

majus Czurda 1932 

28 

melanosporum Lagerheim 1884 71 

micropunctatum Transeau 1934 

3^ 

mirandum Taft 1946 63 

mirificum Jao 1947 94 

momoniense W. West 1892 32 

mucigcnum Randhawa 1938 90 

64 

9^ 

16

ZYGNEMA 47 

neocruciatum Transeau 1934 65 

neopectinatum Transeau 1934 

19 

normani Ta£t 1934 

50 

ornattim (Li) Transeau 1934 77 

oveidanum Transeau 1934 

i 

pawhus\ae Taft 1934 34 

pawneanum Taft 1934 7^ 

pectinatum (Vaucher) Agardh 1817 17 

peliosporum Wittrock 1868 73 

pseudopectinatum Czurda 1932 14 

quadrangulatum Jao 1940 84 

ralfsii (Hassall) de Bary 1858 30 

schwabei Krieger 1941 86 

sinense Jao 1935 

11 

sûjae Czurda 1932 7 

spontaneum Nordstedt 1878 

81 

stagnale (Hassall) Kiitzing 1849 36 

stellinum (Vaucher) Agardh 1824 59 

sterile Transeau 1934 

83 

subcruciatum Transeau 1934 53 

subcylindricum Krieger 1941 

88 

subjanicum Jao 1940 57 

substellinum Taft 1934 45 

subtile Kiitzing 1849 37 

synadelphum Skuja 1926 24 

tenue Kiitzing 1849 42 

terrestre Randhawa 1938 25 

tholosporum Magnus & Wille 1884 41 

transeauianum G. C. Couch 1944 58 

vaginatum Klebs 1886 52 

vaucherii Agardh 1824 49 

verrucosum Jao 1935 9 

yunnanense Li 1940 39

CHAPTER THREE 

THE GENUS ZYGNEMOPSIS (SKUJA) TRANSEAU 1934 

The vegetative filaments of the 24 species here classified are 

usually indistinguishable from those of Zygnema. They may have 

a thin, or a thick, pectic sheath and they have been found floating 

in ponds, ditches, and slow flowing streams, not infrequently 

associated with other species of Zygnemataceae. 

At the beginning of the reproductive phase, however, they 

may be distinguished by the partial replacement of the usual cell 

contents by a transparent refractive gel. Whether the cells become 

gametangia, or aplanosporangia, some of them lengthen and suc- 

cessive layers of cellulose are deposited as the protoplast contracts 

to the middle of the cell. At maturity the zygospores have four, 

and the aplanospores two, lamellate solid appendages attached to 

them. As seen in the illustrations, these may be short and stubby, 

or may be very much longer than the original vegetative cell. 

All the 19 zygosporic species have isogamous gametes and 

scalariform conjugation. After the papillae unite in sexual repro- 

duction the tube is exceedingly narrow, but soon broadens in the 

plane of the filaments. The zygospore resulting from fusion of 

the gametes is a compressed, more or less quadrangular pillow- 

shaped, body which may subsequently become lenticular or irregular 

in outline. Both the tube development and spore forms 

resemble those of the quadrangular-spored species of Mougeotia 

more than those of any species of Zygnema. The outer or firstformed 

wall bounds the colloidal gel and is composed of cellulose. 

The median wall is chitinous and in at least one species consists 

of two layers. Not infrequently yellow or brown granules are 

deposited between the outer and median walls and may obscure 

the surface features of the median wall. The innermost wall is 

transparent and thin and can be seen only when the spore is 

crushed. Parthenospores are not infrequent in some collections. 

They have walls similar to those of the zygospores, but are ovoid, 

smaller, and laterally placed in the gametangia. Aplanospores are 

common in 5 of the species. They vary in form from ovoid to 

ellipsoid and have walls similar to those of the zygospores. 

49

50 

ZYGNEMATACEAE 

When the zygospores are fully mature, an equatorial suture 

usually can be seen. In many collections the median wall is con- 

tracted inwardly and the surface thrown into ridges. The ridges 

are irregular in position and are not morphological features of the 

wall. They disappear when the spores are treated with dilute 

potassium hydroxide, while morphological features of the wall 

become more distinct. 

The species of Zygnemopsis may be distinguished readily from 

those of Zygnema when in a fruiting condition by the cellulose 

colloid accumulation in the cells, by the initial very narrow con- 

jugating tubes, and by the round or quadrangular pillow-shaped 

spores. They differ from the species of Zygogonium in the form 

of the chromatophores, the absence of cytoplasmic residues in the 

gametangia and sporiferous cells, in the form of the spores, and 

in the stages of tube formation. From the species of Debarya they 

may be distinguished by the Zygnema-like chromatophores; and 

from Hallasia by the absence of aplanospores from which one, 

two, or three sporelings develop. 

Some of the species here classified in the genus Zygnemopsis 

have been previously placed in the genera: Debarya, Mougeotia, 

and Zygnema. 

Key to the Species of ZYGNEMOPSIS 

I. Reproducing by aplanospores 12 

I. Reproducing by zygospores, sometimes aplanospores also 2 

2. Diameter vegetative cells mostly less than Sjtt 3 

2, Diameter vegetative cells mostly between 8 and 16 /a 4 

2. Diameter vegetative cells mostly 16 /a or more 11 

3. Median spore wall punctate, yellow, 

diameter vegetative cells 4-6 /a i. Z. silvangen sis 

3. Median spore wall smooth, goldenbrown, 

diameter vegetative cells 6-7/^'. 2. Z.orientalis 

3. Median spore wall scrobiculatc, yellow, 

diameter vegetative cells 6-8 /i. 4. Z. floridana 

4. Shorter axis of zygospores less than 32 /i 5 

4. Shorter axis of zygospores 32/i. or more 8 

5. Diameter vegetative cells mostly less than 12/1 6 

5. Diameter vegetative cells mostly more than i2ij- 7 

6. Median spore wall smooth, choco- 

late brown 5. Z. minuta

ZYGNEMOPSIS 51 

6. Median spore wall punctate, yellow-brown 

6. Z. desmidioides 

6. Median spore wall punctate, chest- 

nut brown 7. Z. columbiana 

6. Median spore wall punctate, yellow 9. Z. tiffaniana 

6. Median spore wall scrobiculate, yellow 

10. Z. sinensis 

6. Median spore wall finely scrobic- 

ulate, yellow-brown 8. Z. americana 

7. Median spore wall scrobiculate, yellow, 

pits 2-3 II 10. Z. sinensis 

7. Median spore wall scrobiculate, yellowbrown, 

granulose 12. Z. splendens 

8. Median spore wall punctate, or 

undulate, granulose 15. Z. iyengarii 

8. Median spore wall punctate, choc- 

olate brown 17. Z. sphaerospora 

8. Median spore wall scrobiculate 9 

9. Zygospores 32-36/^ x 36-42 /x, golden 

yellow, suture 14. Z. stephensiae 

9. Zygospores with shorter axis more than ju. 36 10 

10. Median spore wall smooth or undu- 

late, yellow-brown, granulose 11. Z. indica 

10. Median spore wall deeply scrobic- 

ulate, pits 2-4 /i angular i3- 2^- wiichangensis 

10. Median spore wall scrobiculate, pits 

jLt 

3 round 16. Z. quadrata 

II. Zygospores 36-52 /x, brown to green... 18. Z.lamellata 

1 1 . Zygospores 24-30 [i- x 30-48 [i, brown ... 20. Z. decussata 

II. Zygospores 28-36 ft x 48-60 m, brown. . . 21. Z. spiralis 

12. Vegetative cell diameter 8 /a or less 3, Z. gracilis 

12. Vegetative cell diameter 14-22 /x 13 

12. Vegetative cell diameter 30-50JU. 14 

13. Spores spindle-shaped, median wall 

scrobiculate 19. Z. transeauiana 

13. Spores ovoid, truncate, median wall 

scrobiculate 20. Z. decussata 

13. Spores compressed-ovoid, tricarinate. . 22. Z.jertilis 

14. Spores elHpsoid to ovoid, diameter 

40-55 /A 24. Z. hodgettsii 

14. Spores ellipsoid to ovoid, diameter 

70-94 /i 23. Z. pectinata

52 

ZYGNEMATACEAE 


1. Zygnemopsis sikancensis Li 1939. Bull. Fan Mem. Inst. Biol., 

Botany. 9, p, 225. 

Vegetative cells 4-6 /î x 38-68 m, each with 2, sometimes 4, chro- 

matophores; conjugation scalariform; zygospores quadrangular-ovoid, 

1 8-22 M X 1*6-22 ix, filling the tube and extending into the gametangia; 

median spore wall yellow and punctate. (PI. VIII, Figs. 1-2.) 

China, Sikang, Yunnan. 

2. Zygnemopsis orientalis (Carter) Transeau 1944. Ohio Jour. 

Sci. 44, p. 244. Records Bot. Surv. India. 9, p. 281. 1926 

(as Debarya desmidioides var. orie?itale Carter). 

Vegetative cells 6-7/^ x 30-67/1; conjugation scalariform; zygo- 

spores quadrangular, pillow-form, 20-25 /a on a side, filling the broad 

tubes and dividing the gametangia; median spore wall golden-brown, 

whether smooth or punctate not stated. (PI. VIII, Figs. 3-5.) 

India, Matiana on the Tibetan road from Simla, altitude 8,500 feet, 

April 30, 1907. 

3. Zygnemopsis gracilis Randhawa 1938. Proc. Indian Acad. Sci. 

8, p. 133, Fig. 18. 

Vegetative cells 6-7 /j. x 40-70 /x; reproduction by aplanospores 

formed in spindle-shaped sporangia, with spores in the median region; 

spores globose to ovoid, about 20 jx in diameter; color and markings on 

the median wall undetermined. (PI. VIII, Figs. 6-7.) 

India, Makrahi, Fyzabad, U.P., March 12, 1938. 

4. Zygnemopsis floridana Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 215, PI. 18, Fig. 20. 

Vegetative cells 7-8 /x x 30-40 (-50) m; chromatophores 2, pillow- 

form, each with a pyrenoid; conjugation scalariform; zygospores 

formed in the greatly enlarged conjugating tubes and extending but 

little into the gametangia which lengthen during conjugation to 50-90 jia; 

spores ovoid to quadrate-ovoid, 18-25/1 x 28-30/1; median spore wall 

bright yellow, scrobiculate; pits 2-3/1 in diameter and about the same 

distance apart. (PI. VIII, Figs. 8-9.) 

United States: Florida, Fort Myers, May 25, 1933 (Blaydes Coll.). 

5. Zygnemopsis minuta Randhawa 1937. Pôc. Indian Acad. Sci. 

5, p. 312, Fig. 8. 

Vegetative cells 8-1 2 /t x ^0-70/1, each with 2 compressed-ovoid 

chromatophores; conjugation scalariform, dissociation occurring dur- 

ing or after conjugation; zygospores globose to quadrate-globose.


22-25 jLi X 25-30 /"-; outer spore wall hyaline; median wall thick, chocolate 

brown, smooth; aplanospores more abundant than zygospores, 

asymmetrically ovoid to globose, sometimes with the 2 ends slightly 

produced, 18-20/J. x 18-31 /x. (PI. VIII, Figs. lo-ii.) 

United States: Michigan, Douglas Lake region (Taft Coll.). 

India, Fyzabad, U.P., March, 1937. 

6. Zygnemopsis desmidioides (W. & G. S. West) Transeau 1934. 

Trans. Amer. Micros. Soc. 53, p. 215, Fig. 25. 

Vegetative cells 8-1 i/x x 19-56 m, constricted at the ends; chroma- 

tophore an axial plate with 2 pyrenoids; filaments fragment readily; 

"conjugation between free cells" scalariform; zygospores formed in the 

broad conjugating tubes and extending somewhat into both gametangia; 

spores quadrangular with straight, concave, or slightly convex 

sides and rounded angles, 14-18 m x 18-24 jw; median spore wall goldenbrown, 

thick, finely punctate. (PI. VIII, Figs. 12-14.) 

United States: Wisconsin. 

England; Latvia. 

The statement by West that conjugation takes place between free cells 

is probably incorrect. Fragmentation of filaments occurs during and after 

conjugation in several other species. The filaments of Z. desmidioides have 

a pectic sheath. When conjugation occurs this sheath passes into solution 

and, as the gametangia become distended with pectic compounds, the ends 

become rounded and separate. 

7. Zygnemopsis columbiana Transeau 1934. Trans. Amer. Mi- 

cros. Soc. 53, p. 215, Figs. 27-29. 

Vegetative cells (8-) 9.5-11.5/x x 40-ioo/x, with 2 pillow-shaped 

chromatophores, each with a central pyrenoid; conjugation scalariform; 

zygospores formed in the wide conjugating tubes and extending far 

into each gametangium; spores quadrate-ovoid, 23-32 /a x jU-, 23-34 with 

angles rounded, produced, or retuse; median spore wall with a prom- 

inent suture, finely punctate, chestnut brown; aplanospores ellipsoid to 

ovoid, 1 8-20 /x X 25-30^1, otherwise similar. (PI. VIII, Figs. 15-17.) 

Canada, British Columbia (W. R. Taylor Coll.). 

8. Zygnemopsis Americana Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 215. 

Vegetative cells 9-12 /a x 27-100 /x; 2 compressed-ovoid chromato- 

phores; conjugation scalariform; zygospores formed in the broad con- 

jugating tubes and extending far into both gametangia; spores ovoid to 

quadrate-ovoid, 20-40 /a x 30-40 /a; parthenospores 15-20 ft x 20-30 ju., 

unilaterally ellipsoid with retuse ends; median spore wall minutely

54 

ZYGNEMATACEAE 

scrobiculate, usually hidden by layer of yellow-brown granules between 

the outer and median walls. (PI. VIII, Figs. 18-21.) 

United States: Michigan, Douglas Lake region; Wisconsin, Madison. 

Canada, Ontario (A. B. Klugh Coll.). 

9. Zygnemopsis tiffaniana Transeau 1944. Ohio Jour. Sci. 44, 

p. 244. Formerly listed as Debarya cruciata and Z. cruciata 

Price (191 1). 

Vegetative cells io-i2;u. x 30-60/^; chromatophore with 2 pyrenoids; 

conjugation scalariform; zygospores formed n\ the broad conjugating 

tubes and extending into both gametangia; spores quadrangular with 

concave or rarely straight sides, angles produced or slightly concave, 

20-24/x X 28-32^; median spore wall yellow, punctate. (PI. VIII, 

Figs. 22-23.) 

United States: Florida (Tiffany Coll.); Oklahoma (Taft Coll.). 

Canada, British Columbia (Wailes Coll.). 

Named for Hanford L. Tiffany of Northwestern University, author of 

The Oedogoniaceae and Algae, the Grass of many Waters. 

In 1932 there was but one incompletely described species with approximately 

these dimensions. Now there are several with mature spores and 

it is impossible to say which species Price had in 1911. The American col- 

lections are clearly representatives of a single species, and not necessarily 

"Z, cruciata." 

10. Zygnemopsis sinensis Transeau 1934. Trails. Amer. Micros. 

Soc. 53, p. 215, Fig. 22. 

Vegetative cells 10-13JU. x 29-72/.S with 2 more or less elongate, 

stellate chromatophores; conjugation scalariform; zygospores formed 

in the broad conjugating tubes and extending far into both gametangia; 

spores quadrate-ovoid, 29-32 /a x 29-36 /a; median spore wall yellow, 

scrobiculate; pits 2-2.5 /u, ^^ diameter, 2.5-3 /a apart. (PI. VIII, Fig. 24.) 

China, Wuchang, Hupeh (Li Coll.). 

11. Zygnemopsis indica Randhawa 1937. Proc. Indian Acad. Sci. 

5, p. 297, Fig. I. Also as Ghosella indica. 1934. 

Vegetative cells 10-15/^ x 50-75/^., with 2 rounded or stellate chro- 

matophores, each with a central pyrcnoid; reproduction by zygospores, 

parthenospores, and aplanospores; conjugation scalariform; zygospores 

compressed-cjuadrangular-ovoid or compressed-globose, 34-46/ii x 40- 

53/A; median wall yellow-brown, smooth or undulate, with abundant 

granules between the outer and median walls; aplanospores and par- 

thenospores with similar walls, 20-26/^1 x 40-46/Li, in sporangia to 8om 

in length. (PI. VIII, Figs. 26-27.) 

India, Punjab near Hamira, February to April, 1930.


12. Zygnemopsis splendens Randhawa 1937. Proc. Indian Acad. 

Sci. 5, p. 297, Fig. 2. 

Vegetative cells 12-15 /x x 30-42 /x, with 2 more or less rounded 

chromatophores; conjugation scalariform; zygospores varying from 

compressed-ovoid to quadrangular-ovoid, 26-30 jU, x 40-50 /a; outer wall 

blue, median wall yellow-brown, scrobiculate with pits 1-2 ju. in diameter; 

often a layer of brownish granules between the outer and median 

walls. (PL VIII, Fig. 25.) 

India, Fyzabad, U.P., January to March, 1937. 

13. Zygnemopsis wuchangensis Li 1937. Bull. Fan Mem. Inst. 

Biol., Botany. 8, p. 18. 

Vegetative cells 12-15 jU, ^ 32-84^1, each with 2 stellate chromato- 

phores; conjugation scalariform; zygospores quadrangular-ovoid, 

36-56 /A X 42-64^1. X 28-35 jU. i^ thickness; median spore wall yellow, 

angularly scrobiculate, with very deep distinct pits, 2-4 ^c in diameter, 

and with a distinct suture. (PI. VIII, Figs. 28-29.) 

China, Wuchang, Hupeh. 

14. Zygnemopsis stephensiae Transeau 1934- Trans. Amer. 

Micros. Soc. 53, p. 215, Fig. 21. 

Vegetative cells 12-15^1. x 36-60 /j-, with 2 more or less stellate chro- 

matophores; conjugation scalariform; zygospores formed in the greatly 

enlarged conjugating tubes and extending into both gametangia, which 

are otherwise filled with pectic-cellulose material; spores quadrately 

ovoid, 32-36 /A x 36-42 /U.; with angles rounded or truncate, and sides 

straight or concave; median spore wall yellow, irregularly scrobiculate, 

pits about 2-4 /A in size. (PI. IX, Fig. i.) 

South Africa, Cape Colony (Stephens Coll.). 

15. Zygnemopsis iyengarii Randhawa 1937. Proc. Indian Acad. 

Sci. 5, pp. 306-8, Figs. 5-6. 

Vegetative cells 12-16 /a x 60-120 m, with 2 more or less rounded 

chromatophores in each cell; conjugation scalariform; zygospores 

formed in the greatly distended tube and extending into the gam- 

etangia; zygospores compressed-globose to ovoid, /u. 38-54 in diameter, 

with a thick outer blue wall, a smooth or undulate yellow-brown 

median wall, which is variously wrinkled by unequal contraction; with 

a few or many granules between the walls; aplanospores ovoid to 

spindle-shaped, 24-28^1 in diameter, with similar walls. (PI. IX, 

Figs. 2-3.) 

India, Fyzabad, U.P., January, 1937. 

On shrunken spores there are ridges, variously disposed, which disappear 

when a dilute potassium hydroxide solution is applied.

56 

ZYGNEMATACEAE 

i6. Zygnemopsis quadrata Jao 1935. Sinensia. 6, p. 573, PI. 2, 

Figs. 26-30. 

Vegetative cells 13-16/U x 29-71 /^; 2 (rarely 3 or 4) chromatophores; 

conJLigaiion scalariform; fertile cells slightly geniculate; zygospores in 

the conjugating lubes often extending into the gametangia; zygospores 

compressed-ovoid to quadrangular-ovoid, 38-48/a x 45-6o)u. x 29-32/x; 

outer wall smooth, transparent, usually remote from the median layer; 

median layer golden yellow, scrobiculate; pits about 3^ in diameter, 

1.5-2.5/X apart, suture prominent. (PI. IX, Figs. 4-5.) 

China, Szechwan, rice farms and pools. 

17. Zygnemopsis sphaerospora Randhawa 1938. Proc. Indian 

Acad. Sci. 8, p. 131, Fig. 16. 

Vegetative cells 14-16^1 x 45-50/A, with 2 chromatophores; reproduction 

by zygospores; conjugation scalariform; zygospores com- 

pressed-globose, 34-38/^ in diameter; median spore wall chocolate 

brown, punctate; pits about .5//. in diameter. (PI. IX, Figs. 6-7.) 

India, Fyzabad, U.P., May, 1938. 

18. Zygnemopsis lamellata Randhawa 1937. Proc. Indian Acad. 

Sci. 5, p. 302, Figs. 3-4. 

Vegetative cells 13-18 /x x 32-52 m, with 2 stellate chromatophores; 

reproduction by zygospores; conjugation scalariform, some gametangia 

lengthening to /u-; 98 zygospores usually compressed, quadrately ovoid, 

sometimes compressed-globose; sporangia with thick, lamellate walls; 

zygospores 36-48 û x 36-52/^1; outer wall transparent; median wall of 

2 layers, of which the outer is blue and undulate at full maturity, and 

the inner finely scrobiculate, yellow to brown in color. Sometimes there 

are also yellow granules between the walls. (PI. IX, Figs. 8-9.) 

India, Fyzabad, U.P., February to April, 1937. 

19. Zygnemopsis transeauiana Randhawa 1938. Proc. Indian 

Acad. Sci. 8, p. 132, Fig. 17. 

Vegetative cells 14-18/x x 25-50 ju., with 2 chromatophores more or 

less rounded and near the middle of the cell, regardless of its length; 

reproduction by aplanospores. During the development of the sporangium 

the cells may elongate to 90-144/1 and increase in thickness to i9Ai. 

As the protoplast contracts, pectic compounds and cellulose accumulate, 

and the middle of the sporangium enlarges in diameter (up to 35^)- 

The outer spore wall is colorless and adherent to the pectic gel. Between 

this wall and the median wail yellow or brown granules may 

accumulate. The median wall is ovoid to compressed-globose, 16-25 /a x


23-50 Ai, with a more or less prominent suture, yellow and scrobiculate, 

with pits 2-3 M in diameter. (PI. IX, Figs. lo-ii.) 

India, Fyzabad, U.P., February to April. 

20. Zygnemopsis decussata Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p, 214. Includes Zygnema pseudodecussatum 

Czurda 1932. 

Vegetative cells 16-20/t x 24-50 /.i; chromatophores as in Zygnema, 

each with i pyrenoid; conjugation scalariform; zygospores extending 

far into each gametangium, ovoid to quadrate-ovoid, and irregular, 

24-30 /A X 30-48 ju., the angles rounded, retuse, or produced; aplan- 

ospores unilaterally ovoid, the plane of the convex side changing in 

successive cells, 17-25 i", x 20-40 û.; parthenospores 15-20;^, x 20-30 û.; 

median wall in all the spores scrobiculate; akinetes with smooth, heavy 

walls, 1 8-20 /i x iU,. 20-36 (PI. IX, Figs. 12-15.) 

United States: Oklahoma; Iowa; Arkansas; Illinois; Kentucky; Mich- 

igan. 

Canada, Ontario; Europe, Bohemia; China, Szechwan. 

Some collections have only aplanospores, others only scalariform conjugation 

and zygospores, still others have filaments with both zygospores 

and aplanospores. In Illinois the size of the filaments was regularly 18-20M 

in diameter, but I have a collection sent me by Dr. Li from Amoy, China, in 

which some of the conjugating filaments have diameters as low as 12/x. 

The zygospores, however, are of the usual dimensions. 

21. Zygnemopsis spiralis (Fritsch) Transeau 1934. Trans. Amer. 

Micros. Soc. 53, p. 214. 

Vegetative cells 18-25/U- x 26-60 /x, with 2 stellate chromatophores; 

conjugation scalariform; gametangia sometimes elongating to 130/^; 

zygospores quadrately ovoid, 28-36 /^ x 48-56^1.; outer wall thin or thick, 

transparent, usually separated from the median wall and sometimes 

covered internally with granules; median wall punctate or finely scro- 

biculate. (PL IX, Fig. 16.) 

United States: Wisconsin; Michigan (Prescott Coll.). 

South Africa, Table Mountain, wet rock on slope, luly 19, 1908; Latvia 

(Skuja Coll.). 

22. Zygnemopsis fertilis (Fritsch & Rich) Transeau 1934. Trans. 

Amer. Micros. Soc. 53, p. 216. 

Vegetative cells 20-22 /j. in diameter; slight constrictions between 

the cells; chromatophores 2, stellate; zygospores unknown; sporogenous 

cells distended in the center; aplanospores compressed-ovoid, 31-32 /j- x 

41-49 /x; median spore wall with 3 

spores immature. (PI. IX, Fig. 17.) 

South Africa. 

(or more) longitudinal ridges;

58 

ZYGNEMATACEAE 

23. Zygnemopsis pectinata (Fritsch) Transeau 1934. Trans. 

Amer. Micros. Soc. 53, p. 216. Ohio Jour. Sci. 25, p. 198, 

Figs. 38-44. 1925. 

Vegetative cells 36-42 ^ x 83-200 ju-; chromatophores 2, stellate or 

elongated stellate, each with a pyrenoid or rarely 2 or 3 pyrenoids; 

zygospores unknown; akinetes swollen toward the middle to 80 m, with 

walls 6-8 /i thick, sometimes obliquely ventricose, alternating in succes- 

sive cells; aplanospores ellipsoid, or with polar thickenings, 70-94 ^ x 

ioo-i28iit; outer spore wall 4-8^1 thick, smooth; median spore wall 

irregularly granulose. (PI. IX, Figs. 18-21.) 

South Africa, Kentani District. 

The specimens upon which this description is based have an amazing 

variety of chromatophores only illustrated in part in the publication of 1925. 

None of the spores examined is believed to be fully mature. 

24. Zygnemopsis hodgettsii Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 216. Hodgetts. Trans. Roy. Soc. S. Africa. 13, 

p. 67. 1925. 

Vegetative cells ju- 35-50 x yu, 20-75 ^^ diameter, with 2 stellate chromatophores; 

zygospores unknown; aplanospores ovoid, 40-55^ x 

65-8ojLi, immature. (PI. IX, Fig. 22.) 

South Africa, Stellenbosch. 

This and the 2 preceding species are obviously imperfectly described 

species, but have characteristics that clearly place them in this genus, and 

not in the genus Zygnema. 

List of the Species of ZYGNEMOPSIS with Number 

americana Transeau 1934 

cokimbiana Transeau 1934 7 

decussata Transeau 1934 

20 

desmidioides (W. & G. S. West) Transeau 1934 

6 

jertilis (Fritsch & Rich) Transeau 1934 22 

floridanu Transeau 1934 4 

gracilis Randhawa 1938 3 

hodgettsii Transeau 1934 

indica Randhawa 1937 11 

iyengarii Randhawa 1937 

lamellata Randhawa 1937 18 

7ninuta Randhawa 1937 5 

orientalis (Carter) Transeau 1944 2 

pectinata (Fritsch) Transeau 1934 ^3 

8 

24 

15

quadrata Jao 1935 


sikangensis Li 1939 

i 

sinensis Transeau 1934 

10 

sphaerospora Randhawa 1938 17 

spiralis (Fritsch) Transeau 1934 21 

splendens Randhawa 1937 

12 

stephensiae Transeau 1934 14 

tiffaniana Transeau 1944 9 

transeauiana Randhawa 1938 19 

wuc/iangensis Li 1937 13 

16

CHAPTER FOUR 

THE GENUS HALLASIA ROSENVINGE 1924 

Among the incompletely known genera of the Zygnemataceae 

is Hallasia, proposed by Rosenvinge in 1924 better to classify the 

Zygnema reticulatiim described by Emma Hallas in 1895. The 

young vegetative cells resemble those of Zygnema in having two 

stellate chromatophores, but at the beginning of spore formation 

there may be an increase in the number of chromatophores up to 

seven. At the same time the cells may elongate, and as the cell 

contents contract toward the enlarged middle portion the cell 

cavity becomes filled with a cellulose-pectose colloid as in Zygne- 

mopsis. The aplanospores also resemble those of Zygnemopsis in 

being ellipsoid. When these aplanospores germinate, however, 

there may emerge one, two, or three sporelings. This Rosenvinge 

interprets as analogous to the germination of parthenospores in 

Cosmarium from which two sporelings result. He has suggested 

that the genus be placed among the Mesotaeniaceae or between 

that family and the Zygnemataceae. 

The species has previously been classified in Zyg?iema Hallas 

1895, in Debarya Transeau 1925, and in Zygnemopsis Transeau 

1934- 

Description of Species 

Hallasia reticulata Rosenvinge 1924. Rev. Algolog. 1, pp. 209-12. 

Hallas. Bot. Tidsskrift. 20, pp. 1-16. 1895 (as Zygnema 

reticulatiim^ 

Vegetative cells 18-20 /x x 35-1 00 /j- with 2 to 7 stellate chromato- 

phores in each cell; reproduction by aplanospores which are ellipsoid 

and up to ^^5^'' in diameter, 60 /.i long; median spore wall yellow, scro- 

biculate or irregularly reticulate; sporogenous cells lengthen up to 240 /a. 

At germination the contents of the spores may become divided into 

2 or 3 parts, from each of which a new filament develops. Sometimes 

only a single plant develops from a spore. (Pi. X, Figs. 1-9.) 

Denmark, Copenhagen. 

According to Rosenvinge the plant has not been found again at the 

site of the original collection. 

61

CHAPTER FIVE 

THE GENUS ZYGOGONIUM KtJTZING 1843 

The discovery and description of 14 species belonging to this 

genus have demonstrated the distinctive characteristics of the 

genus clearly and have justified its separation from the genus 

Zygnema. The small pillow^-shaped, or compressed-globular, 

chromatophores of the Zygogoniums are quite different from 

those of the Zygnemas. Under certain conditions these chroma- 

tophores may have a fevi^ short irregular appendages. In all species 

that have been described, howêver, the chromatophores occupy 

but a small fraction of the cell lumen. The small nucleus lies in 

the bridge between the chromatophores. 

The filaments are often branched, sometimes with horizontal 

branches and rhizoids in the soil surface, and with erect branches 

arising from them. A regular feature of the species growing on 

soil is the formation of thick, lamellate vegetative cell walls and 

akinetes. Indeed in situations which frequendy are dry, the filaments 

appear to be chains of akinetes. 

A common mode of reproduction is by aplanospores. These 

globose or cylindric-ovoid spores are formed within vegetative 

cell walls and are usually much smaller than the cells. Cyto- 

plasmic residues are present regularly in the cell lumen outside 

the spore, a feature not found in Zygnema. 

Reproduction by zygospores is less frequently seen. Conjuga- 

tion may be scalariform or lateral. In either event there are 

cytoplasmic residues left in the gametangia after the union of the 

gametes. All the 14 species that have been found reproducing 

sexually have the zygospores in sporangia formed by the greatly 

enlarged conjugating tubes. The two gametes unite directly in 

the tube, and a sporangium wall is immediately formed around 

them which separates them from the gametangia. The spores are 

discharged by the breaking of a distinct equatorial suture in the 

sporangium wall. 

All the species are amphibious and grow on wet, acid mineral 

63

64 

ZYGNEMATACEAE 

soils, rocks, and bogs. From there they are sometimes carried into 

streams and ditches by rains, and continue to grow in the water 

medium. 

In Zygogojiinm encetorum there is a strong tendency toward 

encystmcnt whenever habitat conditions change; this is true even 

of the gametes. The gametes may be walled off in the conjugating 

papillae before the solution of the wall between the papillae. Sub- 

sequently this wall may be dissolved and the gametes may unite. 

This was the mode of reproduction first seen and described by 

de Bary (1858). Subsequently normal reproduction was described 

by the Wests (1894), t>ut in 1918 Hodgetts found and described 

the reproduction by encysted gametes and insisted that this is 

the normal process. In 1933 Transeau published figures show- 

ing both modes of conjugation in the same pairs of filaments. 

Since none of the other species exhibits so-called secondary gametangia, 

these must be regarded as a peculiarity of Z. encetorum, 

and direct conjugation the normal procedure. 

The taxonomic characteristics of the genus Zygogonium may 

be summarized as follows: 

1. The species are terrestrial or amphibious on acid substrates. 

2. The filaments may become branched, sometimes with horizontal 

filaments on the soil and erect branches arising from them. 

3. Reproduction by akinetes and aplanospores is common. All the 

vegetative cells of some filaments may be changed to these structures. 

4. Reproduction by zygospores is apparently infrequent, and the 

zygospores are enclosed in a sporangium wall with an equatorial suture. 

5. Cytoplasmic residues are present in sporiferous and gametangial 

cells after spore formation. 

6. Cell walls and cell contents are often colored purple, and in terrestrial 

specimens the cell walls may become very thick, opaque, and 

yellow or brown. 

7. Accumulation of fat globules and starch in terrestrial specimens 

often obscures both the nucleus and the chromatophores. 

Key to the Species or ZYGOGONIUM 

I. With aplanospores only (zygospores unknown) 7 

1. With zygospores (sometimes aplanospores also) 2 


2. Median spore wall not smoodi, yellow to brown 4 

a- Median spore wall not smooth, blue 13. Z. indicum

ZYGOGONIUM 65 

3. Zygospores 15-26/U, x 20-36 ju,, sporangium 

suture indistinct i. Z. ericetorum 

3. Zygospores 13-17 m x 19-32 /x, sporangium 

suture prominent 2. Z. mirabile 

3. Zygospores 20-25 ju, x 18-25 /"-, sporangium 

with pectic wall 3- 2^- pectosum 

4. Zygospore median wall scrobiculate or punctate 5 

4. Zygospore median wall with pits, or marginal arched ridges 6 

5. Zygospores without distinct suture, median 

wall punctate 8. Z. punctatiim 

5. Zygospores without distinct suture. ... 9. Z.heydrichii 

5. Zygospores in sporangia having collars 

at both ends 14. Z. stephensiae 

5. Zygospores with distinct suture 10. Z.sinense 

6. Zygospores with scattered pits on 

median wall 1 1. Z. exuvidlijorme 

6. Zygospores with arching ribs on 

one side of suture 12. Z. plalôuntiosporum 

7. Spore walls probably smooth at maturity 8 

7. Spore walls not smooth when mature 9 

8. Diameter vegetative cells 10-14 /n, 

spores usually terminal 7. Z. kumaoense 


spores usually lateral 5. Z. talguppense 

9. Diameter vegetative cells 8-12/1, spore 

wall verrucose 4. Z. hansgirgii 

9. Diameter vegetative cells 16-20 ij^, spore 

wall scrobiculate 6. Z. capense 


I. Zygogonium ericetorum Kiitzing 1843. Phycologia Generalis, 

p. 446. 

Vegetative cells 12-33 m x io-ioom; chromatophores 2, stellate, pillow-form 

or indefinite, each with a central pyrenoid; filaments branched 

or unbranched; conjugation scalariform. Zygospores develop within 

definite sporangia formed by the conjugating tubes and cut oflf by a 

wall from the adjoining gametangia. Zygospores ovoid or ellipsoid, 

1 5-26 /J. X 20-36 /i, thick-walled, smooth; aplanospores globose or ovoid, 

occupying only a part of the original cell, 15-20 /x x 15-40 /x; wall 

smooth. (PL X, Figs. 10-16.) 

United States: Known to occur on acid soils, in ponds and peat bogs 

throughout the coastal plain from Maine to Mississippi, and in Ohio, Mich-


igan, GDlorado, and Utah. Also in Canada from western Ontario to Nova 

Scotia. Probably occurs throughout the northern and western provinces. 

Reported from all the continents. 

In terrestrial forms the cell sap may be purple, the cells somewhat 

smaller, and the walls thick, lamellate, and colored yellow or brown. In a 

collection from Kwangtung, China, the sporangia had a distinct outer pectic 

layer. 

2. Zygogonium mirabile (W. & G. S. West) Transeau 1933. Ohio 

Jour. Sci. 33, p. 158. Jour. Bot. 35, p. 39. 1897. 

Vegetative cells 12-13.5^ x 18-50^1; chromatophores 2, rather indis- 

tinct, each with a central pyrenoid; conjugation scalariform; zygospores 

formed in the enlarged conjugating tubes, which are walled ofT from 

the original cells; sporangium ovoid with prominent equatorial suture; 

spores filling the sporangium, ovoid, 13.5-17/i. x 19-32^1., smooth, but 

possibly immature in the one known collection. (PI. X, Figs. 17-19.) 

Portuguese West Africa, Huilla, April, i860 (Welwitsch Coll.). 

3. Zygogonium pectosum Taft 1944. Ohio Jour. Sci. 44, p. 238. 

Vegetative cells 9-12 /a x 12-108 /x, with 2 pillow-shaped chromatophores, 

sometimes elongate with flat ends; conjugation scalariform and 

lateral; zygospores formed in the greatly enlarged tubes; zygospores 

globose or subglobose (15-) 20-25/1 x 18-25/1, with a smooth, slate-blue 

wall; aplanospores cylindric-ovoid, 9-10/1 x 12-16/1, also slate-blue; 

sporangium outer wall a 2-4/1 layer of pectic compound. During conjugation 

the cells elongate and the walls change to pectic compounds 

and become greatly thickened. (PI. XI, Figs. 1-3.) 

1940. 

United States: Louisiana, near Hornbeck on wet seepage slopes, April, 

4. Zygogonium hansgirgii (Schmidle) Transeau 1933. Ohio 

Jour. Sci. 33, p. 159. Hedivigia. 39, p. 160. 1900 (as Zygnema 

hansgirgii). 

Vegetative cells 8-12/1 x 30-60/1, irregular; filaments short; conjugation 

unknown; aplanospore variable, ovoid, about the same diam- 

eter as the cells; median wall brown, with small angular protuberances 

(vcrrucose). (PI. XI, Figs. 4-6.) 

India, Igatpuri, 1895. 

5. Zygogonium talguppense Iyengar 1932. Rev. Algolog. 6, 

pp. 263-74. 

Filaments forming a thick felt on soil, increasing in width up- 

wards, often branching below; lower cells of the filament 12-16/1 x 

30-60 /t, the upper 17-20/1 x 30-90/1; conjugation unknown; apian-

ZYGOGONIUM 67 

ospores ellipsoid to subglobose, 12-26 /a x /ti, 13-34 developed in a lateral 

swelling and cut off from the parent cell by a curved wall; median 

spore wall smooth. (PI. XI, Figs. 7-8.) 

India, Mysore, on moist soil in plantation of Areca palm. 

6. Zygogonium capense (Hodgetts) Transeau 1933. Ohio Jour. 

Sci. 33, p. 159. Trans. Roy. Soc. S. Africa. 13, p. 66. 1925 

(as Zygnema capense). 

Vegetative cells 16-20/x x 20-60 /u,; conjugation unknown; aplan- 

ospores globose, 19-26/A in diameter, formed at the ends of the cells; 

median spore wall brown, scrobiculate, (PI. XI, Figs. 9-1 1.) 

South Africa, Stellenbosch, on damp soil. 

7. Zygogonium kumaoense Randhawa 1940. ]our. Indian Bot. 

Soc. 19, p. 247. 

Filaments forming a feltlike growth on clay soil, prostrate filaments 

of irregular cells with rhizoids, upright filaments of cyUndrical cells 

with elongated chromatophores and sometimes very long cells; vege- 

tative cells, 10-14 Ai X 20-140 m; reproduction by aplanospores, globose to 

subglobose, 12-16/J. x 15-24/'-, with transparent, smooth walls. (Pi. XI, 

Figs. 16-19.) 

India, Kumaon Himalayas, September, 1939. 

8. Zygogonium punctatum Taft 1944. Ohio Jour. Sci. 44, p. 238. 

Vegetative cells 9-12 /x x 30-45 /x, with 2 small, irregularly globose 

chromatophores; conjugation scalariform between gametangia that 

have elongated up to 115 as zygospores globose or subglobose, 18-27 a"- x 

21-32 /x, enclosed by a distinct sporangium wall; median spore wall 

yellow to yellow-brown, punctate. (PI. XI, Fig. 12.) 

1940. 

United States: Louisiana, De Ridder, on roadside seepage slopes, April, 

9. Zygogonium heydrichii (Schmidle) Transeau 1933. Ohio 

Jour. Sci. 33, p. 159. Flora. 83, p. 167. 1897 (as Zygnema 

heydrichii). 

Vegetative cells 14-20 ai x 25-80 a^, with 2 chromatophores, not stellate; 

conjugation lateral or scalariform; tubes arise from both gam- 

etangia and form sporangia walled off from the original cells; zygo- 

spores globose, ovoid, or kidney-shaped, 22-28 ai x 30-36 ai; median spore 

wall yellow, scrobiculate. (PI. XI, Figs. 13-15.) 

Australia, Sydney. 

10. Zygogonium sinense Jao 1935. Sinensia. 6, p, 571. 

Vegetative cells iG-iytJ- x 38-64 /j.; chromatophores 2, irregularly


globose bodies; reproduction by zygospores and parthenospores en- 

closed by sporangial walls; conjugation scalariform and lateral; zygospores 

compressed-globose or subglobose, 29-38/1. x 22-25/1; median 

spore wall yellow to brown, sharply scrobiculate on the faces, only 

slightly scrobiculate or striate near the prominent equatorial suture; 

parthenospores without prominent suture. (PI. XII, Figs. 1-5.) 

China, Nanking and Chungking. 

11. Zygogonium exuvielliforme Jao 1935. Amer. Jour. Bot. 22, 

p. 768. 

Vegetative cells 13-22^ x 48-105/i.; chromatophorcs 2; conjugation 

lateral and scalariform; spores formed in the greatly enlarged conjugating 

tubes; zygospores compressed-globose with distinct or prom- 

inent sutures, 35-42/1 x 38-54 /a in diameter; median wall yellow to 

brown, thick, lamellate, with scattered pits except near the equatorial 

suture. (PI. XII, Figs. 6-8.) 

South America, Colombia, Lake Macotama at 14,400 feet altitude. 

12. Zygogonium plakountiosporum Jao 1935. Amer. Jour. Bot. 

22, p. 767. 

Vegetative cells 16-22/i. x 30-155M, with 2 chromatophorcs close to 

the nucleus; conjugation lateral and scalariform; tubes greatly dis- 

tended containing the spores; zygospores compressed-globose with 

colorless outer wall; median wall brown, with equatorial suture more 

or less prominent, and with arching ridges forming a zone of pits on 

one side of the suture; spore dimensions 35-41 /^ x 40-68 ju. x 14-20 /i. 

(PI. XII, Figs. 9-11.) 

South America, Colombia, Lake Macotama at 14,400 feet altitude. 

This species is remarkable for its asymmetrically ornamented spores. 

13. Zygogonium indicum (Randhawa) Transeau. nom. nov. 

Proc. Indian Acad. Sci. 8, p. 140 (as Zygnema heydrichii 

var. indicum Randh.). 

Vegetative cells 18-22 /a x 50-90 /a, with 2 chromatophorcs near the 

nucleus; conjugation usually lateral, rarely scalariform; zygospores 

ovoid 22-27 /i. ^ î~S7/^' median wall greenish-blue to dark blue; scrobiculate 

with pits about 2/1 in diameter; parthenospores smaller and 

similar. 

India, Fyzabad, U.P., March 12, 1938. 

This species is placed in the genus Zygogonium because the spore is 

separated from the gametangia by a wall. In appearance it resembles 

Zygogonium heydrichii, a species having yellow spores.

ZYGOGONIUM 69 

14. Zygogonium stephensiae nom. nov. Trans. Amer. Micros. 

Soc. 53, p. 208, PI. 

iae Transeau). 

17, Fig. 4. 1934 (as Zygnema stephens- 

Vegetative cells 22-29 a

CHAPTER SIX 

THE GENUS PLEURODISCUS LAGERHEIM 1895 

This genus was established by Lagerheim to classify purple- 

colored vegetative filaments, the cells of which had two distinct 

disc-shaped chromatophores, one on either side of a central 

nucleus (P. purpureus). Skuja (1932) questioned the validity of 

the genus and suggested that the chromatophore is merely an 

expanded form of the Zygogonium chromatophore due to environmental 

conditions. In 1936 Tiffany described a species P. borinquenae 

from Puerto Rico, the first and only specimens found 

in a fruiting condition. The chromatophores certainly were disc- 

shaped and oriented at various angles to each other. The proc- 

esses of conjugation and spore formation resemble those of 

Zygogonium. 

Specimens resembling Lagerheim's figure, collected near 

Eaglesmere, Pennsylvania, and those collected by Randhawa in 

India, were associated with smaller vegetative filaments of Zygogonium; 

there were no intergradations. Environmental factors 

do not seem to account for the differences in chromatophores in 

these collections. When Zygogonium filaments are growing lux- 

uriantly, the pillow-shaped chromatophores are larger and there 

is a fringe of several stringlike or radial projections, very different 

from the smooth-edged disc, or saucer-shaped, bodies of Pleurodiscus. 

Further study of the algae growing in the drainage from 

wet acid rocks and soil will probably uncover additional species 

and clarify the status of this genus. 


Pleurodiscus borinquinae Tiffany 1936. Brittonia. 2, p. 169, 

Figs. 31-39- 

Vegetative cells 18-26 /a x 16-65 /a, pectic sheath sometimes thick; 

filaments either simple or branched and having rhizoids; zygospores 

ovoid to ellipsoid, within a sporangium partly formed by the tube 

papillae and partly by a collar between them; zygospores 22-32 /^ x 

26-32 ju. with a scrobiculate spore wall; pits 3 to 5 /a in diameter. (PI. XII, 

Figs. 12-15.) 

Puerto Rico, Palmar, January to March (Wille Coll.). 

71

CHAPTER SEVEN 

THE GENUS MOUGEOTIOPSIS PALLA 1894 

These algae have simple filaments, with vegetative cells one- 

half to four diameters long; each with a single quadrate, flat, or 

dished platelike axile chromatophore with a thickened and minutely 

granulate margin. The margin is sometimes inroUed, and 

pyrenoids are absent. Oil globules occur on the surface, and both 

starch granules and oil drops within the chromatophores. Reproduction 

is by short to long ovoid zygospores irregularly formed 

in the tube (isogamous) and extending into one or both gametangia, 

but not cut off from the gametangia by a wall. Only one 

species is known, from Europe and America. 

This genus has had an interesting history beginning with the 

description and figures published by Palla (1894). In 1898 W. & 

G. S. West claimed to have found the same alga with pyrenoids 

and placed it in Debarya. In 1899 Brand described a new genus 

from southern Bavaria which he called Mesogerrott. His descrip- 

tion emphasized the dished or partly cup-shaped forms of the 

chromatophore and the absence of pyrenoids. His figure exaggerates 

the curled edges of the chromatophores, as shown by an 

examination of Brand's own specimens from Munich, which are 

in my possession. Brand thought that his plant belonged among 

the Ulotrichaceae, but Wille (1911) placed it provisionally among 

the Zygnemataceae. Skuja reported the occurrence of Mesogerron 

in Latvia in 1928, and in 1929 showed that "Mesogerron" is 

merely the vegetative form of Mougeotiopsis. Although Czurda 

(1932) insisted that the only important structure upon which 

genera of the Zygnemataceae may be based is the chromatophore, 

he includes this genus among the species of Mougeotia in spite of 

the absence of pyrenoids, the presence of oil droplets, and the 

unique thick-edged chromatophore entirely unlike that of any of 

the known species of Mougeotia. It might be added further that 

the zygospores, with their relatively thick and highly refractive 

median walls with deep sharp-edged pits, are equally unique 

73

74 

ZYGNEMATACEAE 

among the Zygnemataceae. Skuja's figures are the only ones that 

accurately represent cither the vegetative or the reproductive 

structures. 


MouGEOTioPsis cALospoRA Palla 1894. Berichte deutsch. hot. 

Gesells. 12, p. 228. Skuja. Acta Horti Bot. Vnw. Lat- 

viensis. 1, p. 45, PI. 2, Figs. 19-26. 1929. 

Vegetative cells cylindric, io-18/x x lo-yoju. with plane end walls; 

I axial chromatophore with the nucleus beside it in the center of the 

cell; fertile cells similar or somewhat longer; conjugation scalariform; 

zygospores often irregularly placed and irregularly ovoid to quadrate- 

ovoid 16-2 v^ X iu.; 21-38 outer wall thin, transparent; median wall 

thick, deeply and sharply scrobiculate; pits 1.5-2.5 m in diameter, light 

yellow to brown in color. (PI. XII, Figs. 16-17.) 

United States: Wisconsin (Prescott Coll.); Michigan, Douglas Lake 

(Ackley Coll.). 

Southern Bavaria; Austria; Czechoslovakia; Latvia. 

In the American specimens I found conjugation occurring between 

filaments of all the various diameters so that it seems inadvisable to separate 

the smaller and larger forms as has been suggested by some authors.

CHAPTER RIGHT 

THE GENUS DEBARYA WITTROCK 1872 

Wittrock established the genus Debarya better to classify the 

Mougeotia glyptosperma, so lucidly described and figured by 

Anton de Bary in 1858. Since then several other species have been 

discovered wîth similar characteristics. The filaments are simple, 

made up of cells two to twenty diameters long with ribbonlike, or 

platelike, chromatophores with several distinct pyrenoids arranged 

either in a single row, or scattered. The nucleus is centrally 

located in the cell and attached to the side of the chromatophore. 

The Debaryas resemble the Mougeotias during the vegetative 

phase. 

They differ from the Mougeotias, however, during the repro- 

ductive phase. At the beginning of conjugation, or during aplan- 

ospore formation, the reproductive cells become filled with a cel- 

lulose colloid deposited as successive layers inside the cell walls. 

Moreover, there are no cytoplasmic residues left in the gametangia 

outside the spore walls. Conjugation is scalariform, and the gametes 

unite in the conjugating tubes (isogamous). Aplanospores, 

parthenospores, and akinetes have been observed in 2 of the 

species. 

The zygospores are compressed-spheroid, ovoid, or quadran- 

gular-ovoid. The spores of 4 of the species are distinctly tricari- 

nate, with an equatorial and two lateral keels. The median walls 

may be further ornamented with pits, radial ridges, and undu- 

lations. 

All the 6 species are exceedingly rare, but they have been col- 

lected in Europe, Asia, North America, and New Zealand; they 

are probably more widely distributed than is surmised at the 

present time. 

Several of the species that were formerly described as belong- 

ing to this genus have now been placed in the genera : Mougeotia, 

Mougeotiopsis, Zygnemopsis, and Hallasia. 

75

76 

ZYGNEMATACEAE 

Key to the Species of DEBARYA 

I. Zygospore median wall tricarinate 2 

1. Zygospore median wall quadrangular- 

ovoid 5. D. hardyi 

I. Zygospore median wall globose to 

polyhedric 6. D. polyedrica 

2. Polar surfaces with a distinct "hub" i. D.glyptosperma 

1. Polar surfaces without "hub" 3 

3. Diameter vegetative cells i8m or more 4. D.smithii 

3. Diameter vegetative cells less than i>S/x 4 

4. Polar surfaces obscurely radially 

striate 2. D. costata 

4. Polar surfaces obscurely pitted.... 3. D.ac^leyana 


1. Debarya glyptosperma (de Bary) Wittrock 1872. Bih. Kgl. 

Sve7isk, Veiensl{. Akad. Handl. 1, p. 35. 

Vegetative cells 10-15 ju, x 40-200 m, with a single, axile, flat, ribbon- 

like chromatophore with 8 to 12 pyrenoids; conjugation scalariform, 

tubes very long (up to 80 /a), at first slender and increasing in width 

until spore is mature; spores formed in the tubes, compressed-ellipsoid 

or broadly ellipsoid, 30-46 /x x 42-72 /it; median spore wall tricarinate, 

yellow, with an irregular polar ring of protuberances; radially and dis- 

tinctly corrugate between the "keels and hubs" when mature. (PI. XII, 

Figs. 18-19.) 

United States: Reported from New Hampshire, Minnesota, Florida. 

Europe, widely distributed from Wales to Russia and Spain. 

The variety "formosa" Transeau (1915) is an error. 

2. Debarya costata Randhawa 1938. Proc. hidiati Acad. Sci. 

8, p. 121, Fig. 2. 

Vegetative cells 7-11/J- x ioo-150/u, with a single axile ribbonlike 

chromatophore with 4 to 10 pyrenoids; conjugation scalariform with 

slender long tubes; zygospores, 36-44 ^ x 38-50/1, compressed-globose to 

ovoid, tricarinate with clearly defined ridges between the keels; the 

polar faces of the spores have no "hubs" as in D. glyptosperma but are 

obscurely and radially corrugate toward the margin. The color is bright 

yellow, and lateral keels are crinkly. (PI. XII, Figs. 22-23.) 

India, Fyzabad, U.P., December, 1936. 

The specimens sent me by Randhawa contain mature spores, and the 

above description is based in part on this material.

DEBARYA 77 

3. Debarya ackleyana Transeau 1944. Ohio Jour. Sci. 44, p. 244. 

Vegetative cells 12-15 /x ^ 90-140 /u, with a single ribbonlike axile 

chromatophore with about 8 pyrenoids; conjugation scalariform, tubes 

long and slender at first, later the median spore wall becomes rounded 

and the sporangium wall is perfectly distinct; zygospores golden yellow 

mostly compressed-globose, sometimes ovoid, /ia 50-54 x 52-65 /a; median 

wall tricarinate, the lateral keels finely ruffled and very distinct, with 

corresponding corrugations between the keels; the middle keel is thin, 

radially striate and up to 10 ju. wide; polar walls obscurely pitted and 

without "hub." (PL XII, Figs. 20-21.) 

United States: Michigan (Ackley Coll.); Massachusetts (Bullard Coll.). 

Named for Dr. Alma Ackley who collected the type specimens near 

Douglas Lake, Michigan. 

4. Debarya smithii Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 216. 

Vegetative cells 21-28 ju. x 68-140 m, with i axile ribbonlike chromatophore 

containing 2 to 4 pyrenoids; reproduction by zygospores, 

conjugation scalariform; at time of conjugation, the chromatophores 

lengthen as they pass into the sporangium and each may then contain 

from 10 to 20 pyrenoids; zygospores compressed-globose or ovoid, 

55-72 /A x 64-80^1; the median wall strongly tricarinate with projecting 

ruffled ridges; the lateral wall between the keels is striate; the polar 

faces are distinctly and irregularly pitted, sometimes also finely punc- 

tate. This is the most elaborately ornamented species in the genus, 

(PI. XII, Figs. 27-28.) 

United States: CaUfornia, Fresno (G. M. Smith Coll.). 

Named for Gilbert M. Smith, Stanford University, author of Freshwater 

Algae of the United States, Marine Algae of the Monterey Peninsula, 

and many other contributions to phycology. 

5. Debarya hardyi G. S. West 1909. Jour. Linn. Soc. of London 

Bat. 39, p. 51, PI. 2. 

Vegetative cells 6.5-8 /a x 57-1 20 m with i ribbonlike chromatophore 

containing from 2 to 4 pyrenoids; judging by West's figures the num- 

ber of pyrenoids increases during conjugation; conjugation scalariform; 

zygospores compressed-quadrangular, 22.5-27 /x on a side. As the spores 

were immature, further details are unknown. It is possible that this 

alga may, when fully known, be placed in Zygnemopsis. (Pi. XII, 

Figs. 29-30.) 

Australia, Victoria, Yan Yean Reservoir. 

6. Debarya polyedrica Skuja 1937. "Algae." Symbolae Sinicae. 

Pt. I, p. 84, PL 2, Figs. 3-8.

78 

ZYGNEMATACEAE 

Vegetative cells 8-i2/i x 50-200M, with 2 platelike chromatophores 

each containing i or 2 pyrenoids; reproduction by zygospores and 

aplanospores; conjugation scalariform; gametangia genuflexed and sep- 

arating after conjugation; zygospores globose to polyhedric-ovoid, 

26-33 /A in diameter, completely filling the tubes; outer spore wall thick 

lamellate; median spore wall golden yellow, smooth; inner spore wall 

moderately thick, hyaline, irregularly scrobiculate within; aplanospores 

obliquely rotund-fusiform, 24 ^t x 42-54/1. (PI. XII, Figs. 24-26.) 

China, northwestern Yunnan on sinter terraces at an altitude of 2,765 

meters, October 4, 1914.

CHAPTER NINE 

THE GENUS MOUGEOTIA C. A. AGARDH 1824 

Plants belonging to this genus were figured and described as 

early as 1803 by Vaucher in his Histoire des Conferees. Agardh, 

however, was the first to classify these plants in a way that clearly 

distinguished them from other "conjugates." During succeeding 

years of the nineteenth century there was much confusion about 

the nature of the group of cells now called the spore, sporangium, 

and the gametangia. Some authors interpreted the group of cells 

as the spore; others thought the gametangia and conjugating tube 

constituted a "carpogonium." When the gametangia became 

divided by the sporangium walls, the ends of the gametangia were 

looked upon as "sterile cells," since they are not empty but contain 

"cytoplasmic residues." Hence, many descriptions until those of 

very recent years contain the statement that the spore, or "fertile 

cell," is adjoined by two, three, or four "cells" instead of two, 

three, or four dead ends of the gametangia. Apparently, because 

of the "residues," many authors could not see the complete homology 

between these reproductive structures and those of Zygnema. 

Because of the emphasis placed on the reproductive structures, 

the position of the "fertile cell" relative to the remnants of the 

gametangia became the basis of several genera which have been 

discarded by most authors. These generic names are only of 

historic interest and are listed at the end of the section. Plants of 

this genus are generally simple filaments of cylindric cells. Rarely 

one celled or two celled branches occur, particularly near the bases 

of filaments where the latter are anchored by coiling around a 

support or are attached to some substrate by rhizoids. 

The vegetative cells are comparatively long, five to twenty 

diameters, with plane end walls that are thinnest at the center. 

Hence when the cells of a filament separate, the free ends are 

usually somewhat conical. Each cell has one or two axial, flat 

chromatophores extending the full length of young cells but 

79

8o ZYGNEMATACEAE 

occupying only a part of the axis of mature cells. The nucleus is 

near the center of the cell, placed on one side of the chromatophore 

in those species which have a single chromatophore. In 

species with two chromatophores, such as M. protia, the nucleus 

lies in the bridge between the chromatophores. Under natural 

conditions favoring active growth the chromatophores of M. 

capticina may be either ribbonlike or rodlike, and the cells may 

have purple cell sap in some filaments instead of the usual color- 

less solution. The pyrenoids in most species are arranged in a 

linear row; in a few they are scattered throughout the broad plate- 

like chromatophores. 

Of the 99 species here described, 92 usually reproduce by means 

of zygospores, and 7 by aplanospores. Of the 92 zygosporic species, 

25 also occasionally produce aplanospores either in the same 

filament with zygospores, or in separate aplanosporic filaments. 

Scalariform conjugation occurs in 86 species. Conjugation 

may be either scalariform or lateral in 4 species, and in only 2 is 

it regularly lateral. 

Almost all the species are isogamous; only 3 species are strictly 

anisogamous, and 2 others somewhat variable even in the same 

paired filaments. The distinction between parthenospores and 

aplanospores is not always easy to make. In many of the 25 species 

reproducing both by zygospores and aplanospores, the form 

and placement of the spores are somewhat different. In those 

species having aplanosporic filaments the distinction is more 

evident. These filaments are quite regularly zigzag with the 

spores at the angles, the first facing in one direction and the next 

in another direction. Hassall described such filaments in 1842, 

and figured an immature one in 1845 {M. notab'iUs). Wittrock 

(1878) also discussed this feature of aplanosporic filaments when 

he proposed the genus Gonatonema. Paul Petit (1880), the Wests 

(1902), and Czurda (1931) have suggested that these spores may 

result from internal division of a vegetative cell followed by 

lateral conjugation. This speculation still awaits cytological evi- 

dence. In the hundreds of developing aplanospores studied by 

me and my associates, not a single example of preliminary division 

of either the protoplast or the nucleus has been found. There is 

good reason to believe that rare instances of lateral conjugation 

may be found among the usually scalariform species of Mougeotia 

just as in Zygnema and Spirogyra. Such instances, however, can-

MOUGEOTIA 8i 

not be cited as proof that the aplanospores so commonly found 

among the Mougeotias are the result of lateral conjugation. 

Two unusual growth processes occur among several species of 

Mougeotia, of which M. genuflexa and M. reinschii are the commonest 

examples; these are adhesion and genuflexion. It is true 

that as new filaments appear in some permanent ponds, new 

adhesions and genuflexions may continue to develop for several 

successive months. Apparently cells coming in contact produce 

growth substances which cause pectinization of the walls in contact 

and increased growth of the wall at the point of contact. The 

first results in adhesion; the second in genuflexion. 

Genuflexion is not an early stage in conjugation that has been 

terminated before the development of tubes. There is no evidence 

that it has either an advantage or a purpose, although various 

authors have sought to find one. In one pond in which the process 

occurred throughout the growing season during several successive 

years, the interlocked filaments survived for a short time and then 

fragmented and went to the bottom. No zygospores were ever 

collected from this pond during the six years of observation. 

The steps in conjugation in the Mougeotias as in the other 

genera in this family are probably activated in the same manner 

as those observed by J. R. Raper in Achlya {Amer. Jour. Bot. 

[1939-40]), a fungus in which the succession of hormones seems 

to have been established clearly. 

Analogous changes occur in sexual reproduction though the 

cells are not necessarily in contact. The first visible changes are 

the growth of two papillae from nearby cells, until they meet, 

adhere, and the walls in contact are dissolved. Possibly other 

hormones lead to the movement of the protoplasts of both gam- 

etangia into the conjugating tube, which meanwhile has greatly 

enlarged, and growth has resulted in a form characteristic of the 

species. Then follows the union of gametes and the deposition 

of successive layers of the spore wall. 

With a few exceptions zygospores and aplanospores of Mou- 

geotia have only two walls—an outer chitinous wall variously 

colored and ornamented, and an inner transparent wall. In many 

species the spores are enclosed by a sporangium wall, in others 

the sporangium is merely a combination of gametangial and tube 

walls. In some species the outer layer of the sporangium wall 

changes to pectic compounds and forms a transparent layer 2 to


2^î in thickness. In a few species with quadrangular spores, 

pectose layers arc formed between the sporangium wall and the 

spore. Most species have yellow to brown spores; 8 species have 

blue spores. 

Only during the reproductive phases of the life cycle can 

species of Debarya and Temfiogametum be separated with cer- 

tainty from those of Moitgeotia. 

Many of the published figures of Mougeotias do not show 

cytoplasmic residues in the gametangia after union of the gam- 

etes, because they are of little or no significance in the identifica- 

tion of species. However, they are present in all species of the 

genus now known. 

The generic names formerly applied to certain species of 

Mougeotia include the following: Sphaerocarpus Hassall 1843; 

Mesocarpus Hassall 1845; Pleurocarpus Braun 1855; Staurospermum 

Braun 1855; Craterospermum Braun 1855; Plagiospermum 

Cleve 1868; Sphaerospermum Cleve 1868; Gonatojiema Wittrock 

1878. Czurda 1932 included among the Mougeotias certain species 

here classified in the genera: Debarya, Mougeotiopsis, and 

Temtiogametum. 

Key to the Species of MOUGEOTIA 

I. With zygospores (rarely aplanospores also present) 2 

I. With aplanospores (zygospores rare or unknown) 69 

2. Sporangium between 2 undivided gametangia 3 

2. Sporangium dividing i of the gametangia 45 

2. Sporangium dividing both gametangia 48 

3. Sporangia globose, subglobose, ovoid, ellipsoid or dolioform, 

longer axis parallel with the conjugating tube 4 

3. Sporangia cylindric-oblong with concave sides and rounded 

ends 35 

3. Sporangia with longer axes at right angles to the conjugating 

tubes 38 

4. Spore wall smooth 5 

4. Spore wall not smooth 22 

5. Diameter vegetative cells usually less than 24^4 6 

5. Diameter vegetative cells usually more than 24 /a 17 

6. Vegetative cells usually less than 12/i in diameter 7 

6. Vegetative cells usually between 12^ and 24A1 in diameter 11 

7. Spores globose 8 

7, Spores ellipsoid or ovoid, longer axis same as that of tube 10

7. Spores globose to ovoid, variable in 

position, some extending into and di- 

MOUGEOTIA 83 

viding one or both of the gametangia 5. M.calcarea 

8. Spores colorless with thick outer 

pectic layer 7. M. victoriensis 

8. Spores brown 9 

8. Spores blue 11. M. fêrguelensis 

9. Diameter spores 7-8 /u^, outer wall brown i. M. angusta 

9. Diameter spores 13-24 /x, outer wall 

brown 3- ^« parvula 

10. Spores ovoid, longer axis ii-i5iu... 2. M.tenuissima 

10. Spores asymmetric, ellipsoid or do- 

lioform, longer axis 30-42 /a, outer 

sporangium wall a thick pectic layer 4. M. tubijera 

10. Spores ellipsoid, longer axis 20-28 /i- 6. M.elltpsoidea 

II. Spores variable in position in the con- 

jugating tube or dividing one or both 

gametangia 5. M. calcarea 

II. Spores globose or subglobose 12 

II. Spores ovoid to quadrate-ovoid 16 

12. Spores blue, vegetative cells about 

i2iu. in diameter 11. M. \erguelensis 

12. Spores blue, vegetative cells about 

17-22 /A in diameter 12. M. maltae 

12. Spores brown or yellow 13 

13. Filaments mostly less than 20 /x in diameter 14 

13. Filaments mostly more than 20 yu, in diameter 15 

14. Spores globose, contained in the 

conjugating tubes 8. M. recurva 

14. Spores globose, extending into the 

gametangia 10. M. drouetii 

14. Spores globose, ovoid or ellipsoid. . 9. M. adnata 

14. Spores rhomboid, usually lateral 

conjugation i3- -^^ reinschii 

15. Diameter of spores about 30-40M 15. M.scalaris 

15. Diameter of spores about 40-45/x 14. M.sphaerocarpa 

15. Diameter of spores 47-52 /x 16. M. jogensis 

16. Spore diameter about 24-30 ju-, con- 

jugation mostly lateral i3- ^- reinschii 

16. Spores 36-40 /x X 40-55 jU, diameter 

vegetative cells 19-24 /x 14. M. sphaerocarpa

84 

ZYGNEMATACEAE 

17. Diameter vegetative cells 24-40/i 18 


18. Spores 30-48/1 in diameter 19 

18. Spores /i. 47-52 in diameter id. M. jogensis 

18. Spores 55-70/1 in diameter 21. M. macrospora 

19. Spores about 30-40/1 in diameter 20 

19. Spores ovoid about 40/1 x 50-59/1 18. M. ovalispora 

19. Spores about 40-50/1 in diameter 19. M. hirnii 

19. Spores about 45-55 M in diameter 17. M.ajricana 

20. Conjugation usually lateral 20. M. genuflexa 

20. Conjugation usually scalariform .. 15. M.scalaris 

21. Spores about 50/1 in diameter 22. M.subcrassa 

21. Spores about 65/1 in diameter 23. M. crassa 

22. Diameter vegetative cells less than 16/1 23 


23. Spores ovoid, 18-20/1 x 21-25/1, light 

yellow, punctate 24. A/, caelestis 

23. Spores compressed-ovoid, rarely sub- 

globose (about 30-36/1) 50. M. ovalis 

23. Spores globose to ovoid, brown (about 

22-32/1) 25. M. nummiiloides 

24. Chromatophores with pyrenoids in a single row 25 

24. Chromatophores with pyrenoids scattered 30 

25. Spores globose or subglobose 26 

25. Spores ovoid to ellipsoid 29 

26. Diameter of spores usually less than 32/1 (in No. 28, 

28-35/^) ; 27 

26. Diameter of spores 32/1 or more (in No. 28, 28-35/1) 28 

27. Spore wall reticulate 26. M. sinensis 

27. Spore wall coarsely punctate 29. A/, micropora 

27. Spore wall punctate 28. M. ornata 

28. Diameter spores 32-38/1 36. A/, globulispora 

28. Diameter spores 40-50/1 27. A/, megaspora 

29. Spore length 28-45/1, wall verrucose, 

outer wall thick 34- ^- lamellosa 

29. Spore length 40-50/1, wall verrucose, 

outer wall thin 35- ^- fnicro verrucosa 

29. Spore length 40-50/1, wall punctate... 37. M.pulchella 

29. Spore length 35-50/1, wall scrobiculate 38. M.laevis 

29. Spore length 50-70/1, wall areolate. . . . 30. M.areolata 

30. Spores globose to subglobose 31

MOUGEOTIA 85 

30. Spores ovoid 40-54/^ in length 34 

31. Diameter vegetative cells 17-24)". 32 

31. Diameter vegetative cells 32-38/11 33 

32. Diameter spores about ju., 30 wall 

wrinkled 33- ^- gotlandica 

32. Diameter spores 42-50 ji^, median 

wall scrobiculate 32. M. talyschensis 

33. Spore diameter about 39-46;",, rather 

densely punctate 40. M. daytonae 

33. Spore diameter 40-42^1, sparsely scro- 

biculate 41. M. handelii 

33. Spore diameter about 60-68 ju 42. M. sanjordiana 

34. Spores extending into the gam- 

etangia 31 • .^- sumatrana 

34. Spores wholly in the conjugating 

tube 39- ^^- robusta 

35. Vegetative cells less than 30 /^ in diameter, pyrenoids in single 

row 36 

35. Vegetative cells more than 30 /a in diameter, pyrenoids scattered 37 


spores 28-36 /A X 47-58 ju, 43- .^- oblongata 


spores 19-21 /A X 19-21 /a 45. M. angolensis 

36. Diameter vegetative cells 25-28 /i, 

spores 55-64 /i X 30-34 /m 48. M. opelousensis 

37. Diameter vegetative cells 35-40 /a 46. M. laetevirens 

37. Diameter vegetative cells 43-53 M 47. M. acadiana 

38. Outer sporangium wall a thick pectic layer 39 

38. Sporangia without pectic layer (possibly present when 

young) 43 

39. Spores blue, wall with scattered scro- 

biculations 98. M. cotopaxiensis 

39. Spores blue, finely punctate 55- -^^ cyanea 

39. Spores blue, coarsely punctate 56. M. atubulosa 

39. Spores colorless, smooth 51. M. pectosa 

39. Spores yellow, brown, or chestnut brown 40 

39. Spores metallic green gy. M. chlamydata 

40. Spores yellow to brown 41 

40. Spores dark chestnut brown 42 

41. Spore wall smooth 52. M. gelatinosa 

41. Spore wall punctate 29. M. micropora


41. Spore wall scrobiculate 5S. M. paw/iusâe 

41. Spore wall irregularly corrugate 54. M. oedogonioides 

42. Diameter vegetative cells 14-18/A. . 53. M.disjtincta 

42. Diameter vegetative cells 20-25/i... 59. M.seminoleana 

43. Diameter vegetative cells less than 16 /x 

43. Diameter vegetative cells 18-21 m, spores 

blue, punctate 55- ^- cyanea 

43. Diameter vegetative cells 18-21 /tt, spore 

wall shallow-scrobiculate, brown 57, M.operculata 

44. Spores 28-32 ju. X 12-14 )n, walls 

punctate 49. M. depressa 

44. Spores 29-38 M X 26-36 /x, walls 

coarsely punctate 50. A/, ovalis 

44. Spores 32-34 M in diameter, walls 

blue, scrobiculate 98. M. cotopaxiensis 

45. Spores globose, or 3 lobed filling the sporangium 46 

45. Spores variable in position, 30-50 yu. in 

length 5. M, calcarea 

45. Spores variable in position, cylindric, 

60-78 /A 44. M. varians 

46. Diameter vegetative cells less than 

14/U. 60. M. transeaui 

46. Diameter vegetative cells more than 14/". 47 

47. Vegetative cells between 14 and 20 /a in 

diameter 61. M. fioridana 

47. Vegetative cells between 21 and ju. 25 in 

diameter 62. M. poinciana 

48. All spore walls smooth (inwardly granulose in No, 69) . . 49 

48. Spore walls not smooth 61 



50. Spores compressed-globose, diam- 

eter vegetative cells 12-13/^1 gg. M. \wangsiensis 

50. Spores globose, diameter vegetative 

cells 7-9 /A 64. M. cheroI{eana 

50. Spores globose, diameter vegetative 

cells 4-5/^ 6^. M. caiwani 

50. Spores quadrate-ovoid, with or without processes 51 

51. Angles of zygospores rounded, undulate, or truncate 52 

51. Angles of zygospores retuse, margins concave 55 

51. Angles produced, extending into gametangia 56 

44

MOUGEOTIA 87 

52. Zygosporangia regularly dividing the gametangia 53 

52. Only some of the zygosporangia 

dividing the gametangia 5. M. calcarea 

53. Diameter vegetative cells 3-5-4-5M 74. M.elegantula 


54. Diameter vegetative cells 8-9 /a. ... 82. M. virescens 

54. Diameter vegetative cells 11-14/^.. 86. M.paludosa 

54. Diameter vegetative cells 9-1 /a... 96. M.subpalndosa 

55. Vegetative cells 3-5 i^ in diameter 73- ^- delicata 

55. Vegetative cells 6-8^1 in diameter 77. M. viridis 

56. Zygospore angles with rounded processes 37 

56. Zygospore angles retuse or truncate 58 

57. Spores regularly quadrate, processes 

short 66. M. corniculata 

57. Spores irregularly quadrate, processes 

long 68. M. uberosperma 

58. Spores with processes truncate.... 65. M.americana 

58. Spores with processes retuse 69. M. craterophora 

59. Zygospores concave-cylindric 44. M. varians 

59. Zygospores quadrate, quadrate-ovoid to globose 60 

60. Dimensions of spores less than ju, 30 88. M.jragilis 

60. Dimensions of spores greater than 

35/A 71. M. granulosa 

60. Dimensions of spores greater than 

50 ju. 72. M. capucina 

61. Spores concave-quadrate, wall minutely 

verrucosa 76. M. gracillima 

61. Spores quadrate, sides straight, concave or convex, wall mi- 

nutely to coarsely punctate 62 

62. Diameter vegetative cells usually less than 13 m 63 

62, Diameter vegetative cells usually more than 13 /a 68 

63. Vegetative cell diameter usually less than 8 /a 64 

63. Vegetative cell diameter 8-13 /a 67 

64. Diameter vegetative cells 4-5 z^, reproduces 

mostly by aplanospores . . 75. M.boodlei 

64. Diameter vegetative cells 5-8 (-9) /a 65 

65. Zygospores with angles rounded, bulg- 

ing into the gametangia 81. M. austriaca 

65. Zygospores with angles produced (£ 

65. Zygospores with angles retuse, not 

produced 80. M. tumidula


66. Zygospores colorless, finely punc- 

tate, with an outer ring thickening 

on the produced angles 78. M. prodiicta 

66. Zygospores yellow to yellow-brown, 

punctate Gy. M. thylespora 

67. Spore angles truncate, colorless, punc- 

tate 85, A/. qitaJrangulata 

67. Spore angles retuse, coarsely punctate, 

yellow 84. M, punctata 

67. Spore angles rounded, coarsely punc- 

tate, yellow-brown 81. M. austriaca 

67. Spores irregular quadrate-ovoid, only 

the inner wall punctate, outer wall yellow-brown, 

thick and smooth 79. A/. regelUi 

67. Spores tumid-quadrangular, coarsely 

punctate, colorless 83. A/, rotundangulata 

68. Zygospores ovoid-globose, 36-46 yn 

in diameter 87. A/, aspera 

68. Zygospores irregular quadrate, long 

rounded processes yo. M. irregularis 

68. Zygospores quadrangular-ovoid, in- 

wardly granulose 71. A/, granulosa 

REPRODUCTION USUALLY OR OCCASIONALLY BY 

APLANOSPORIC FILAMENTS 

69. Diameter vegetative cells less than 8/^1 70 

69. Diameter vegetative cells 8-15)". 74 

69. Diameter vegetative cells more than 15 /^ 78 

70. Aplanospores globose, diameter 

27-30 /A 90. A/, tropica 

70. Aplanospores globose, diameter 

18-20/i. 91. A/, fniamiana 

70. Aplanospores ellipsoid, length 25-32 /x 71 

71 . Spore wall smooth 72 

71. Spore wall minutely punctate 73 

72. Diameter vegetative cells 4-5 m.... 89. M.tencrrima 

72. Diameter vegetative cells 6-9^1. ... 92. A/, ventricosa 

73. Diameter vegetative cells 4-5 M, sporangium 

wall without pectic layer 75- ^- boodlei 

73. Diameter vegetative cells 6-8 m, pectic 

layer on sporangium wall 91. A/, miamiana

MOUGEOTIA 89 

74. Spore wall smooth 75 

74. Spore wall punctate 76 

75. Diameter vegetative cells 8-12 /a, spores 

gray-brown 95. M. rava 

75. Diameter vegetative cells 8-14 p., spores 

colorless 5. M. calcarea 

75. Diameter vegetative cells 5-9 /a, spores 

yellow 92. M. ventricosa 

76. Vegetative cells 8-12 jtt in diameter 77 

76. Vegetative cells 13-15 /x in diameter 94. M.mayori 

77. Sporangia asymmetric-ellipsoid 93. M.prona 

77. Sporangia globose 24. M. caelestis 

78. Diameter vegetative cells 14-19JU... 51. M.pectosa 

78. Diameter vegetative cells 19-24/"-. . 14. M.sphaerocarpa 

Aplanospores have been observed in scattered cells, or entire filaments 

of the following species that regularly reproduce by zygospores 

M. ajricana, M. americana, M. areolata, M. caelestis, M. calcarea, M. 

capucina, M. cyanea, M. elegantula, M. floridana, M. gracillima, M. 

laetevirens, M. nummuloides, M. parvula, M. pectosa, M. poinciana, 

M. producta, M. quadrangulata, M. recurva, M. seminoleana, M. 

sphaerocarpa, M. thylespora, M. transeaui, M. tumidula, M. ubero- 

sperma, M. viridis. 


1. MouGEOTiA ANGusTA (Hassall) Kirchner 1878. Kryptogamen- 

fiora Schlesien, p. 128. 

Vegetative cells 5-6;". x 30-95 /a; chromatophores with 4 pyrenoids 

in a row; conjugation scalariform; zygospores formed wholly in the 

conjugating tube, globose, about 7-8 /a in diameter; spore wall brown, 

smooth. (PL XIII, Fig. i.) 

United States: South Carolina. 

British Isles; Germany; Austria; Belgium; Bulgaria; Czechoslovakia; 

North Africa; Netherland Indies. 

2. MouGEOTiA TENUissiMA (dc Bary) Czurda 1932. Siisswasser- 

flora Mitteleuropa. 9, p. 66. 

Vegetative cells 5-6 ju. in diameter; conjugation scalariform; zygo- 

spores formed wholly in the conjugating tube, ovoid, 11-15M x 12-14 ja; 

spore wall brown, thick, smooth. (PI. XIII, Fig. 2.) 

Germany; France. 

3. MouGEOTiA PARVULA Hassall 1843. Ann. and Mag. Nat. Hist. 

11, p. 434.

90 

ZYGNEMATACEAE 

Vegetative cells 8-13 )u x 30-140 m; chromatophore usually occupy- 

ing two-thirds of the cell, with 4-8 pyrcnoids; conjugation scalariform; 

zygospores formed wholly in the conjugating tube, globose, 13-25 /a in 

diameter; spore wall brown, thick, smooth; aplanospores obliquely 

ovoid, 16-20M X 20-24/1. (PI. XIII, Figs. 3-5.) 

United States: Iowa to Massachusetts; south to Louisiana and Florida. 

Widely distributed in Europe; China; Japan; Brazil; Africa. 

4. MouGEOTiA TUBiFERA Tiffany 1934. Trans. Amer. Micros. Soc. 

53, p. 218. 

Vegetative cells 9-10^1 x 90-400/^; chromatophore with 4-12 pyre- 

noids in a single, more or less irregular, row; conjugation tubes usually 

greatly elongated ( 10-65 /i.), often spirally twisted and nearly as large 

as the filaments (7-9 /^ in diameter). Conjugation occurs through the 

lateral wall of the papillae as well as through the end. Zygospores 

asymmetrically ovoid, usually showing a greater bulge on one side than 

on the other, 27-30 /a x 33-45 a^, not including the outer sporangial pectic 

layer which is 6-12/1 in thickness; sporangium wall smooth, hyaline; 

spore wall colorless, thicker, smooth. It is not certain that the spores 

were fully mature. (PI. XIII, Figs. 6-9.) 

United States: Florida; North Carolina. 

5. MouGEOTiA CALCAREA(Cleve)Wittrock 1872. Bih.Kgl.SvensJ{ 

Veiensl{. A /{ad. Handl. 1, p. 40, PI. 2. 

Vegetative cells 8-1 4 /x x 40-280/1; chromatophores with 4-8 pyrcnoids 

in a single row; cells elongating, becoming geniculate before spore 

formation; conjugation scalariform; zygospores formed wholly in the 

conjugating tube or extending into one or both gametangia, globose, 

25-30 /t in diameter, or angular-globose, 22-28/1 x 30-50/1; spore wall 

smooth, colorless, or pale yellow; aplanospore globose, lateral to the 

sporogenous cell, 17-21 /a in diameter, or rarely trapezoid-ovoid, divid- 

ing the sporogenous cell, 15-20/1 x 20-28/1. (PI. XIII, Figs. 10-12.) 

North America, British Columbia to Greenland; Dakota to Texas and 

eastward to Newfoundland and Florida. 

Brazil; Europe; North Africa; southern Asia. 

The variety name "bicalyptrata" has been applied to specimens in 

which the thickness of the end walls of the sporangium is unusually great. 

In some collections the thick polar walls occur in Hlamcnts among spores 

with thin uniform walls. Collections may contain only aplanosporic or only 

zygosporic specimens, while others may contain both in mixture. In Borge's 

type material for M. sphaerospora I found 2 zygospores similar to those of 

M. calcarea; moreover, I found no aplanospores resembling those figured by 

Czurda from Central Tibet as M. sphaerospora. This figure may represent 

a new species but descriptive details are lacking.

MOUGEOTIA 91 

6. MouGEOTiA ELLiPsoiDEA (W. & G. S. Wcst) Czurda 1932. Siiss- 

wasserflora Mitteleuropa. 9, p. 66. 

Vegetative cells 9.5-1 1.5 

/x in diameter; conjugation scalariform; 

zygospores formed wholly in the conjugating tube, ellipsoid, 16-26 ij. x 

22-28 ju.; spore wall smooth, brown at maturity. (PI. XIII, Fig. 14.) 

Burma; Austria. 

7. MouGEOTiA vicTORiENSis G. S. Wcst 1909. Jour. Lifjfi. Soc. of 

London Bot. 39, p. 51. 

Vegetative cells ii-i2At x 1 00-160^1; chromatophores with 2-7 

(usually 5-6), pyrenoids in a single, more or less irregular row; con- 

jugation scalariform; zygospores formed wholly in the conjugating 

tube, globose, 2 1-24 /x in diameter; spore wall smooth. Surrounding the 

sporangium a layer of pectic material develops which extends even 

beyond the outer sides of the gametangia, 60-63^1 in diameter. (PI. XIII, 

Fig. 18.) 

Australia, Victoria. 

8. MouGEOTiA RECURVA (Hassall) de Toni 1889. Sylloge Algarum. 

1, p. 714. 

Vegetative cells 12-18/^ x 50-1 80 /a; chromatophores with 4-8 pyre- 

noids; conjugation scalariform; zygospores formed wholly in the con- 

jugating tube, globose, 22-33 /a ^^ diameter; spore wall brown, smooth; 

aplanospores globose, 24-30^1 in diameter, at the bends in geniculate 

cells, or cylindric-ovoid, 14-18/i x 28-34 /i., in straight cells. (PI. XIII, 

Fig- I3-) 

United States: Michigan; Florida. 

Maritime Provinces of Canada; British Isles; Germany; Australia; 

Puerto Rico; South America; northern India. 

In the collection from Florida the spores, although mature, were highly 

variable in dimensions. 

9. MouGEOTiA ADNATA Iyengar 1932. Rev. Algolog. 6, p. 270, 

Fig- 3- 

Vegetative cells 15-17 /^ x 1 80-240 ;u, enveloped by a sheath 6-8 /a 

thick; chromatophore platelike, with 4-10 pyrenoids in a row; conjuga- 

tion lateral and scalariform; zygospores formed in the enlarged con- 

jugating tube, which also develops an outer pectic layer; in lateral 

conjugation elUpsoid or rarely reniform, 26-32 ju. x 30-38 /i.; in scalar- 

iform conjugation globose or dolioform, 3 1-33 m x 35-37 /x; spore wall 

brown, smooth. (PI. XIII, Figs. 15-17.) 

India, Periyar, on wet rock slopes.

92 

ZYGNEMATACEAE 

10. MouGEOTiA DROUETii Transcau 1938. Amer. Jour. Bot. 25, 

p. 524, Fig. I. 

Vegetative cells 14-18 ju. x 72-1 80 m, with 4 to 8 pyrenoids in a single 

row; conjugation scalariform; zygospores globose in the enormously 

enlarged tube and extending into the gametangia, 32-37 /a x 33-42 /x; 

spore wall smooth, yellow-brown, obscured by the granular membranous 

residue left after conjugation. (PI. I, Fig. 10.) 

South America, Brazil, state of Ceara, Fortaleza (Drouet Coll.). 

11. MouGEOTiA KERGUELENSis Kricgcf 1941. Rabeuhorst's Krypt- 

ogamenflora. 13 (2), p. 134. 

Vegetative cells about i2ai x 48-96^; chromatophore with several 

pyrenoids in a single row; conjugation scalariform; zygospores in the 

conjugating tubes, sometimes extending slightly into the gametangia, 

about 27 /x in diameter; spore wall smooth, dark blue. (PI. XIV, Fig. i.) 

Kerguelen Islands, South Indian Ocean (Werth Coll.). 

12. MouGEOTiA MALTAE Skuja 1 926. Acta Horti Bot. Univ. Lat- 

viensis. 1, p. 109, Fig. i. 

Vegetative cells 17-22/Li x 60-1 20 (-200) i^; chromatophore nearly 

as long as the cell, with 4-8 pyrenoids in a single row; conjugation 

scalariform; zygospores formed wholly in the conjugating tube, glo- 

bose ( ^50-) 32-35 (-40) u in diameter; spore wall blue, smooth, surrounded 

by a gelatinous layer 4-6^1 in diameter. (PI. XIV, Fig. 2.) 

Latvia, Usma Lake. 

13. MouGEOTiA REiNscHii Tfanseau 1934. Trans. Amer. Micros. 

Sac. 53, p. 224. 

Vegetative cells 15-24^1. in diameter; chromatophore with 4-8 pyre- 

noids in a single row; conjugation lateral, very rarely scalariform; 

zygospores quadrately ovoid, 24-30 /a x 26-32 m; spore wall brown, 

smooth. (PI. XIV, Fig. 3.) 

United States: Illinois; Ohio. 

Germany; Poland; Czechoslovakia; lava. 

In a collection from Fayettevillc, Ohio, May 8, 1934, several spores 

resulting from scalariform conjugation were found among the hundreds 

resulting from lateral conjugation. Formerly classified as Mougeotia gracilis 

(Reinsch) Czurda. 

14. Mougeotia sphaerocarpa Wolle 1887. Freshwater Algae of 

the United States, p. 227, PI. 146, Figs. 1-2. 

Vegetative cells 19-24/i x 60-1 20 (-240) m; chromatophore platelike, 

with 4-16 pyrenoids in an irregular row; conjugation scalariform; 

zygospores formed in the greatly enlarged conjugating tubes and ex-

MOUGEOTIA 93 

tending somewhat into both gametangia, ovoid to subglobose, 36-40 m x 

40-55 Ai; spore wall brown, smooth; aplanospores ovoid to obliquely 

ovoid, 24-30 ju. X 35-50 /i. (PL XIV, Figs. 4-6.) 

United States: Generally distributed throughout. 

China, several provinces (Li and Jao); India. 

In some collections aplanosporic filaments are more abundant than 

conjugating filaments. 

15. MouGEOTiA scALARis Hassall 1842. Ann. and Mag. Nat. Hist. 

10, p. 45. 

Vegetative cells 20-34 /a x 40-1 80 /x; chromatophores with 4-10 pyrenoids 

in a single row; fertile cells straight or slightly curved; conjuga- 

tion scalariform; zygospores formed wholly in the conjugating tube, 

ovoid to globose, 30-38 (-40) 

smooth. (PL XIV, Figs. 7-8.) 

yu. in diameter; spore wall yellow-brown, 

United States: Generally distributed in the eastern half. 

Southern Ontario; widely reported from Europe; China; lapan; India; 

New Caledonia; Queensland. 

16. MouGEOTiA joGENSis Iyengar 1932. Rev. Algolog. 6, p. 268, 

Fig. 2. 

Vegetative cells 22-26 /a x 100-200 /x, with a pectic sheath 6-7 /a in 

thickness; chromatophores platelike with 4-8 pyrenoids in a single row; 

conjugation scalariform and lateral; zygospores formed in the greatly 

enlarged conjugating tubes and finally cut of5 from the adjoining gam- 

etangia by lamellate thickenings of the sporangium wall; zygospores 

globose to ellipsoid, 47-52 /a in diameter; spore wall brown, smooth. 

(PL XIV, Figs. 9-10.) 

India, Mysore. 

The tube primordia in lateral conjugation sometimes arise at some 

distance from the partition walls. 

17. MouGEOTiA AFRicANA (G. S. Wcst) Transcau 1944. Ohio Jour. 

Sci. 44, p. 244. 

Vegetative cells 24-28 /i x 44-200 /x; chromatophore with 4-16 pyrenoids 

in a single row; conjugation scalariform; zygospores in the 

greatly enlarged conjugating tubes and extending nearly or quite across 

the gametangia, globose to ovoid, /x 35-44 x 44-60^; spore wall brown, 

smooth ; walls of gametangia usually thickened by an apparent change 

to pectic compound, and superficially suggesting a Debarya, readily 

distinguished from the latter, however, by the absence of completely 

filled gametangia; aplanospores and parthenospores ovoid, 20-25^ x 

22-30 /A, formed near the middle of the sporogenous cells. (PL XIV, 

Figs. 11-12.)

94 

Philippine Islands; Africa. 

ZYGNEMATACEAE 

This species has been previously classified as Debarya ajricana G. S. 

West, and as M. sphaerocarpa var. varians Transcau. 

i8. MouGEOTiA ovALispORA KHcger 1941. Rabenhorst's Krypt- 

ogamenfiora. 13 (2), p. 134. 

Vegetative cells 37-40/1 x 8o-i2o/>; chromatophores with 8 to 10 

scattered pyrenoids; conjugation scalariform; zygospores in the con- 

jugating tubes, ovoid to ellipsoid, 39-41 

smooth, yellow-brown. (PI. XIV, Fig. 14.) 

Germany, Brandenburg, Griinrade. 

/^ x 51-59/^; spore wall thick, 

19. MouGEOTiA HiRNii Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 218. 

Vegetative cells 25-28/1. x 60-1 40 /i.; chromatophores with 4-8 pyre- 

noids in a row; conjugation scalariform; zygospores formed wholly in 

the conjugating tube, ovoid, 40-48 /x x 43-50 /x; spore wall yellow-brown, 

smooth. (PI. XIV, Fig. 13.) 

United States: Michigan (Ackley Coll.). 

Finland; China (McClure Coll.). 

Formerly classified as M. scalaris var. macrospora Him. 

20. MouGEOTiA GENUFLEXA (Dillwyn) C. A. Agardh 1824. Systema 


Vegetative cells 25-38 /a x 50-225/1, often geniculate and attached to 

other similar cells, forming extensive nets, sometimes with rhizoidal 

branches; conjugation lateral, less frequently scalariform; zygospores 

quadrately ovoid to globose, 30-40/1 in diameter; spore wall smooth, 

brown. (PI. XIV, Figs. 16-17.) 

United States: Minnesota and Wisconsin to Louisiana; eastward to 

Massachusetts and Florida. 

Generally distributed in Europe; China, Kiangsi; Manchuria; Morocco. 

21. MouGEOTiA MACROSPORA (Wollc) dc Toni 1889. Sylloge Algarum. 

1, p. 716. 

Vegetative cells about 30/i x 180-300/1; conjugation scalariform; 

zygospores formed in the conjugating tubes, globose, 55-70/1 in diam- 

eter; spore wall smooth. (PI. XIV, Fig. 15.) 

United States: Pennsylvania; New Hampshire. 

22. MouGEOTiA SUBCRASSA G. S. Wcst 1909. ]our. Linti. Soc. of 

London Bot. 39, p. 50. 

Vegetative cells 41.5-43/'- x 240-280/1; chromatophore with 15-24 

pyrenoids arranged irregularly; gamctangia straight or slightly curved;

MOUGEOTIA 95 

conjugation scalariform; zygospores formed in the conjugating tube, 

globose, 40-41^1 in diameter; spore wall smooth and indistinctly lam- 

ellate; sporangial wall thicker at the ends of the tube. (PI. XIV, Fig. 18.) 

Australia, Victoria. 

23. MouGEOTiA CRASSA (Wollc) dc Toni 1889. Sylloge Algarum, 

l,p.7i6. 

Vegetative cells about 50 /a x 200-500 /j.; conjugation scalariform; 

zygospores in the greatly enlarged conjugating tube, globose, about 65/^ 

in diameter; spore wall smooth. 

United States: Florida. 

24. MouGEOTiA cAELESTis Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 218. 

Vegetative cells about 7-9 m x 50-75 /a; chromatophore with 2-6 

pyrenoids, usually 4; conjugation scalariform; zygospores in the con- 

jugating tube, rarely extending slightly into the gametangia, ovoid to 

subglobose, 18-20^1 x 21-25/^; spore wall light yellow, punctate; repro- 

duction usually by aplanospores; aplanospores globose to subglobose, 

usually near the middle of the cell, either dividing it or wholly external, 

rarely terminal, 16-18/x in diameter; spore wall as in zygospores. (PI. 

XV, Fig. I.) 

United States: Oklahoma; Florida. 

Named for the collector Celeste Taft. 

25. MouGEOTiA NUMMULoiDEs (Hassall) dc Toni 1889. Sylloge 

Algarum. I, Ft. 2, p. 713. 

Vegetative cells 8-16 /x x 32-1 60 /a; chromatophores with 2-6 pyre- 

noids in a row; conjugation scalariform; zygospores in the conjugating 

tubes, globose to ovoid {i']-)22--p.{-T^'])ix in diameter; spore wall 

brown, scrobiculate; aplanospores ovoid, within the angled sporogenous 

cell. (PI. XV, Figs. 2-3.) 

United States: Iowa to Maine; North Carolina; Florida. 

British Isles to Finland and Bulgaria. 

Specimens collected from a fountain, Miami Beach, May 2, 1926, were 

fruiting abundantly and had many filaments with several-celled branches. 

26. MouGEOTiA SINENSIS Li 1933. Ohio Jour. Set. 33, p. 152. 

Vegetative cells 15-22 ju, x 100-132^1; chromatophore with 4-6 pyre- 

noids in a single row; conjugating cells slightly geniculate; conjugation 

scalariform; zygospores in the conjugating tube, ovoid to globose, 

25-31 

XV, Fig. 4.) 

ju- X 25-31 /J.; spore wall yellow-brown, angularly reticulate. (PI. 

China, Tinghai.

96 

ZYGNEMATACEAE 

27. MouGEOTiA MECAspoRA Wittrock 1 872. Bill. Kgl. SvensJ{ 

Vetensk,- Akad. Handl. 1 (i). 

Vegetative cells 17-21 

/x. x 170-380 /x; conjugation scalariform; zygo- 

spores in the conjugating tube, globose, 40-50/i, or ovoid, 41-44/i. x 

45-48/i; spore wall brown, irregularly scrobiculate. (PI. XV, Fig. 5.) 

United States: Florida, Daytona Cypress Swamp (Tiffany Coll.). 

Sweden. 

28. MouGEOTiA ORNATA Jao 1935. Sincnsiu. 6, p. 577, Figs. 34-35. 

Vegetative cells 16-22 )u. x 76-176 /x; chromatophores with 4-10, 

usually 6, pyrenoids in a single row; gametangia straight; conjugation 

scalariform; zygospores in the conjugating tubes, globose to subglobose, 

28-35 M '" diameter; spore wall thick, more or less regularly and dis- 

tinctly punctate, with a prominent, ridged suture; margin of ridge 

finely undulate; yellowish-brown at maturity. (PI. XV, Figs. 6-7.) 

China, Szechwan. Collection of C. C. Jao, Herbarium, University of 

Michigan, No. S587. 

29. MouGEOTiA MicROPORA Taft 1934. Trans. Amer. Micros. Soc. 

53, p. 218, Fig. 62. 

Vegetative cells 18-23/t x 60-160 /x; chromatophores with 4-6 pyre- 


tube, globose to ovoid, or rarely slightly compressed-ovoid, 26-36 m x 

26-30 /x; outer sporangium wall a pectic layer 5-12 /a in thickness; spore 

wall brown, distinctly punctate; pores .5-1 m in diameter. (PI. XV, 

Fig. 8.) 

United States: Oklahoma; Michigan; Florida. 

30. MouGEOTiA AREOLATA Traiiscau 1934. Trans. Amer. Micros. 

Soc. 53, p. 219, Figs. 47-49. 

Vegetative cells 17-26 /x x 90-400 /n; cross walls more refractive than 

lateral walls and slightly colligate; chromatophores with 4-10 pyrenoids 

in a row, occupying from two-thirds to one-fourth the cell length; con- 

jugation scalariform; zygospores in the conjugating tubes, dolioform, 

with the ends short or extended, 43-50^ x 50-70^1; wall frequently in 

3 layers, the outer a thin, yellow, minutely punctate membrane, the 

second a heavy, yellow areolate wall with a prominent equatorial ridge 

and suture, the innermost wall thin and hyaline; aplanospores asym- 

metrically ovoid, 27-33 /x X 55-66 /x, markings similar to those of the 

zygospores. (PI. XV, Figs. 9-1 1.) 

United States: Florida, Oveida Springs (O'Neil Coll.). 

31. MouGEOTiA suMATRANA Schmidle 1895. Hedwigia. 34, p. 297. 

Vegetative cells 20-24 /x ^ 80-220 /x; chromatophore with scattered

MOUGEOTIA 97 

pyrenoids; gametangia somewhat shorter and thicker walled than the 

vegetative cells; conjugation scalariform; zygospores formed in the 

enlarged conjugating tube and extending into the gametangia, ovoid, 

about 42;u. X iU.; 52 spore wall brown, "granulate." (PL XV, Fig. 12.) 

Sumatra. 

32. MouGEOTiA TALYscHENsis (Woronichin) Czurda 1932. Siiss- 

wasserflora Mitteleuropa. 9, p. 73. 

Vegetative cells 19-21 /a x 80-100 /x; conjugation scalariform; zygospores 

formed in the broad conjugating tube, globose, 42-50 /j- in diam- 

eter; spore wall yellow-brown, punctate. (PI. XV, Fig. 13.) 

Russia, Baku; Manchuria. 

33. MouGEOTiA GOTLANDicA (Clcve) WittFock 1 872. Bih. Kgl. 

Svensf{ Vetensl{. Akad. Handl. 1 (i). 

Vegetative cells about 17-24 ft x 75-1 50 ft; chromatophore with 

scattered pyrenoids; conjugation scalariform; zygospores in the conju- 

gating tubes, globose, about 30-34 ft in diameter; spore wall yellowbrown, 

wrinkled. (PI. XV, Fig. 14.) 

Sweden; Latvia; Estonia; Luxemburg; India (Randhawa Coll.); China 

(Li Coll.). 

34. MouGEOTiA LAMELLOSA Jao 1935. Sinensia. 6, p. 577. 

Vegetative cells 19-30 ft x 60-1 85 ft; chromatophore with 4-9 pyre- 


tube, elhpsoid, 24-32 ft x 28-45 ft; outer spore wall smooth, lamellose, 

thick, especially on the ends; spore wall yellow, verrucose. (PL XV, 

Figs. 18-19.) 

Coll.). 

China, Chungking, January, 1933; France, Falaise (Leo Lesquereux 

The collection from Falaise, France, must have been made about a 

hundred years ago, but the filaments and spores are in excellent condition. 

This material is a part of a collection purchased from Leo Lesquereux by 

the Philadelphia Academy of Sciences. Dr. Ruth Patrick identifies the hand- 

writing on the label as that of Brebisson. 

35. MouGEOTiA MicRovERRUcosA Krieger 1941. Rabenhorst's Kryptogamenfiora. 

13 (2), p. 155. 

Vegetative cells about 27fi x 70-108 ft; chromatophores with several 

pyrenoids in a single row; conjugation scalariform; zygospores filling 

the conjugating tubes, ovoid, 33-36 ft x 44-49 f^; spore wall irregularly 

verrucose; elevations about ift in diameter. (PL XV, Fig. 20.) 

Germany, Brandenburg, Trebnitz.

98 

ZYGNEMATACEAE 

36. MouGEOTiA GLOBULispoRA Jao 1935. Sifiefjsia. 6, p, 578. 

V'egetative cells 19-32 /x x 96-228^1; chromatophore with 10-12 pyrcnoids 

in a single row; conjugation scalariform; zygospores in the con- 

jugating tubes, globose to subglobose, ^2-38.4 /i x 32-35 m; spore wall 

yellow-brown at maturity, finely and closely scrobiculate. (PI. XV, 

Figs. 15-16.) 

China, Chungking, February, 1932, and January, 1933; Puerto Rico. 

37. MouGEOTiA PULCHELLA Wittrock 1871. Hcdwigia (1871), p. 88. 

Vegetative cells 24-29 /a x 48-1 50 ju.; chromatophores with 4-8 pyre- 


tubes, ovoid to ellipsoid, with ends more or less flattened, 28-35/1 x 

40-50 m; spore wall yellow-brown, punctate. (PI. XVI, Fig. i.) 

United States: Minnesota; Michigan; Indiana. 

Sweden; Latvia; Finland; Germany; China, Kiangsi. 

38. MouGEOTiA LAEvis (Kutzing) Archer 1866. Quart. Jour. 

Micros. Soc. 6, p. 272, and 7, PI. 8, Figs. 1-3. Kiitzing. 

Species A Igarurn, p. 447. 1849. 

Vegetative cells 20-36^ x 20-100 /j,; chromatophores with 2 to 4 

pyrenoids in a row; conjugation scalariform; zygospores ellipsoid to 

ovoid, 20-36 /A X 35-50/4; wall scrobiculate; pits about 3/^ in diameter, 

2-3/1 apart. (PI. XV, Fig. 17.) 

United States: Wisconsin (G. M. Smith Coll.). 

England and Finland to Poland; Yugoslavia; North Africa. 

39. MouGEOTiA ROBUSTA (dc Bary) Wittrock 1885. Wittrock and 

Nordstedt Algae Exsiccatae, No. 651. 

Vegetative cells 25-33/1 x 75-260 /(.; chromatophores with 10-20 

scattered pyrenoids; conjugation scalariform; zygospores in conjugating 

tubes, ovoid to subglobose, 35-41 

/i x 47-58/'; spore wall brown, scrobic- 

ulate; pits 1-1.6/A in diameter, scattered. (PI. XVI, Figs. 2-4.) 

United States: Iowa; Michigan; Illinois; eastward to Massachusetts and 

New lersey. 

Africa. 

France; Germany; Sweden; Finland; Latvia; Ceylon; Japan; North 

Filaments with chromatophores having V-shaped ends or divided all 

the way to the nucleus are not uncommon in some collections. These chromatophores 

have sometimes been described as "double," or as 2 separate 

chromatophores. 

40. MouGEOTiA DAYTONAE Transcau 1934. Trans. Amer. Micros. 

Soc. 53, p. 219, Fig. 55. 

Vegetative cells 32-36/i x 100-250/1; chromatophores with numcr-

MOUGEOTIA 99 

ous scattered pyrenoids; conjugation scalariform; zygospores in the 

conjugating tube, globose, 40-45 i^, in diameter, or subglobose, 39-42 /a x 

45-50 /x; spore wall yellow, coarsely and irregularly punctate; pits about 

i.5jU, in diameter and about the same distance apart. (In the specimens 

seen the wall is also irregularly contracted and reticulate-wrinkled.) 

(PI. XVI, Fig. 5.) 

United States: Florida, Daytona (Tiffany Coll.). 

41. MouGEOTiA HANDELii Skuja 1937. Symbolue Sinicae. 1, p. 83, 

Fig. II. 

Vegetative cells about 35/^ x 70-1 /u,; 75 chromatophore platelike, 

with 8-14 scattered pyrenoids; conjugation scalariform; zygospores 

globose, 40-42 /x in diameter; spore wall olive-brown, scrobiculate on the 

inner side. (PI. XVI, Fig. 6.) 

China, Yiinnanfu, altitude 5,800 feet, February 20, 1914. 

42. MouGEOTiA SANFORDIANA Tiffany 1934. Trans. Amer. Micros. 

Soc. 53, p. 219, Fig. 58. 

Vegetative cells 33-38 /x x 1 00-250 ai; chromatophores with numerous 

scattered pyrenoids; conjugation scalariform; zygospores in the 

conjugating tube, globose, 63-68 /x in diameter, or subglobose, 54-65 m x 

65-72 /a; spore wall yellow, scrobiculate; pits 2-3^11 in diameter and 

about the same distance apart. (PI. XVI, Fig. 7.) 

United States: Florida, Daytona (Tiffany Coll.). 

43. MouGEOTiA OBLONGATA Transeau 1934. Traits. Amer. Micros. 

Soc. 53, p. 219, Fig. 38. 

Vegetative cells 14-22)". x 80-200 )tx; chromatophore with 6-i2(-i6) 

pyrenoids in a single row; conjugation scalariform, often connecting 

several filaments; zygospores in the conjugating tubes, usually bilobate- 

ovoid, sometimes more cylindric with concave sides, 28-36 ju. x 47-58 /x; 

spore wall yellow, sometimes finely punctate. (PI. XVI, Fig. 8.) 

United States: Florida, Fort Myers (Tiffany Coll.). 

This species is the first of 6 species having cylindric spores with concave 

lateral walls. M. opelousensis has round pillbox-shaped spores and is the 

culmination of this series of spore forms. 

44. MouGEOTiA VARiANS (Wittrock) Czurda 1932. SUsswasserflora 

Mitteleuropa. 9, p. 79. 

Vegetative cells 25-27111; chloroplasts with numerous scattered pyre- 

noids; conjugation scalariform; zygospores in the conjugating tubes, 

extending into or across the gametangia, cylindric-ovoid, usually with 

concave sides, ends convex, 48-60 /x x 64-78 ju,; spore wall yellow-brown, 

smooth; sporangia adjoined by 2, 3, or 4 cell remnants. (PI. XVI, 

Fig. 12.)

100 

ZYGNEMATACEAE 

United States: Wisconsin (Prescott Coll.). 

Sweden; Finland; Holland; Czechoslovakia. 

45. MouGEOTiA ANGOLENSis W. & G. S. Wcst 1 897. Jour. Bot. 35, 

P-39- 

Vegetative cells 25-29 /x x 100-145 /x; chromatophores with 4-6 very 

small pyrenoids irregularly disposed; conjugation scalariform; zygo- 

spores in the conjugating tubes, short-cylindric with concave sides, 

19-21 

XVI, Fig. 16.) 

/x in diameter; wall smooth; gametangia slightly curved. (PI. 

Africa, Angola. 

West's drawing of the spore may be misleading. The polar ends should 

be visualized as circular. 

46. MouGEOTiA LAETEviRENS (Braun) Wittrock 1877. Wittrock 

and Nordstedt Algae Exsiccatae, No. 58. Bot. Notiser 

1877. p. 23. 

Vegetative cells 35-40 /x x 65-350^1; chromatophores with numerous 

scattered pyrenoids; conjugating cells geniculate; conjugation scalar- 

iform; zygospores in the conjugating tubes; outer wall short-cylindric, 

/Li 36-47 X 45-72;"., with concave sides; spore wall yellow-brown, smooth; 

aplanospores ovoid or obliquely ovoid. Spores quite variable in form. 

(Pl.XVI, Figs.9-11.) 

Florida. 

United States: Wisconsin and Indiana; eastward to Massachusetts and 

Europe; South America; southern Siberia; India; China; Australia. 

47. MouGEOTiA ACADiANA Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 224. 

Vegetative cells 43-54/^ x 100-400 û,; chromatophores with many 

scattered pyrenoids; conjugating cells geniculate; conjugation scalar- 

iform; zygospores in the greatly enlarged conjugating tubes, cylindric- 

ovoid, usually with concave sides, ends convex, 51-70 /x x 57-78 m; spore 

wall yellow, thick, smooth. Similar to M. laetevirens but larger in all 

dimensions. 

United States: Mississippi and Florida. 

Latvia (Skuja); Czechoslovakia (Czurda). 

Some of the records for M. laetevirens probably belong to this larger 

species which it closely resembles. 

48. MouGEOTiA oPELOusENSis Taft 1 944. OIlio Jour. Set. 44, p. 238. 

Vegetative cells 25-28 /x x 1 50-340 /x; chromatophores with 6-12 

pyrenoids in a single row; conjugation scalariform; zygospores short-

MOUGEOTIA loi 

cylindric, with concave ends and sides, formed in the tubes, 55-64 /^ x 

30-34 m; spore wall yellow punctate; punctations about .8 /a in diameter 

and evenly spaced over the entire wall. (PI. XVI, Figs. 13-15.) 

United States: Louisiana, Opelousas, 1938. 

49. MouGEOTiA DEPRESSA (Hassall) Wittrock 1880. SJândinaviens 

Vaxter. 4, p. 23. 

Vegetative cells 7-12/A x 35-144JU,; conjugation scalariform and lat- 

eral; zygospores in the conjugating tubes, compressed-ellipsoid with the 

longer axis parallel to the filaments, 28-32 /x x 12-14 /x; spore wall 

brown, punctate. (PI. XVII, Fig. i.) 

United States: Mississippi; Florida. 

British Isles; Germany; Sweden; Luxemburg; Switzerland. 

When the spores are immature there is a distinct pectic layer on the 

sporangium wall. 

50. MouGEOTiA ovALis (Hassall) Nordstedt 1886. Bot. Notiser 

1886. p. 136. 

Vegetative cells ii-i4iU, x iio-140/u; conjugation scalariform; zygo- 

spores in the conjugating tubes, compressed-ovoid to subglobose, 

29-38 /x x 26-36 /x; spore wall finely scrobiculate, brown. (PI. XVII, 

Figs. 2-3.) 

British Isles; Italy; Germany; Switzerland. 

It seems probable that specimens will be found with a pectic layer on 

the sporangium walls. 

51. MouGEOTiA PECTosA Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 220, Figs. 53-54. 

Vegetative cells 14.5-19,", x i:io-iôix\ chromatophores with 4-8 

pyrenoids in a single row; conjugation scalariform, but less frequent 

than reproduction by aplanospores; zygospores in the conjugating tubes 

enclosed in a 5-10 /a thick pectic sporangium wall, compressed-globose, 

26-29 /x ^ 20-22 A*; spore wall colorless, smooth; aplanospores globose to 

compressed-globose, formed partly within or largely outside the mother 

cells, 18-21 /x in diameter, when formed outside the mother cell covered 

with a pectic layer. Spores may not have been fully mature. (PI. XVII, 

Figs. 4-6.) 

United States: Florida (Tiflfany Coll.). 

52. MouGEOTiA GELATiNosA Wittrock 1 889. Wittfock and Nord- 

stedt Algae Exsiccatae, No. 957. 

Vegetative cells i2-i8f(. x 1 20-1 80 /x; chromatophores with 3-6 pyrenoids 

in a single row; conjugation scalariform; zygospores in the con- 

jugating tubes, compressed-ovoid, 38-47 ju- x 28-39 /x, ^^^ including the


outer pectic layer, which may be 7-10/i in thickness; spore wall brown, 

smooth. (PI. XVI, Fig. 17.) 

British Isles; Sweden; Finland; Latvia; Spain. 

53. MouGEOTiA DisjuNCTA Tfanscau 1934. Trans. Amer. Micros. 

Soc. 53, p. 222, Figs. 50-51. 

Vêgetative cells 14-18^ x 50-200^; chromatophore with 2-8 pyre- 

noids in a line; conjugation scalariform; zygospores in the conjugat- 

ing tubes, compressed-globose, 24-32 m x 21-28 m; sporangium wall 

changing during maturity to pectic substance and becoming as much 

as 25 iu, in thickness and pushing the 2 gametangia apart, but supporting 

the zygospore within; spore wall chestnut brown, punctate, suture 

prominent. (PI. XVII, Figs. 7-8.) 

United States: Florida, Fort Myers (Tiffany Coll.); China, Hunan 

(lao 1940) listed as A/, gelatinosa. 

54. MouGEOTiA oEDOGONioiDES Czufda 1931. Bcih. Bot. Zentralbl. 

48, p. 286. 

Vegetative cells 16-18 /a in diameter, with 1-2 platelike chromatophores, 

each with 2-3 pyrenoids; conjugation scalariform between 

geniculate cells, lateral by the solution of the cross wall and the development 

of a conjugating tube between the ends of the gametangia; 

subsequently, in both cases, following the union of the gametes, the 

sporangium wall changes to a thick pectic layer, 8-20 a*^ in width; the 

gametangial wall at the point of union with the sporangium becomes 

modified, suggesting the ring scars of Oedogonium cells; zygospores 

globose or compressed-globose, 41-50/^1 x 40-41 

/a; outer wall thick, color- 

less, smooth; spore wall yellow, thick, and irregularly corrugate, with 

a distinct equatorial suture. (PI. XVII, Figs. 9-10.) 

Asia, Tibet. 

55. MouGEOTiA CYANEA Transcau 1926. Ohio Jour. Set. 26, p. 321. 

Vegetative cells (i4-)i6-i8(-2o))u. x 160-200 ;ia; chromatophore 

occupying one-third to one-half of the cell, with 4-10 pyrenoids in a 

row; conjugation scalariform; zygospores in the conjugating tubes, 

compressed-spherical, 38-48^11 x 30-40 /a, with the long axis parallel to 

the filaments; spore wall blue, finely punctate; aplanospores spheroidal, 

laterally placed in the sporogenous cell, 30-32)", in diameter; both kinds 

of spores surrounded at maturity with a transparent pectic layer, 4-8 /i 

thick, which may disappear in preserved specimens. (PI. XVII, Figs. 

15-17-) 

United States: Michigan and Ohio to Texas and Florida.

MOUGEOTIA 103 

56. MouGEOTiA ATUBULOSA Kricgcr 1941. Rabenhorst's KryptogamenfJora. 

13 (2), p. 168. 

Vegetative cells 19-21 /a x 100-140/^; chromatophores with several 

pyrenoids in a row; conjugation scalariform; zygospores compressed- 

ovoid, 25-27^1/, X 20-21 ju., with the longer axis parallel with the filaments, 

wholly within the conjugating tubes; at maturity the tube wall becomes 

a pectic wall 8-10 ^t in thickness; spore wall blue, coarsely punctate; 

pits about .5 /A in diameter, 1-1.5A1 apart. (PI. XVII, Figs. 13-14.) 

Java, Dieng Plateau (B. Rensch Coll.). 

57. MouGEOTiA OPERCULATA Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 220, Fig. 52. 

Vegetative cells 18-21 /a x 60-285/^; chromatophores with 4-8 pyre- 

noids, usually 4; conjugation scalariform; zygospores in the conjugating 

tubes, compressed-spheroid, 27-30/^ x 21-27 jU., with a prominent equa- 

torial ridge and suture on the wall; spore wall pale yellow, shallow- 

scrobiculate. (PI. XVII, Figs. 11-12.) 

United States: Oklahoma; Mississippi; Florida. 

58. MouGEOTiA PAWHUSKAE Taft 1934. TruHS. Amer. Micros. Soc. 

53, p. 220. 

Vegetative cells i8-22iu x 90-170/1,; chloroplasts with 6-8 pyrenoids 

in a row; conjugation scalariform; zygospores in the conjugating tubes, 

compressed-globose, 34-40 /a x 25-32^1, with the longer axis at right 

angles to the tubes, surrounded by a pectic layer 4-16/1 in thickness; 

spore wall yellow to yellow-brown, scrobiculate, with a distinct equa- 

torial suture. (PI. XVII, Figs. 24-25.) 

United States: Oklahoma, Pawhuska, April 25, 1932. 

59. MouGEOTiA SEMINOLEANA Tiffany 1934. Trans. Amer. Micros. 

Soc. 53, p. 220, Fig. 40. 

Vegetative cells 20-25 /t x 70-200 /t; chromatophores with 4-12 pyre- 


tubes, compressed-globose, 32-47 /x x 25-36/1; outer sporangium wall a 

pectic layer 2-4 /a in thickness, absent from most of the mature spores; 

spore wall brown to dark chestnut brown, coarsely punctate, suture 

sometimes prominent, sometimes scarcely visible; aplanospores smaller, 

20-22/1 X 25-29/1, usually outside the mother cell, otherwise similar to 

the zygospores. (PI. XVII, Fig. 22.) 

United States: Florida, Fort Myers; Texas, Fredericksburg (Taft Coll.). 

The last of the series with compressed-globose spores, which begins 

with M. depressa Number 49.

104 

ZYGNEMATACEAE 

60. MoucEOTiA TRANSEAui Colliiis 1912. Tiifls College Studies. 

Sci. Ser. 3, p. 77. Wittrock. Bih. Kgl. Svensk, Vetens}{. 

Akad. Handl. 1, p. 39. 1872 (as M. tenuis). 

Vegetative cells 9-13 /^ x 50-150 ja; chromatophore with 4-8 pyre- 

noids in a single row; conjugation scalariform; zygospores globose to 

triangular-ovoid, 20-30 /x x 26-36//., occupying the middle portion of the 

receptive gametangium and the tube; spore wall yelknv, smooth; aplan- 

ospores obliquely ovoid, 12-20/x x 20-32 /x, formed at the middle of a 

straight or slightly angled cell which may be as long as the gametangium 

or longer. (PI. XVII, Figs. 19-20.) 

United States: Not uncommon from Oklahoma eastward to Massa- 

chusetts and Florida. 

England; Sweden; India. 

The first of a series of 3 species in which the sporangium divides one of 

the gametangia but not the other. In many collections of these species there 

are filaments in which only part of the cells conjugate; the others form 

aplanospores. Other collections contain only aplansporic filaments. Recently 

Krieger has listed this species as M. abnorme Kisselev 1927. The figure in 

Kisselev's publication of 1927 is probably of some other species, since the 

first structures formed after conjugation are the 3 sporangial walls, and this 

figure has no sporangial walls. The name M. tenuis Wittrock 1872 was 

preoccupied by M. tenuis Kiitzing 1849, which proved to be a synonym of 

M. scalaris Hassall 1842. 

61. MouGEOTiA FLORiDANA Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 224. 

Vegetative cells 14-20/x x 60-200 /a; chromatophores with 6-8 pyrc- 

noids in a single row; conjugation scalariform; zygospores occupying 

the middle of the receptive gametangia and the tubes, globose to trian- 

gular-ovoid, i". 30-40 X 36-48 /a; spore wall yellow, smooth; aplanospores 

obliquely ovoid, 18-24 /x x 30-45 m, occupying the middle part of the 

cell; spore wall yellow, smooth. 

Florida. 

United States: Oklahoma and Texas eastward to Pennsylvania and 

Northern India (Randhawa Coll.). 

This species was collected by WoUe at Bethlehem, Pennsylvania, and 

named M. tenuis (Cleve) Wittrock var. minor. 

62. MouGEOTiA poiNciANA Transcau 1934. Trans. Amer. Micros. 

Soc. 53, p. 224, Figs. 45-46. 

Vegetative cells 21-25 ju, x 100-200 /it; chromatophores with 6-10 

pyrenoids in a single row; conjugation scalariform; zygospores occupy- 

ing the middle portion of the receptive gametangia and the tubes, tri- 

angular-ovoid to globose, 36-44M X 35-51 /t; spore wall yellow, smooth;

MOUGEOTIA 105 

aplanospores occupying the middle part of the cell; obliquely ovoid, 

/J. 24-30 X 32-48 Ai. (PI. XVII, Fig. 21.) 

United States: Florida, Daytona (Tiifany Coll.). 

In Florida the 3 foregoing species were all found in the same pond. In 

none of the specimens studied was interspecific conjugation observed. 

63. MouGEOTiA CAiMANi Transcau 1938. Amer. Jour. Bot. 25, 

p. 525, Fig. 2. 

Vegetative cells 4-5 m x 60-100 /x; chromatophores with 2-8 pyre- 

noids in a single row; conjugation scalariform; zygospores dividing 

both gametangia, subglobose, 20-25 ft ^^ diameter, surrounded by a thin 

pectic layer. Zygospores seen were smooth and colorless. They may not 

have been mature, but the dimensions of the filaments and the zygospores 

distinguish it clearly from all described species. (PI. XVII, 

Fig. 18.) 

Haiti, Trou Caiman (R. M. Bond Coll.). 

After conjugation the filaments form a tangled meshwork, since they 

bend in all directions during conjugation. 

64. MouGEOTiA CHEROKEANA Taft 1934. Trutis. Atuer. Micros. Soc. 

53, p. 222, Fig. 39. 

Vegetative cells 7-9 m x 90-120 /a; chromatophores with 2-6 pyre- 

noids in a single row; conjugation scalariform; zygospores filUng the 

tube and dividing both gametangia, globose, rarely subglobose, 21-25 /a 

in diameter, surrounded by an outer pectic layer 4-6/i in thickness; 

spore wall yellow to brownish-yellow, smooth. (PI. XVII, Fig. 23.) 

United States: Oklahoma, Wichita Mountains, April 29, 1932. 

65. MouGEOTiA AMERICANA Transeau 1918. Tech. Pub., No. 9. 

New York State College of Forestry, p. 237. 

Vegetative cells /«• 4-5 x 40-120 /x; chromatophores with 4-10 pyre- 

noids in a single row; conjugating cells slightly or strongly geniculate; 

zygospores dividing both gametangia, irregularly quadrate with concave 

or convex sides; angles produced and truncate, the space between 

the zygospore and the sporangium walls being filled with pectic ma- 

terial; spores 1 3-24 /i X 18-32/x; wall colorless, smooth, transparent; 

aplanospores obliquely elliptical, ends truncate at the middle of very 

long genuflexed vegetative cells, 10-14 /a ^ 20-26 /x. (PI. XVIII, Figs. 1-3.) 

United States: Michigan; New York; Florida. 

66. MouGEOTiA coRNicuLATA Hansgirg 1886. Oesterr. Bot. 

Zeitschr., No. 10. 

Vegetative cells 5-7 ft x 30-1 80 ft; conjugation scalariform; sporangia 

dividing both gametangia; zygospores quadrately ovoid, ft 22-26 x

io6 

ZYGNEMATACEAE 

22-26 /i.; spore wall yellow-brown, smooth, thickened, forming rounded 

processes at the angles. (PI. XVIII, Figs. 4-5.) 

From France to Czechoslovakia, and North Africa. 

The figure published by Hansgirg is incorrect in that chromatophorcs 

were drawn in the unoccupied halves of the gametangia. 

67. MouGEOTiA THYLESPORA Skuja 1929. Actu Horti Bot. Univ. 

Latviensis. 4, p. 48. 

Vegetative cells 5-8 yu, x 25-80 /x; chromatophore with 4-8 pyrenoids 

in a single row; conjugating cells geniculate; conjugation scalariform; 

sporangia dividing both gametangia; zygospores cjuadrangular with 

angles produced and truncate, 16-22/i. x 20-32 /x; spore wall yellowbrown, 

scrobiculate, with tumid sides and rounded projecting corners; 

aplanospores oblique-ellipsoid, i8-25At x 28.8-39.6/i. (PI. XVIII, Figs. 

6-8.) 

United States: Florida (Tiffany Coll.). 

Estonia. 

68. MoucEOTiA UBERospERMA W. & G. S. West 1897. ]our. Bot. 35, 

P-37- 

Vegetative cells 6-8 /i x 24-64 /x; conjugation scalariform; zygosporangium 

dividing both gametangia; zygospores angular-globose 

(4-6 angles), wall very thick and lamellate, smooth and colorless, with 

corners extended into 4 solid, unequal processes which project into the 

gametangia; zygospores 21-27 /u. in diameter, processes 3-1 /x 8 long; 

aplanospores 20 /-i x 30/x with 2 processes. (PI. XVIII, Figs. 9-10.) 

Africa, Angola and Kentani. 

69. MoUGEOTIA CRATEROPHORA Bohlifl I9OI. Blh. Kgl. SvCtlsJ^ 

Vetensk,. A /{ad. Handl. 27, p. 50. 

Vegetative cells 7-9M in diameter (8-14 diameters long); conjuga- 

tion scalariform; zygospores in the conjugating tubes, or dividing one, 

or both, gametangia; zygospores globose to ovoid, i8-22/i x 24-28 /t, 

with 2 to 4 crateriform or retuse processes; spore wall brown, smooth. 

(PI. XVIII, Figs. 11-14.) 

Azores. 

70. MoUGEOTIA IRREGULARIS W. & G. S. WcSt 1897. JoHV. Bot. 

35, p. 38. 

Vegetative cells 1 3.5-1 5 A^ x 70-90)11; conjugation scalariform; conjugating 

cells more or less recurved; sporangium dividing both gametangia; 

zygospores irregularly quadrate to trapezoid with concave 

sides and thick walls, 38-63^^ x 42-48/11 including the processes, angles

MOUGEOTIA 107 

with hornlike processes of varying length with rounded ends; spore 

wall thick, yellow to yellow-brown, punctate. (PI. XVIII, Figs. 15-16.) 


71. MouGEOTiA GRANULOSA Transeau 1938. Amer. Jour. Bot. 25, 

p. 525. 

Vegetative cells 14.4-18JU. x i40-i8o(-32o)iu. with 4 to 8 pyrenoids 

in a row; conjugation scalariform; sporangium wall thick, transparent, 

dividing both gametangia, varying from broadly ovoid to quadran- 

gular-ovoid; spores 36-47 A*' X 42-52 â; walls yellow to brown, rarely 

smooth, mostly granulose when mature, either apparently single or 

distinctly double—both layers granulose when separated. (PL XVIII, 

Figs. 18-20.) 

South Africa, Cape Town, Cape Flats (E. Stephens Coll.). 

72. MouGEOTiA CAPUCINA (Bory) Agardh 1824. Systema Algarum, 

p. 84. 

Vegetative cells 14-21 ju x 70-280 (-340) /t, usually violet colored; i 

or 2 chromatophores either rod-shaped occupying one-third to one- 

fourth of the cell with 4-8 pyrenoids, or ribbonlike occupying threefourths 

of the length of the cell with 12-16 ju, pyrenoids in a single row; 

conjugation scalariform; the first sporangium walls are formed at a 

distance (5-52 ;"•) from the zygospore, the intervening space filled with 

pectic compounds; sporangium divides both gametangia; zygospores 

irregularly quadrangular with concave sides, 50-70/4 x 60-100 /x; spore 

wall violet to brown, thick especially at the angles, smooth; aplan- 

ospores not uncommon, 20-36 /a x 45-70 (-80) /a, with more or less pro- 

duced ends. (PI. XVIII, Figs. 26-31.) 

United States: Wisconsin; Michigan; New York; North Carolina; 

Alabama; Florida. 

Widely distributed in Europe; Central Africa; northern South America; 

Hawaii; New Zealand. 

In some collections there are double spores that are the result of division 

of gametes just prior to conjugation. If conjugation fails in one or both 

pairs of gametes there may be one or more parthenospores instead of 2 

zygospores. At Tupper Lake, in the Adirondacks, September, 1936, a 

specimen was found with a mature zygospore formed by scalariform conju- 

gation between 2 adjacent cells of a filament. (PI. XVIII, Fig. 31.) 

73. MouGEOTiA DELiCATA Beck 1926. Archiv f. Protist. 55, p. 179, 

Fig. 17. 

Vegetative cells about 3.5 ju. in diameter; conjugation scalariform; 

sporangia dividing both gametangia; zygospores cruciate-quadrate,

io8 

ZYGNEMATACEAE 

with concave sides, angles with hornUke processes; spores about 28/x 

on a side. (PI. XVIII, Fig. 17.) 

Austria, Karnten. 

74. MouGEOTiA ELEGANTULA Wittrock 1 872. Om Gotland och 

Oelands Sot. Alg., p. 40. 

Vegetative cells 3.5-5 M x 50-1 35 /a; chromatophore with 4-8 pyre- 

noids in a row; conjugating cells geniculate; conjugation scalar iform; 

sporangium dividing both gametangia; zygospores cruciate-quadrate, 

1 8-24 /J. X 18-24/', ^^^^^ rounded corners; spore wall hyaline, smooth; 

aplanospores ellipsoid, 6-9/1 x 20-24/1, otherwise similar to the zygo- 

spores. (PI. XVIII, Figs. 21-22.) 

United States: Wisconsin; Iowa; Texas eastward to Massachusetts. 

Widely distributed in Europe; China, Yunnan; West Indies. 

At Twin Lakes, Michigan, a specimen was collected in which a zygo- 

spore had been formed by scalariform conjugation between 2 cells of the 

same filament, which had been bent into a loop. 

75. MouGEOTiA BooDLEi (W. & G. S. Wcst) ColHns 1912. Tufts 

College Studies. 3 (2), p. 76. 

Vegetative cells 4-5.5 M x 25-225/1; chromatophore .5-8 of the 

length of the cell, with 4-6 pyrenoids in a single row; reproduction 

usually by aplanospores, very rarely by zygospores; conjugation scalariform; 

zygospores quadrangular, 15-18/i x 15-23^, corners somewhat 

rounded; aplanospores ellipsoid, 12-15/1 x 23-25 /i, projecting slightly 

on the convex side of the slightly curved sporangia; spore wall yellow 

to brown, punctate. (PI. XVIII, Figs. 23-25.) 

United States: Illinois, Charleston; Oklahoma (Taft Coll.). 

British Isles. 

Very abundant for several years in a lily pond on the campus of the 

Eastern Illinois State Teachers College at Charleston, Illinois; fruited there 

both in the spring and autumn months. Among the hundreds of aplanospores 

examined perhaps a total of 25-30 zygospores was found. The Oklahoma 

specimens had spores darker than the Illinois specimens. 

76. MouGEOTiA GRACiLLiMA (Hassall) Wittrock 1872. Bih. Kgl. 

Svensk, Vetensk,. A\ad. Handl. 1, p. 40. 

Vegetative cells 5-7 /t x 55-140/1; conjugation scalariform; sporan- 

gia dividing both gametangia; zygospores quadrate, with deeply con- 

cave sides, 20-25/1 X 20-28/1, angles refuse; spore wall minutely ver- 

rucose; aplanospores spindle-shaped. (PI. XIX, Figs. 1-2,) 

chusetts. 

United States: Texas; Michigan; Illinois to New York and Massa- 

Europe, generally distributed throughout.

MOUGEOTIA 109 

77. MouGEOTiA viRiDis (Kutzing) Wittrock 1872. Bih. Kgl. Svens\ 

Vetensk^. Akjid. Handl. 1, p. 39. 

Vegetative cells 6-

no ZYGNEMATACEAE 

Differs from A/, punctata in having zygosporangia with convex lateral 

walls and smaller dimensions. 

8i. MoucEOTiA AUSTRiACA Czurda 1932. Siisstvasserflora Mittel- 

europa. 9, p. 90, Fig. 82. 

Vegetative cells 7-9 /^ x 50-140 jt^; chromatophores with 2 pyrenoids; 

conjugation scalariform ; zygospores quadrangular, with concave sides 

and rounded corners bulging into the gametangia, 20-25^ x 27-30/i; 

spore wall golden-brown, thick, scrobiculate; pits about 1/^ in diam- 

eter. (PI. XIX, Figs. 11-12.) 

United States: Texas (Taft Coll.). 

Austria, Wiener-Neustadt. 

82. MouGEOTiA viRESCENs (Hassall) Borge 19 13. Siisswasserfiora 

Deutschland. 9, p. 43. 

Vegetative cells 8-9^^1 x 50-220/'.; conjugation scalariform; sporan- 

gia dividing both gametangia; zygospores quadrangular, with concave 

sides, ju, 29-35 X 29-35 ,a; ^^^^ colorless, smooth, with rounded corners. 

(PI. XIX, Fig. 16.) 


Canada, Maritime Provinces (Hughes Coll.); England; Germany; 

France to Yugoslavia; China, Yunnan (Li Coll.), and Szechwan (JaoColl.). 

83. MouGEOTiA ROTUNDANGULATA Jao 1935. Sittcnsia. 6, p. 579, 

PI. 2, Figs. 45-46. 

Vegetative cells 8-10 /a x i 60-420 m; chromatophores with 8-14 

pyrenoids in a single row; conjugation scalariform; sporangia dividing 

both gametangia; zygospores quadrangular, somewhat tumid, 32-35 m x 

/J., 32-35 with rounded angles; wall scrobiculate with scattered pits, 

1-2/X in diameter, colorless at maturity. (PI. XIX, Figs. 13-14.) 


84. MouGEOTiA PUNCTATA Wittfock 1 867. Algologiska Sttidier. I. 

Uppsala. 

Vegetative cells 8-10 /a x 50-120^1; chromatophores with 4 pyrenoids 

in a row; conjugation scalariform; sporangia dividing both gam- 

etangia; zygospores quadrangular with concave sides and obtuse or 

retuse angles, 30-38 /x x 30-3S/M, 18-20 /a thick; outer wall finely scrobic- 

ulate, inner nearly smooth. (PI. XIX, Fig. 15.) 

United States: Wisconsin (Prescott Coll.); Florida (Tiffany Coll.). 

Sweden, Upland; Brazil (Drouet Coll.). 

Jao has recently described (Bot. Bull. Acad. Sinica. I, p. loi, 1947) a 

new species, M. subpunctata, that closely resembles this species, but the cell 

diameters are 5-6.5/1 and the spores are 20-25 /xx 18-25/1.

MOUGEOTIA III 

85. MouGEOTiA QUADRANGULATA Hassall 1843. Ann. and Mag. 

Nat. Hist. 11, p. 434. 

Vegetative cells 8-13 a^ x 50-140/^; chromatophore with 8-16 pyre- 

noids in a single row; conjugating cells geniculate; conjugation scalar- 

iform; sporangia dividing both gametangia; zygospores quadrangular 

with straight sides and truncate corners or rarely with angles retuse, 

28-40 A^ X 28-40 /a; spore wall colorless, punctate; aplanospores obliquely 

ovoid, 20-21^1 X 36-44 /u. (PI. XIX, Figs. 19-20.) 

United States: Illinois to Louisiana eastward to Newfoundland; Massa- 

chusetts; Florida. 

Generally distributed from England to Russia and China; south to 

North Africa and Madagascar; South America, Chile. 

86. MouGEOTiA PALUDosA G. S. Wcst 1899. ]our. Bot. 37, p. 108, 

PI- 395. Figs. 4-6- 

Vegetative cells 11.5-13.5 /x x 70-1 /x; 85 chromatophores short, occupying 

about one-third the length of the cell, with 4-6 pyrenoids in a 

single row; fertile cells recurved; conjugation scalariform; sporangia 

dividing both gametangia; zygospores ovoid to quadrangular-ovoid, 

angles undulate truncate, 32-28 /x x 44-49 /a; outer wall of zygospores 

thick, smooth; inner wall smooth, thin. (PI. XIX, Figs. 17-18.) 

England. 

87. MouGEOTiA ASPERA WoronicHin 1923. Notulae Syst. Inst. 

Crypt. Hort. Bot. Petrop. 2, p. 192. 

Vegetative cells 1 3-1 6.5 /x x 78-112^1; conjugation scalariform; sporangia 

dividing both gametangia; zygospores globose, 36-46/* in diam- 

eter, rarely ovoid, 46/x x 66/j.; spore wall pale brown, punctate. 

Asia Minor, Tiflis; Finland. 

88. MouGEOTiA FRAGiLis (ZcUcr) dc Toni 1889. Sylloge Algarum. 

I (2), p. 721. 

Vegetative cells 17-22/1 x 85-200 /a; conjugation scalariform; zygo- 

spores quadrangular, 22-28/1 x 22-28/1; spore wall smooth. 

Burma, Pegu. 

89. MouGEOTiA TENERRiMA G. S. Wcst 1914. Metti. Soc. Ncucha- 

teloise Sci. Nat. 5, p. 1028. 

Vegetative cells 4-5/1 x 11 0-135 /a; chromatophores with 6 pyrenoids 

in a single row; zygospores unknown; aplanospores oblique- 

ellipsoid, 12-13 /I X 24-25/1., ends slightly mammillate, wall smooth. (PI. 

XIX, Figs. 30-31.) 

South America, Colombia.


90. MoucEOTiA TROPICA (W. & G. S. Wcst) Transcau 1926. Ohio 

Jour. Sci. 26, p. 325, PL 7, Fig. 112. 

Vegetative cells 6-7/1 x 36-56/1; chromatophore with 2 pyrenoids; 

zygospores unknown; aplanospores obliquely globose with projecting 

mammillate solid processes, wall yellow-brown, scrobiculate, 27-28/1 x 

27-29/1, with the processes 42-46/1 in length. (PI. XIX, Fig. 21.) 


91. MouGEOTiA MiAMiANA Transcau 1934. Trans. Amer. Micros. 

Soc. 53, p. 222, PL 19, Figs. 41-42. 

Vegetative cells 6-^.1 ti x 60-130/1; chromatophores with 2-6 pyre- 

noids; zygospores unknown; aplanospores formed in the middle of 

straight or slightly angled cells; outer sporangium wall covered at all 

stages by a pectic layer; aplanospores globose to ovoid to ellipsoid with 

projections at either end; globose spores 18-20/t in diameter, ellipsoid 

spores 16-18/1 x 25-32/1; spore wall yellow, punctate. (PI. XIX, Figs. 

22-23.) 

United States: Oklahoma, Miami, August 14, 1932 (Taft Coll.). 

92. MouGEOTiA VENTRicosA (Wittrock) CoUins 1912. Tufts Col- 

lege Studies. 3, p. 76. 

Vegetative cells 6-9/1 x 100-140 /i; chromatophores with about 4 

pyrenoids in a single row; zygospores unknown; aplanospores obliquely 

ellipsoid to subglobose, 12-24/1 x 16-29/1; spore wall smooth, yellowbrown. 

(PI. XIX, Fig. 24.) 

United States: Reported from California, Michigan, and Pennsylvania. 

Have seen no specimens. 

Sweden; Latvia. 

93. MouGEOTiA PRONA Transcau 1926. Ohio Jour. Set. 26, p. 326, 

PL 7, Figs. 109-11. . 

Vegetative cells 8-12/1 x 60-1 40 (-280) /i; chromatophores 2 with 

the nucleus between, pyrenoids 4-6 in each; zygospores unknown; 

aplanospores obliquely ellipsoid with ends produced and truncate, 

20-24/1 X 5o-52(-6o) /i; spore wall faintly yellow, punctate, with 

rounded or retuse ends. (PI. XIX, Figs. 26-28.) 

United States: New York, High Hill, Long Island, growing in a road- 

side spring. 

During the formation of an aplanospore an enlargement of the middle 

portion of the cell develops. Simultaneously the protoplast begins to con- 

tract and the 2 chromatophores move into the enlargement, i on each side 

of the nucleus. The contracted protoplast is cut off from the 2 narrow parts 

of the sporogenous cell by cross walls. A little later the spore wall develops. 

Similar stages have been seen in other species of Mougcotia.

MOUGEOTIA 113 

94. MouGEOTiA MAYORi (G. S. West) Transcau 1926. Ohio four. 

Sci. 26, p. 327. G. S. West. Mem. Soc. Neuchateloise Sci. 

Nat. 5, p. 1027. 

Vegetative cells 13-15^^ x 235-315 jm; chromatophore with 11-14 

pyrenoids in an irregular row; zygospores unknown; aplanospores 

obliquely ellipsoid with truncate ends, 24-26 /a x 34-38 /a; spore wall 

yellow, punctate. (PI. XIX, Fig. 29.) 

South America, Colombia. 

95. MouGEOTiA RAVA Transcau 1944. Ohio Jour. Sci. 44, p. 244. 

Vegetative cells 8-12 /a x 32-120 a^; chromatophore with 4-8 pyre- 

noids in a row; reproducing by aplanospores which are formed mostly 

outside the recurved sporiferous cells; aplanospores globose, 16-20 /a in 

diameter; wall gray-brown and smooth. (PI. XIX, Fig, 25.) 

United States: Mississippi, Starkville; Louisiana, Alexandria (Hicks 

Coll.); Texas, Austin (Taft Coll.). 

The species resembles certain aplanosporic filaments of M. calcarea. 

The metallic gray-brown color of the spores is distinctive, also the absence of 

conjugation. 

SPECIES NOT IN PROPER SEQUENCE 

96. MouGEOTiA suBPALUDosA Ley 1944. Sinensia. 15, p. 97. 

Vegetative cells 9-1 ia'- x 30-1 52 /a; pyrenoids 2; conjugation scalar- 

iform; sporangia dividing both gametangia; zygospores quadrangular- 

ovoid, sometimes much rounded, 25-29 /a x 2 1-29 /a, 20-27 /a thick; spore 

wall very thick, smooth, deep yellow at maturity. (PI. XIX, Fig. 32.) 

China, Woo-Yang-She, northern Kwangtung, February 21, 1942. 

Resembles Number 86, Mougeotia paludosa West, but differs in smaller 

dimensions throughout. 

97. Mougeotia chlamydata Prescott 1947. Ohio four. Sci. 47, 

p. 130. 

Vegetative cells 12-16/A x 200-240 /a; chromatophores with 4-6 pyre- 

noids in a row; conjugation scalariform; zygospores compressed-globose, 

26-28 /A X (30-) 32-38 /a; sporangium wall bluish (by refraction), spore 

wall thick, metallic green, and smooth. The sporangium wall is quite 

unique in that after conjugation it has an inner and outer layer of cel- 

lulose separated by a thick pectic layer. The outer layer disintegrates 

equatorially as the spore reaches maturity and the pectic layer dissolves 

leaving a collar around the base of each half of the conjugating tube. 

(PI. XIII, Fig. 19.) 

Ecuador, volcano Cotopaxi, hanging bog at 14,000 feet. 

Should be near M. cyanea, Number 55. The spore is compressed at 

right angles to the conjugating tube.

114 

ZYGNEMATACEAE 

98. MouGEOTiA coTOPAxiENSis Prcscott 1947. Ohio Jour. Set. 47, 

p. 132. 

Vegetative cells 10-16 /li- x 80-250 /a; chromatophores with 2-4 pyrc- 

noids in a row; conjugation scalariform; zygospores globose or com- 

pressed at right angles to the short conjugating tubes, 30-32 /^ in diam- 

eter; spore wall steel-blue, scrobiculate with pits about i /x in diameter, 

4-5 jn apart; sporangium wall thin, smooth. (PI. XIII, Fig. 20.) 


Should be near M. cyanca, Number 55. 

99. MouGEOTiA KWANGSiENSis Jao 1947. Bot. Btill. Acad. Sinica. 

1, p. 100. 

Vegetative cells 12-13^ x 115-313/x; chromatophores with 4 to 6 

pyrenoids in a single row; gametangia geniculate; zygosporangia divid- 

ing both gametangia, compressed-globose; zygospores, 35-42 ju, x 33-35^; 

outer spore wall thick, lamellose, and hyaline; spore wall yellow, either 

smooth, or with thin reticulate wrinkles. It is possible that the wrinkles 

are due to contraction and are not morphological structures. 

smaller. 

China, Suijen, common in rice fields. 

Should be placed near M. cherolêana (No. 64), which is similar but 

List of the Species of MOUGEOTIA with Number 

acadiana Transeau 1934 47 

adnata Iyengar 1932 

9 

africana (G. S. West) Transeau 1944 

17 

americana Transeau 1918 65 

angolensis W. & G. S. West 1897 45 

angusta (Hassall) Kirchner 1878 i 

areolata Transeau 1934 

aspera Woronichin 1923 

atubulosa Krieger 1941 

austriaca Czurda 1932 

boodlei (W. & G. S. West) Collins 1912 75 

caelestis Transeau 1934 

caimani Transeau 1938 

calcarca (Cleve) Wittrock 1872 5 

capucina (Bory) Agardh 1824 72 

cherokeana Taft 1934 64 

chlamydata Prescott 1947 97 

corniculata Hansgirg 1886 

cotopaxiensis Prescott 1947 

crassa (Wolle) de Toni 1889 23 

3° 

87 

5^ 

81 

24 

63 

^ 

9^

MOUGEOTIA 115 

craterophora Bohlin 1901 69 

cyanea Transeau 1926 55 

daytonae Transeau 1934 

delicata Beck 1926 73 

depressa (Hassall) Wittrock 1880 49 

disjuncta Transeau 1934 53 

drouetii Transeau 1938 

10 

elegantula Wittrock 1872 74 

ellipsoidea (W. & G. S. West) Czurda 1932 6 

floridana Transeau 1934 

fragilis (Zeller) de Toni 1889 88 

gelatinosa Wittrock 1889 $1 

genufiexa (Dillwyn) C. A. Agardh 1824 

20 

globulispora Jao 1935 

36 

gotlandica (Cleve) Wittrock 1872 33 

gracillima (Hassall) Wittrock 1872 7^ 

granulosa Transeau 1938 7^ 

handelii Skuja 1937 

hirnii Transeau 1934 

irregularis W. & G. S. West 1897 

jogensis Iyengar 1932 

\erguelensis Krieger 1941 

J{wangsiensis Jao 1947 

laetevirens (Braun) Wittrock 1877 

laevis (Kiitzing) Archer 1866 38 

lamellosa Jao 1935 

34 

macrospora (WoUe) de Toni 1889 

21 

maltae Skuja 1926 

12 

mayori (G. S. West) Transeau 1926 94 

megaspora Wittrock 1872 27 

miamiana Transeau 1934 

9^ 

micropora Taft 1934 29 

microverrucosa Krieger 1941 35 

nummuloides (Hassall) de Toni 1889 25 

oblongata Transeau 1934 43 

oedogonioides Czurda 1931 54 

opelousensis Taft 1944 

4^ 

operculata Transeau 1934 57 

ornata Jao 1935 28 

ovalis (Hassall) Nordstedt 1886 50 

ovalispora Krieger 1941 

4° 

61 

4^ 

19 

70 

16 

u 

99 

46 

18

ii6 ZYGNEMATACEAE 

pahidosa G. S. West 1899 

parvttla Hassall 1843 3 

pawhusl{ae Taft 1934 58 

pectosa Transeau 1934 51 

poinciana Transeau 19^4 62 

proditcta G. S. West 1907 78 

prona Transeau 1926 93 

pulchella Wittrock 1871 37 

punctata Wittrock 1867 84 

quadran gidata Hassall 1843 85 

rava Transeau 1944 95 

recurva (Hassall) de Toni 1889 8 

regellii Skuja 1937 79 

reinschii Transeau 1934 13 

robusta (de Bary) Wittrock 1885 39 

rotundangulata Jao 1935 83 

sanjordiana Tiffany 1934 

scalaris Hassall 1842 15 

seminoleana Tiffany 1934 59 

sinensis Li 1933 

26 

sphaerocarpa Wolle 1887 14 

subcrassa G. S. West 1909 22 

subpaludosa Ley 1944 96 

sumatrana Schmidle 1895 31 

talyschensis (Woronichin) Czurda 1932 32 

tenerriina G. S. West 1914 89 

tenuissima (de Bary) Czurda 1932 

thylespora Skuja 1929 67 

transeaui Collins 1912 60 

tropica (W. & G. S. West) Transeau 1926 90 

tubifera Tiffany 1934 

tumidula Transeau 1914 

uberosperma W. & G. S. West 1897 

varians (Wittrock) Czurda 1932 44 

ventricosa (Wittrock) Collins 1912 92 

victoriensis G. S. West 1909 7 

vircscens (Hassall) Borge 191 3 

82 

viridis (Kiitzing) Wittrock 1872 77 

86 

42 

2 

4 

80 

68

CHAPTER TEN 

THE GENUS TEMNOGAMETUM W. & G. S. WEST 1897 

The vegetative cells and filaments of the species resemble those 

of Mougeotia. The cells are cylindric, five to twenty-five diameters 

long, each with a single axile platelike chromatophore. The 

pyrenoids are arranged either several in a single row, or are 

numerous and scattered. The cell sap in 2 of the species is purple. 

The behavior during reproduction is very different from that 

of the species of Mougeotia. The gametangia are short specialized 

cells formed at the ends of scattered vegetative cells. They are 

one to two diameters long and are gorged with starch and other 

food substances. In scalariform conjugation the adherent sides of 

two gametangia become distended and a hole develops within 

the ring of contact. These connecting walls widen and become 

the lateral walls of the quadrangular sporangium. Note that dis- 

tinct conjugating tubes are not formed as in Mougeotia. In lateral 

conjugation, two adjoining gametangia of the same filament 

enlarge most at the separation wall, and the wall gradually dis- 

appears. The gametes unite and the zygospore is obliquely 

spindle-shaped. Aplanospores and parthenospores may be formed 

from the reproductive cells. Only 4 species have been found—all 

within the tropics. 

Key to the Species of TEMNOGAMETUM 

I. Chromatophores with pyrenoids in a row 2 

I, Chromatophores with scattered pyre- 

noids 4. T. thaxteri 

2. Cell diameter io-12/x, zygospores 

(lateral conjugation) 20-40 ju, x 40- 

60 ju. I . T. tileanum 

2. Cell diameter 14-17/A, zygospores 

(lateral conjugation) 20-26 /a x 61- 

67^0, 2, T. heterosporum 

2. Cell diameter 14-20 /a, zygospores 

(lateral conjugation) 35-42 /a x 80- 

100 ju, 3. T. transeaui 

117

ii8 ZYGNEMATACEAE 

Descriptions ok Species 

1. Temnogametum uleanum (Mobius) Wille 1909. Pflanzen- 

familien, 'Nachtrage zum 1 Teil, 2 abt., p. 13, Fig. 3. 

Mobius. Hedwigia. 34, p. 175, PI. 2, Figs. i-io. 1895. 

Vegetative cells io-12/x x 60-120/x, with an axile chromatophore 

with about 4 pyrenoids, cell sap purple; cells elongating to 20-25 diameters 

at time of conjugation; conjugation usually lateral, sometimes 

scalariform; gametangia 20-30 /a long; zygospores by lateral conjuga- 

tion obliquely ovoid, 20-40^1 x 40-60 /x; zygospores by scalariform con- 

jugation quadrangular with truncate angles, 25-40 ju. x 30-50 m; spore 

walls transparent and smooth. Aplanospores rare but present. (PI. XX, 

Figs. 1-4.) 

Brazil, near Itajahi, March, 1894 (E. Ule Coll.). 

2. Temnogametum heterosporum W. & G. S. West 1897. ]our. 

Bot. 35, p. 37, PL 370, Figs. 5-9. 

Vegetative cells i^-iyiJ- x 90-200^1; chromatophores with 2-6 pyre- 

noids, color of cell sap unknown; conjugation scalariform and lateral; 

gametangia 22-40 jw in length; zygospores by scalariform conjugation 

quadrangular with concave sides, 39-50 /a x 48-59 m; zygospores by lat- 

eral conjugation obliquely ovoid, 20-26 ^ x 61-67 ju spore wall smooth, 

transparent. (PI. XX, Fig. 10.) 

Africa, Angola, Morro de Lopollo, February, i860 (Welwitsch Coll.). 

3. Temnogametum transeaui Prescott 1947. Ohio Jour. Sci. 47, 

p. 132. 

Vegetative cells 14-20^ x 100-400^, with a narrow, axial chroma- 

tophore with 2-4 pyrenoids in a row; conjugation lateral and scalar- 

iform; gametangia, 20-22 m x 20-30;", at the ends of vegetative cells; 

zygospores by lateral conjugation obliquely ovoid, yu. 35-42 x 80-100 /x; 

zygospores by scalariform conjugation, iu, 40-50 x 45-60 /x; median wall 

smooth, orange-brown at maturity. (PI. XX, Figs. 5-6.) 


4. Temnogametum thaxteri Transeau 1932. Ohio Jour. Sci. 32, 

p. 489, PI. I, Figs. 14-20. 

Vegetative cells 39-45 /^ x 220-360 m; chromatophore broad with 

30-120 pyrenoids scattered throughout; conjugation scalariform; gam- 

etangia 36-90 /x long; zygospores c|uadrangular-ovoid, 60-75;^ x 90-120 /u, 

occasionally in pairs which are somewhat longer and narrower; lateral 

walls concave; aplanospores tumid, about 60 m x 75 m- (PI- XX, Figs. 

7-9-) 

Trinidad, Cumuto Station, April 10, 1913 (Thaxter Coll.). 

The cell sap in this species is purple.

CHAPTER ELEVEN 

THE GENUS SIROCLADIUM RANDHAWA 1941 

This tentative genus is established on the basis of chromato- 

phores which resemble those of Mougeotia, and reproductive 

structures quite similar to those of Sirogonium. The vegetative 

cells are cylindric but variously curved, v^îth plane end walls. 

The chromatophores are two broad parietal plates, each with 

several pyrenoids in a row, and the nucleus is supported by a 

cytoplasmic pillar between the flat sides of the chromatophores. 

The gametangia may become organized after an unequal division 

of a vegetative cell, or from a short undivided vegetative cell. 

Conjugation occurs between reflexed gametangia in adjacent fila- 

ments. Adhesion is followed by the growth of a pectic ring about 

the area of contact, but without the formation of tubes. The one 

known species is terrestrial and has rhizoids extending into the 

soil both as elongated basal cells and as outgrowths from other 

cells of a filament. 


SiRocLADiuM KUMAOENSE Raudhawa 1941. Bot. Gaz. 103, p. 196. 

Vegetative cells cylindric, more or less irregularly bent, with plane 

end walls, 45-64 m x 120-210 /x; chromatophores 2; parietal plates 15-20 /x 

broad, each with 4 to 12 large pyrenoids arranged in a row. The nucleus 

is centrally supported by a cytoplasmic pillar between the 2 chromatophores. 

Conjugadon occurs between 2 geniculate gametangia without 

the formation of tubes. Receptive gametangia become inflated, zygo- 

spores are broadly ellipsoid, 42-70 /x x qo-io8/x; median spore wall yellow-brown 

and smooth. Parthenospores and aplanospores smaller and 

rounded, otherwise similar. (PI. XX, Figs. 11-14.) 

India, Upper Punjab, Almora, September and October, 1939. Found 

growing on moist clay on a ledge near a waterfall in the Kumaon Hills. 

Specimens of this remarkable plant have been examined by the author. 

The width of the chromatophores and the size of the pyrenoids are quite 

unlike any specimens of Sirogonium that I have seen. That it has certain 

features in common with this latter genus is unquestionable. In the specimens 

seen there was no evidence of spiral twisting of the chromatophores. 

It is possible that in the living material the chromatophores were even wider 

than the dimensions given above. 

119

CHAPTER TWELVE 

THE GENUS ENTRANSIA ELWYN HUGHES 1943 

The genus Entransia was established to classify an alga having 

simple filaments with cylindrical cells and one or two laminate 

parietal chromatophores extending lengthwise of the cell, with 

several irregular fingerlike processes extending outward and part 

way around the cell. Each chromatophore has several scattered 

pyrenoids. In young cells with a single chromatophore the nucleus 

is laterally placed near the center of the chromatophore. In mature 

cells the nucleus is in the bridge between the two chromatophores. 

The orientation of the two chromatophores with the nucleus between, 

the scattered pyrenoids, and the fingerlike processes extend- 

ing outward and more or less enclosing the cell contents suggest 

that the plant may belong to the Zygnemataceae. On the other 

hand it may belong to the Ulotrichaceae near the genus Ulothrix. 

Until the reproductive structures are found no definite disposition 

of the genus can be made. Named for E. N. Transeau. 


Entransia fimbriata Hughes 1943. Abstracts of Doctoral Disser- 

tations, The Ohio State University, 40, pp. 153-59; also in 

Amer. Jour. Bot., 35 (1948), p. 487. 

Filaments with cylindrical vegetative cells 19-22.4 ft x 16-64 /a; i or 

2 parietal chromatophores extending lengthwise of the cell, each with 

several lateral processes partly embracing the cell contents. There is a 

nucleus, in young cells located laterally and near the center of the 

chromatophore; in mature cells with 2 chromatophores the nucleus is 

in the bridge between them. (PL XX, Fig. 15.) 

Canada, Nova Scotia, Queens County, Charleston, July, 1941. Collected 

in a small artificial lake in the Port Medway River valley. 

Here is an interesting note. In this same lake Hughes collected 3 new 

species of Bulbochaete, i new Oedogonium, and a new Spirogyra. These 

were the only new species of filamentous algae found on the peninsula 

during two summer collecting trips, and in the examination of numerous 

collections made by other residents of Nova Scotia. Many other collectors 

have had similar experiences of finding one station that contained several 

new or rare species not met with elsewhere in the same region during a 

collecting period of several years.

CHAPTER THIRTEEN 

THE GENUS SPIROGYRA LINK 1820 

The species of Spirogyra are known to more people than those 

of any other genus of the filamentous green algae. For many 

years they have been seen and named in biology classes in secondary 

schools and colleges. They occur on all the continents and 

larger islands in fresh-water ponds, streams, and lakes. Among 

the filamentous green algae the genus Spirogyra ranks next to 

Oedogonium in the number of described species. 

In the following pages, 275 species are described, and it is 

highly probable that this number will be greatly increased as soon 

as habitats are visited repeatedly and collections are made by 

trained personnel. Most of our present knowledge is based on 

chance collections. Since we know that the fruiting period of 

many species is less than a fortnight, only repeated visits to the 

same station possibly can secure identifiable specimens of all the 

species present. 

Professor Jean Massart once remarked, "Why waste your time 

on Spirogyras—there are no species in that genus." It is true that 

there are some highly variable species among them, but I suspect 

that most of the species will be found to be remarkably uniform 

when once they have been described adequately. The older de- 

scriptions were quite incomplete and gave few details concerning 

spore walls, conjugating tubes, and even spore forms. Conse- 

quently, many diverse specimens were classified as belonging to 

the same species. 

The filaments of the Spirogyras are composed of cylindric cells, 

all very much alike except the first or basal cell which may 

develop as a rhizoid and anchor the filament at least during its 

early development. The vegetative cells of larger species often 

appear barrel-shaped under the microscope, and have been thus 

described and figured. This appearance usually is due to the 

pressure of the cover glass. Measurements of the diameters of 

vegetative cells should be made at the partition walls. Czurda 

123

124 

ZYGNEMATACEAE 

insists that cell lengths are of no taxonomic importance since 

they may be mocJiiied in some species by environmental condi- 

tions. Nevertheless there are some species in which the cells are 

relatively short (one-half to two diameters), and others in which 

they are relatively long (eight to twenty-five diameters). In these 

species at least, the cell lengths may be contributory evidence to 

their identification. Cells 6oom long have been seen in at least 

5 species, the diameters of which are between 201^ and 45/^ 

The chromatophores are ribbonlike or troughlike, with or 

without a median ridge, arranged in a left-handed, or counter- 

clockwise spiral in the parietal cytoplasm. The number of spirals 

in a cell may vary from one to sixteen. In some species the number 

of chromatophores is uniform. In others there are occasional cells 

in filaments with one more than the usual number— particularly 

in the one-spiraled species. How these arise is not known. In 

still other species the number regularly varies within certain limits. 

In determining the number of chromatophores in a given 

specimen, counts should be made only in filaments attached to 

the sporangia or gametangia being studied, as there may be vege- 

tative filaments of nearly the same dimensions but of another 

species present in any collection. In most species the number of 

spirals is readily determined by focusing just below an upper-half 

turn of the spiral, counting this turn as one and adding to it the 

number of optical intersections made by the spirals on the oppo- 

site side of the cell. In very large species and in those with tightly 

coiled chromatophores this may be impossible. In such species 

and in those with nearly straight chromatophores, the numbers 

are best determined by counting the ends of the spirals near the 

cross walls. 

Each chromatophore has from several to many disc-shaped 

pyrenoids spaced at regular intervals, and in certain species interrupting 

the median ridge. The margins of the chromatophores 

may be nearly smooth, or variously crenulate. Just after cell 

division the spiral pattern is continuous from one cell to the next, 

interrupted only by the thin partition wall. Chromatophores are 

examples of direct cytoplasmic inheritance. Through aplanospores 

they are derived directly from the chromatophores of the sporog- 

enous cells. Through zygospores they are derived from the chromatophores 

of the receptiue gametangia. 

The cells of a filament are enclosed in a pcctic sheath im to 17M

SPIROGYRA 125 

in thickness, and each cell may have an additional thin pectose 

wall and an inner cellulose wall next the protoplast. The trans- 

verse or end walls of the cells at maturity are of 4 types: plane, 

replicate, semireplicate, and colligate. These are probably funda- 

mental cell differences. The first three types have long been used 

to separate three primary groups within the genus. 

Following cell division the primary wall, or middle lamella of 

the partition wall, is composed of a pectic compound and has a 

plane surface. The secondary wall of cellulose also is plane in 

208 species. In 65 species the cellulose layer develops a circular 

cuplike infold. (PI. XXXV, Figs. 5-20.) Two other species have 

only a semicircular infold. (PI. XXXV, Figs. 1-4.) In the adja- 

cent cell the infold is opposite the plane half so that when these 

partition walls are seen from the side, the two folds resemble a 

partly open transom. 

Not infrequently, in the division just preceding the formation 

of gametangia, the walls are plane even in the replicate species. 

There is i species (S. colligata) in which the middle lamella con- 

tinues to grow in thickness and spread out over the ends of the 

cylindric wall. This process results in a collared diaphragm between 

successive cells. (PI. XXXI, Figs. 11-13.) Isolated exam- 

ples of collared diaphragms may be found in other species. 

When cells with plane walls separate, the free ends become 

rounded. Free end walls of replicate species have a narrow central 

bulge with a distinct shoulder. The free ends of semireplicate 

cells have an asymmetric pointed bulge on the half where the 

infold occurred. As cells age, the transverse walls may become 

thickened and distorted through pectinization. 

The replicate walls are curious structures. Since they first were 

seen, botanists have exercised their ingenuity to devise some important 

use or advantage for them. Frequently they have been 

held up as special adaptations for fragmentation. Yet all these 

botanists know that plane-walled filaments fragment without dif- 

ficulty. When fragmentation occurs throughout a filament, the 

protoplasts are on their way to disintegration, not to multiplication. 

The nucleus of a vegetative cell is located near its center, 

enclosed in cytoplasm supported by cytoplasmic strands, the outer 

ends of which usually adjoin a pyrenoid. 

The simplest method of propagation and survival over a dormant 

period is by akinetes. These may be cylindric thick-walled


cells, or the thickening may be unequally distributed and modify 

the usual cell form. (PI. I, Fig. i.) Aplanospores are formed by 

the contraction of the contents of vegetative cells and the growth 

of a new and distinctive spore wall. 

The "spore wall" is really a complex of three to five walls, one 

or more of which may be variously sculptured or ornamented. 

The outer wall is of cellulose and is usually colorless and trans- 

parent. Sometimes the outer wall is made up of two colorless 

layers, either of which may be thick and sculptured. The median 

spore wall at maturity is distinguished by its yellow to chestnut 

brown color resulting from chitinous deposits in or on the cellu- 

lose. This is the spore wall most frequently sculptured and ornamented. 

In some species the median wall also consists of two 

distinct chitinous layers. The inner spore wall is a thin cellulose 

layer lining the median wall and seldom seen, except when the 

spores are crushed. The median and the outer walls have a suture, 

more or less distinct, encircling the spore. At the time of germi- 

nation these walls split along this line, while the inner wall 

enlarges with the protoplast and becomes the wall of the one 

celled sporeling. The walls of zygospores are similar to those of 

aplanospores. 

The forms of Spirogyra spores are of three general types: 

ellipsoid (like an American football), ovoid (like a watermelon), 

and lenticular (a compressed spheroid). These forms may be 

slightly modified by elongation or compression but the curvatures 

of the polar ends remain the same. Usually there is no difficulty 

in recognizing the spore form of the 155 species with ellipsoid 

spores, and the 77 species with ovoid spores. There are 13 species, 

however, in which there is greater variation, and the form may 

be on either side of the border line between ovoid and ellipsoid. 

These are usually cared for in the keys by listing under both types. 

Compressed-ellipsoid, and compressed-ovoid spores are rare but 

do occur. The deviation of "lenticular" spores (30 species) from 

the form of a sphere may be as slight as an orange, or as great as 

a pocket watch. Obviously such spores are nearly circular in face 

view, and ovoid in side view. 

Conjugating tubes are usually formed by both gametangia 

(228 species) but in 31 species they are outgrowths of the male 

gametangia. In a few species in which the receptive gametangia 

become greatly distended the part of the tubes formed by them

SPIROGYRA 127 

may be widened and nearly disappear, leaving the tubes "appar- 

ently formed by the male gametangia." 

Another matter that must be determined early in the use of 

the key concerns the growth of the female, or receptive, gametangia 

during conjugation. Do they remain cylindric, or become 

slightly enlarged, or greatly distended or inflated ? The two latter 

conditions we judge by the enlargement relative to the thickness 

of the spore. If the spore just fits the distended part of the gametangium 

it is enlarged. If gametangial walls are much more 

distended than the diameter of the spore, the gametangium is 

inflated. The inflation may be only on the conjugating, or inner, 

side, or it may be only on the opposite, or outer, side. In many 

species the inflation is on both sides. 

The gametangial walls are not distended by the spore walls. 

Contrariwise the spore dimensions and forms are often limited by 

the gametangial walls. One can find many examples to prove this 

where spores formed in small gametangia are variously deformed 

by the rigidity of the gametangial wall. 

Another interesting fact is that there is no proportional relation 

between the combined volumes of the gametangia and the volumes 

of the spores in different species. Spore sizes in the same 

species, however, are usually larger or smaller depending upon 

whether the volumes of the gametangia are larger or smaller than 

the average. 

It is noteworthy that small spores in large gametangia are not 

free to move about as the cell is turned. The spores in all the 

Zygnemataceae are more or less fixed in position by an extremely 

dilute pectic gel that fills the entire cavity of the "empty" gam- 

etangia and sporangia. If these spaces were filled with water alone 

the position of the spores could be changed readily. 

The last essential feature of the description of a Spirogyra is 

the number of spore walls, the color, and surface markings of 

each. The kinds of ornamentation are best shown by illustrations. 

Not all drawings are equally satisfactory, but some of the most 

difficult have been sketched with remarkable accuracy. 

Spore wall features should be seen through an oil immersion 

lens, so that one can be sure to distinguish between the shadows 

of spore contents and actual wall structures. In drawing spores 

the contents should be omitted, since they are of no taxonomic 

value, while the wall characteristics have great importance.


Spore form, spore size, and wall ornamentation in hybrid 

zygospores are produced by the cytoplasm of the receptive gamete. 

For example, in collections containing filaments of two species 

interconjugating, the spore is always similar in form and approx- 

imate size to that of the specific filament in which the spore is 

formed. Hybridization between a species with plane-walled spores 

and a species with ornamented spore walls results in plane-walled 

or ornamented zygospores, depending upon the specific filament 

in which the receptive gamete is located. These facts fit in with 

observations on the movements of gametes during conjugation in 

which the male gamete moves into and through the cytoplasm of 

the female gamete and becomes enclosed by it. Thus the surface 

of the female gamete alone underlies the spore wall during its 

development. This is not interpreted as cytoplasmic inheritance. 

More probably the factors for these qualities of the cytoplasm are 

in the chromosomes. The cytoplasm is merely the mechanism by 

which spore wall forms, sizes, and patterns are formed. 

The processes of gamete organization, movement, and union 

usually occur during the night. To study the successive steps 

through the microscope one must avoid subjecting the cells to 

intense light and high temperatures during the observations. 

Under these conditions the motile gametes may stop moving and 

become lodged at the sides or ends of the receptive gametes. This 

abnormal condition may be seen in published photographs of the 

process. Observations are best made at short intervals by turning 

the light on and oflf or by tilting the mirror backward and forward. 

Analysis of Characteristics of the 275 Species 

OF Spirogyra Here Described 

Number of species with end walls plane is 208; semireplicate, 2; rep- 

licate, 65. 

Extreme diameters of vegetative cells with end walls plane are 10-200/1; 

semireplicate, 12-18/1; replicate, 8-61 /i. 

Number of chromatophores in species with end walls plane is i to 16; 

semireplicate, i ; replicate, i to 4. 

Number of species usually having i chromatophore is 129; approx- 

imately 2 to 5 chromatophores, 109; and 6 to 16 chromatophores, 37. 

Of the 208 species with plane end walls, the usual mode of conjugation 

is scalariform in 166, scalariform and lateral in 26, and lateral in 10. 

Conjugation is very rare or unknown in 6.

SPIROGYRA 129 

Of the 2 species with semireplicate end walls, conjugation is scalariform 

in I, and unknown in the other. 

Of the 65 species with repHcate end walls, the usual mode of conjuga- 

tion is scalariform in 33, scalariform and lateral in 25, and lateral 

in 6. Conjugation is unknown in i species. 

Reproduction by zygospores alone occurs in 242 species; by both aplan- 

ospores and zygospores in 25 species; and by aplanospores alone in 

8 species. 

Conjugating tubes are formed by both gametangia among plane-walled 

species in 182; among semireplicate species in i; and among rep- 

licate-walled species in 55. 

Conjugating tubes are formed by the male gametangia in 25 plane- 

walled species, and in 12 replicate species. In several other species 

with inflated receptive gametangia, they appear to be formed by the 

male gametangia when seen in mature condition only. 

A majority of the species with male conjugating tubes have short reproductive 

cells and longer vegetative cells alternating singly or in 

pairs in the filaments. The reproductive cells (pro-gametangia) 

can be distinguished readily before conjugation by their dark green 

color and dense cell contents. The vegetative cells have thin light 

green chromatophores and very transparent cytoplasm. Similar 

cell differences also characterize species of Temnogametum and 

Sirogonitim. In all these species there is an evident transfer of food 

substances from the vegetative to the reproductive cells, before the 

initiation of conjugation or spore formation. 

Spores are basically ellipsoid in 155 species; ovoid in 77; varying from 

ellipsoid to ovoid in 13; and more or less compressed-globose to 

lenticular in 30. 

Of the 25 species known to produce both zygospores and aplanospores, 

7 occur among the plane-walled species, and 18 among the replicate 

species. 

Key to the Species of SPIROGYRA 

I. Reproduction by zygospores 2 

I. Reproduction by aplanospores (zygospores unknown or rare) 183 

2. End walls of cells all plane 3 

2. End walls of cells distinctly and 

uniformly colligate i57- '5'. colligata 

2. End walls of cells semireplicate 132 

2. End walls of cells replicate (in fruiting filaments many 

plane) 134


END WALLS PLANE 

USUALLY ONE CHROMATOPHORE 

3. Tubes evidently formed by projections from both gam- 

etangia 4 

3. Tubes formed wholly, or almost wholly, by the male gam- 

etangia 117 

4. Vegetative cells with i chromatophore (rarely in some 

cells 2) 5 

4. Vegetative cells usually with more than i chromatophore 

(i-) 2-16 46 

5. Median spore wall smooth (outer walls scrobiculate in Nos. 

II, 40, and 41) 6 

5. Median spore wall punctate, scrobiculate, reticulate, or ver- 

rucose 

6. Spores rather uniform (in optical section may appear 

variable because seen at different angles in different 

cells) 7 

6. Spores distinctly polymorphic when seen from the same 

angle (ellipsoid, ovoid, globose, and irregular) 33 

7. Spores ellipsoid 9 

7. Spores ovoid to cylindric-ovoid 24 

7. Spores globose or compressed-globose 8 

8. Spores compressed-globose, diam- 

eter 55-65;^^ 152. S. discoidea 

8. Spores globose, or compressed- 

globose, diameter 85-95 /a i53- '^- sphaerospora 

ONE CHROMATOPHORE 

SPORES USUALLY ELLIPSOID, MEDIAN WALL SMOOTH 

9. Sporangia cylindric, or enlarged 10 

9. Sporangia inflated on both sides (larger than the spores) ... 19 

9. Sporangia inflated mostly or only, on the conjugative side. . 

35 

14 

9. Sporangia inflated mostly or only, on the outer side 23 

10. Diameter vegetative cells less than 40/14 11 

10. Diameter vegetative cells more 

than 40/4, spore diameter 34-38/u. 6. S.condensata 


than 40 /x, spore diameter ju. 42 or 

more 7. 5. varijormis 


than 60/1, spore diameter 60-66/1 33. S.gallica

SPIROGYRA 131 

II. Most of the spores less than 28 /a in thickness 12 

II. Most of the spores more than 28 ju, in thickness 13 

12. Diameter vegetative cells 11- 

14.5/1, sterile cells inflated or 

bullate 50. 5. porangabae 


sterile cells bullate 21. S. bullata 

12. Diameter vegetative cells 18-26 /i. i. S. communis 

12. Diameter vegetative cells 25-29 /a 2. S.intorta 

13. Diameter vegetative cells 24-30/1, diameter 

zygospores 28-3310. 3- ^^^ juergensii 

13. Diameter vegetative cells 29-39 /a, diameter 

zygospores 27-36/1 4. .S. singularis 

13. Diameter vegetative cells 32-40 /a, diameter 

zygospores 36-43 /a 5.5. silvicola 

14. Vegetative cells less than 30/1 in diameter 15 

14. Vegetative cells 30-40 /x in diameter 17 

14. Vegetative cells more than 40/1 in diameter 18 

15. Diameter vegetative cells 19-21 /a 18. S. gibberosa 

15. Diameter vegetative cells 16-24/1 8. 5. gracilis 

15. Diameter vegetative cells 23-30 /j. 16 

16. Fertile cells only slightly inflated 9. S. jragilis 

16. Fertile cells strongly inflated 10, S.teodoresci 

17. Median spore wall smooth, outer scro- 

biculate 11. S. pseudovarians 

17. Median spore wall smooth, outer 

smooth 12, S. varians 

17. Median spore wall smooth, with dark 

brown polar caps 13- '5'. bicalyptrata 


diameter spores 40-50 /t 14. 5. circumlineata 


diameter spores 35-40 /a 15, 5. supervarians 

19. Vegetative cells less than 24/1 in diameter 20 

19. Vegetative cells more than 24 /a in diameter 21 

20. Chromatophore i, diameter veg- 

etative cells 15-19/1, spore length 

/A 45-55 16. 5. fennica 

20, Chromatophore 1-2, diameter 

vegetative cells 17-20/1, sterile 

cells bullate 22. S. pratensis

132 

ZYGNEMATACEAE 


etative cells 20-24 M, spore length 

48-60 /A 17. 5. part' Ilia 


etative cells 20-25^1, spore length 

52-72^1 26S. 5. macrospora 

21. Fertile cells short, globose, spores 

28-33/x X 30-50/1 2:5. 5. affinis 

21. Fertile cells longer, fusiform-inflated 22 

22. Spore diameter 20-30 m, yellowbrown 

27. 5. subsalsa 

22. Spore diameter 22-29 /x, yellow. . 9. S.jragilis 

22. Spore diameter 27-33 ju, yellow.. 24. S.catetiaefonnis 

22. Spore diameter 28-38 jn, brown. . 25. S.subsalina 

23. Diameter vegetative cells 30-^5 /t 19. 5. borgeana 

23. Diameter vegetative cells 37-42 /a 20. 5. calcarea 

ONE CHROMATOPHORE 

SPORES USUALLY OVOID, MEDIAN WALL SMOOTH 

24. Vegetative cells usually less than /a 40 in diameter 25 

24. Vegetative cells usually more than 40/1 in diameter. ... 31 

25. Diameter vegetative cells less than 15 /a 26. S.fiavescens 


26. Spore diameter usually less than 30 /a 27 

26. Spore diameter usually more than 30/1 28 

27. Spores ovoid, diameter 18-20 /a 27. S. subsalsa 

27. Spores ovoid, diameter about 24/A. . 

27. Spores ovoid-ellipsoid, diameter 24- 

. . 28. S. paludosa 

29/A (usually aplanospores) 29. 5. mirabilis 

28. Fertile cells cylindric or enlarged 29 

28, Fertile cells inflated on one or on both sides 30 

29. Diameter zygospores 28-38 /a, yellow. 30. S.longata 

29. Diameter zygospores 33-38/1, brown. 269. S.indica 

29. Diameter zygospores 36-43/1, yellowbrown 

5. 5. silvicola 

29. Diameter zygospores 37-57 M, outer 

wall of 2 layers 40. 5. uelata 

30. Fertile cells inflated on both sides 32. S.siiecica 

30. Fertile cells slightly inflated, second 

outer wall scrobiculate 40. iS'. velata 

30. Fertile cells inflated on the inner 

side \2. S. vartans

31. Diameter vegetative cells more than 

SPIROGYRA 133 

60 /x 33- ^- g

134 

ZYGNEMATACEAE 

39. Diameter vegetative cells 25-33 ju, ^^^' 

tile and sterile cells cylindric 47- "^^ lugerheimii 

39. Diameter vegetative cells 18-25/j., ster- 

ile cells buUiform 4S. 5. tajtiana 

39. Diameter vegetative cells 14-18 /x, ster- 

ile cells not inflated 49. 5. perjorans 

39. Diameter vegetative cells 11-14^, ster- 

ile cells inflated or bulliform 50. .V. porangabae 

40. Diameter vegetative cells 11-14/A, 

fertile cells slightly inflated 50. 5. porangabae 

40. Diameter vegetative cells 16-19^1^, 

median spore wall grooved 51. 5. jyiituitijossa 


median spore wall reticulate.... 52. S.sl{ujae 

40. Diameter vegetative cells 18-25 /-a, 

median spore wall punctate 48. 5. tajtiana 


median spore wall punctate 53- '^^ hoehnei 

40. Diameter vegetative cells 29-35 )u., 

median spore wall coarsely punc- 

tate 54- '^^ robusta 

41. Diameter vegetative cells 12-16/x 179. S.taylorii 

41. Diameter vegetative cells 22-26 /a 55- '^- subpapulata 

41. Diameter vegetative cells 28-32)". 56. S.papulata 

41. Diameter vegetative cells 30-40 m 57- "^^ scrobiculata 

41. Diameter vegetative cells about 17/^.. 271. S.sibirica 

42. Fertile cells inflated mostly on the conjugative side 43 

42. Fertile cells enlarged or inflated on both sides 44 

43. Diameter vegetative cells 32-38 /j-, median 

spore wall punctate 58. 5, aphanoscidpta 

43. Diameter vegetative cells 30-40 a^, median 

spore wall coarsely scrobiculate. 57. S. scrobiculata 

43. Diameter vegetative cells 39-45 M 59- 

'^- kpffirita 

44. Median spore wall verrucose. ... 60. S.tuberculata 

44, Median spore wall irregularly 

corrugate 61 . 5. daedalea 

44. Median spore wall irregularly 

reticulate 62. 5. daedaleoides 

45. Spores with median wall finely verrucose 

^^- ^- australensis 

45. Spores with median wall reticulate.. 64. S.labyrinthica 

45. Spores with median wall finely gran- 

ulate 272. S. atasiana

SPIROGYRA 135 

END WALLS PLANE 

(one-) two to sixteen CHROMATOPHORES 

46. Spores globose, ovoid, or ellipsoid, not laterally com- 

pressed 47 

46. Spores globose, ovoid, or ellipsoid, laterally compressed 105 


47. Median spore wall not smooth 75 

SPORES NOT LATERALLY COMPRESSED 

MEDIAN WALL SMOOTH 

48. Vegetative cells with less than 9 chromatophores 49 

48. Vegetative cells with more than 9 chromatophores. ... 71 

49. Fertile cells cylindric, or enlarged 50 

49. Fertile cells inflated 72 

50. Spores ellipsoid or cylindric-ellipsoid 51 

50. Spores ovoid or cylindric-ovoid, rarely globose 62 

51. Vegetative cells usually less than 45 /a in diameter 52 

51. Vegetative cells usually 45-60 /a in diameter 54 

51. Vegetative cells more than 60 /la in diameter 56 

52. Chromatophores 2 to 3 in each cell 53 

52. Chromatophores 2 to 4, diam- 

eter vegetative cells ju- 32-37 66. S. irregularis 

52. Chromatophores 3 in each cell. . 67. S.juellebornei 

52, Chromatophores 2 in each cell, 

spores iJi 2^7,2 X 51-61 ju, 68. 5. microspora 

52. Chromatophores 2 in each cell, 

spores 38-42 /x X 60-78 /x 69. 5, hollandiae 

53. Diameter vegetative cells 21-32 û, 70. S.submarina 

53. Diameter vegetative cells 36-41 /a 71. 5. rivularis 

53. Diameter vegetative cells 38-48 fi 72. 5. biformis 

54. Chromatophores, 3, 1-3, or 2-3 55 

54. Chromatophores 2-4 li- 

^- hyalina 

55. Chromatophores 3, diameter vegeta- 

tive cells 55-60 )U, 74- 

55. Chromatophores (i-)3, diameter veg- 

etative cells 48-54 i". 

55. Chromatophores 2 to 3, diameter veg- 

IS- 

'^- pseudoneglecta 

^- Columbiana 

etative cells 49-62 M 76. 5. angolensis 

56. Diameter vegetative cells between 60 and 80 /a 

57 

56. Diameter vegetative cells between 80 and 120 ix 60 

56. Diameter vegetative cells more than i20ju. 61

136 

ZYGNEMATACEAE 

57. Spore diameters less than 60 /x 58 

57. Spore diameters greater than 60 /x 

58. Chromatophores 2 to 3, spores 

57-5S/X X 69-71 /M 

58. Chromatophores 4, spores about 

Tl- 

^- tvdwitschii 

50M X /i. 75-100 "]%. S. parvispora 

59. Chromatophores 3 to 4, spores 63-68 /^ 

X 120-140 /x 79- '^'- titrjosa 

59. Chromatophores (2-3)4, spores 57- 

68m X 100-21GJLC 98. 5. szechwanensis 

59. Chromatophores 3 to 5, spores 60-80 /x 

X 90-1 70 /x 80. 5. nitida 

60. Chromatophores (2-) 3 (-4), di- 

ameter vegetative cells 86-92^. . . 81, S. hymerae 

60. Chromatophores 4, diameter veg- 

etative cells 90-1 15 /x 82. 5. setiformis 

60. Chromatophores 4-6, diameter 

vegetative cells 1 15-128 /x 83. 5. elliptica 


vegetative cells 90-100 jtx 84. 5. wollnyi 


vegetative cells 98-1 10 ju 86. 5. yiinnanensis 


chromatophores 6-8 87. 5. hatillensis 


chromatophores 3 to 8 88. 5. ellipsospora 

61. Diameter vegetative cells i58-i66,u, 

chromatophores 5 to 6 89. vS. splendida 

62. Vegetative cells less than 60 /x in diameter 63 

62. Vegetative cells more than 60/^1 in diameter 68 

63. Chromatophores 3 or less in each cell 64 

63. Chromatophores 4 to 5, diameter veg- 

etative cells 50-60 /x 90. 5. emilianensis 

64. Vegetative cells with 2 chromatophores 65 

64. Vegetative cells with \ chromatophores 66 

64. Vegetative cells with 2 or ^ chromatophores (rarely i in 

No. 41 ) 67 


ile cells inflated to 50/x 91. 5. exilis 


ile cells inflated to 75/x 92. 5. distenta 

59

66. Spores 34-48 i". x 48-54^1 93- 

66. Spores 46-50^1 x 81-124 /a 94. 

66. Spores 54-64 /x x 75-100 ju. 95- 


SPIROGYRA 137 

'^' triplicata 

.S. siamensis 

'^- neglecta 

spores 31-40 /A (outer wall single) 96. 5. decimina 


spores 40-44 /i (outer wall single) 9']- ^- pi^na 

67. Diameter vegetative cells 40-50;". (second 

outer spore wall hyaline, scro- 

biculate) /\i. S. occidentalis 

68. Vegetative cells usually less than 75 m in diameter 69 

68. Vegetative cells usually more than 75 m in diameter 70 


tive cells 55-67 /A 95- '^- neglecta 

69. Chromatophores 3-4, diameter vege- 

tative cells 60-78 M (spore usually ellip- 

soid) 80. 5. nitida 

70. Diameter spores 57-68 /x, chromatophores 

4-(3-2) 98. 5. szechwanensis 

70. Diameter spores 87-108 a^, chromatophores 

3 to 4 99. 5. jugalis 

71. Vegetative cell diameter 100-120 /x, 

chromatophores 13-15 100. S. margaritata 

71. Vegetative cell diameter 1 50-1 89 /x, 

chromatophores 12-14 loi. 5. polytaeniata 

72. In each cell 2 chromatophores 73 

72. In each cell 2 or 3 chromatophores 74 

72. In each cell 4 to 6 chromatophores 102. S.jaoensis 

73. Zygospores ellipsoid, diameter vegeta- 

tive cells 20-24/". 103. S. baileyi 


tive cells 44-48)" 104. S. buchetii 


tive cells 60-75 /A ^°5- ^- bichromatophora 


chromatophores 2 to 3 106. S. rhizoides 

74. Diameter vegetative cells 40-50 a^, 

chromatophores 2 to 3 107. S. dubia 

74. Diameter vegetative cells 55-67 m, 

chromatophores 3 95- 

'^- neglecta


8i 

8i 

SPORES NOT LATERALLY COMPRESSED 

MEDIAN WALL NOT SMOOTH 

75. Diameter vegetative cells between 16 /x and 25 m 76 

75. Diameter vegetative cells mostly between 25^ and /u. 35 77 

75. Diameter vegetative cells between 35^1 and 60 i^ 84 

75. Diameter vegetative cells between 60 /x and 125 /li 96 

76. Spores ellipsoid, chromatophores 

3, diameter vegetative cells 22- 

26/x 

76. Spores ovoid, chromatophores 2- 


117. S.c/iung/îngensis 

22 /i 108. S. puncticulata 

76. Spores ellipsoid, chromatophores 

3-2, diameter vegetative cells 20- 

25^1 

76. Spores ovoid, chromatophores 3- 


115. S. miamiana 

25 109. S. aeqtiinoctialis 

77. Zygospores ovoid 78 

77. Zygospores ellipsoid 


etative cells 25-32 jtt no. 5. rhizopus 


vegetative cells 28-32 /^ in. 5. dictyospora 

78, Chromatophores 2-4, diameter 

vegetative cells 30-37 /a, median 

spore wall double 135 


vegetative cells 31-36 /a 112 


vegetative cells 30-45 /a i33- "^^ fiuviatilis 

79. Diameter spores usually less than 32 /x, 

2 chromatophores 1 13. 5. fossa 

79. Diameter spores between 32 and 43^1 

79. Diameter spores usually more than 43 /u. 81 

80. Median spore wall punctate or scrobiculate 82 

80. Median spore wall reticulate 83 

Chromatophores 2-3 (-4), diameter 

S. notabilis 

S. natchita 

spores 43-46 /x 

Chromatophores 3-4, diameter spores 

1 14. 5. schmidtii 

45-52 M i\G. S. smithii 

79 

80

82. Median spore wall double, outer 

SPIROGYRA 139 

wrinkled, inner punctate iiy. S. chun\ingensis 

82. Median spore wall single, finely 

scrobiculate 1 18. 5. orientalis 

83. Chromatophores 2, spores very irreg- 

ularly reticulate wo. S. rhizopus 

83. Chromatophores 2-4, regularly retic- 

ulate 1 19. 5'. subcylindrospora 

84. Zygospores ellipsoid 85 


85. Chromatophores 2-3, diameter veg- 

etative cells 34-37 M 120. iS. castanacea 

85. Chromatophores 2-3, diameter veg- 

etative cells yu. 42-48 121. S. mienningensis 


tive cells 46-52 M 122. S. shantungensis 


tive cells 50-60 /i 123. S. braziliensis 

85. Chromatophores 3-5 86 

86. Diameter vegetative cells mostly less than 55 /x 87 

86. Diameter vegetative cells mostly more than 55 /x 90 

87. Spore diameter mostly less than 54/A 88 

87. Spore diameter 48-64 /a, 4-3 (-2) chromatophores 

124. S. pulchrifigurata 

87. Spore diameter 67-72 ju,, 3-5 chroma- 

tophores 125. S. torta 

88. Median spore wall of a single layer 89 


wrinkled, inner punctate 126. S.quadrilaminata 


wrinkled, inner smooth 129. 5. subreticulata 

89. Median spore wall finely, irregularly 

reticulate, spore 38-60 /a x 64-100 /«.... 127. S.rhizobrachialis 

89. Median spore wall irregularly cor- 

rugate, spores 37-41 /A X 48-65/4 128. S. paraguayensis 

90. Fertile cells cyUndric or enlarged 130. S. minor 

90. Fertile cells inflated 91 

91. Median spore wall intricately retic- 

ulate 131. S. brunnea 

91. Median spore wall angularly punctate 132, S.scripta 

92. Fertile cells inflated 93

140 

ZYGNEMATACEAE 


93. Chromatophorcs 3 in each cell 94 

93. Chromatophorcs 3-4, diameter veg- 

etative cells 35-45 M ^M- ^- flufiatilis 

93. Chromatophorcs 3-4, diameter veg- 

etative cells 50-60 /J. 134. S. africana 


corrugate 136. 5. grossii 

94. Median spore wall granulosc î7- 

^- ovigera 

95. Median spore wall reticulate, brown, 

diameter spore 42-54 m 129. 5. sttbreticulata 

95. Median spore wall scrobiculate, yel- 

low, diameter spore 50-65 /^ 13S. 5'. novae-angliae 


96. Zygospores ovoid loi 

97. Median spore wall verrucose 98 

97. Median spore wall reticulate 99 

97. Median spore wall pitted, scrobiculate, or punctate 100 

98. Chromatophorcs 4-8, diameter 

spores 89-100 /A 274. S. verrucosa 

98. Chromatophorcs 2-3, diameter 

spores 48-521". 120. S. castanacea 

98. Chromatophorcs 2, diameter 

spores 54-60 iti. 123. 5. braziliensis 


spores 105-120 M 140. S. verruciilosa 

99. Diameter spores 55-66/x, fertile cells 

inflated, chromatophorcs 3-5 131- "^^ hrimnea 

99. Diameter spores 65-83 /x, fertile cells 

cylindric, chromatophorcs 3-4 141. 5. malmeana 

99. Diameter spores 73-90 /x, fertile cells 

cylindric, chromatophorcs 5-10 139. S. anomala 


spores 42--60JU 142. 5'. propria 

100. Chromatophorcs 4-6(-8), diam- 

eter spores 87-108 /x 143. S. trachycarpa 

luo. Chromatophorcs (3-)4-5(-7)> di- 

ameter spores 64-74/1 T45. 

loi. Fertile cells cylindric, chromato- 

>!>'. pitnctiilata 

phorcs 4 146. 5. cylindrospora 

loi. Fertile cells cylindric or enlarged, 

chromatophorcs 5 140. 5. verruciilosa

loi. Fertile cells cylindric, chromato- 

SPIROGYRA 14 T 

phores 6-7 144. S. ghosei 

101. Fertile cells enlarged or inflated, chromatophores 3-8 102 

102. Diameter vegetative cells less than 85 /x 103 

102. Diameter vegetative cells more than 85 /^ 104 


chromatophores 3-4 i34- '^- ajricana 

103. Vegetative cell diameter 56-71 a^, 

chromatophores 3-5 iji- '^^ brunnea 

103. Vegetative cell diameter 66-72/^, 

chromatophores 6-8 147. 5. echinospora 

103. Vegetative cell diameter 70-85 /-i, 

chromatophores 5-8 14S. S. diluta 

104. Median spore wall echinate, chromatophores 

4-7 149. S. echinata 

104. Median spore wall reticulate, 

chromatophores 4-6 150. S. reinhardii 

104. Median spore wall reticulate- 

echinate, chromatophores 8-10.. 151. S.hunanensis 

SPORES LATERALLY COMPRESSED 

CHROMATOPHORES, TWO OR MORE 

105. Spores compressed-ellipsoid, 120-140/^ 

X 145-255 ^t 175. S. crassoidea 

105. Spores compressed-ovoid 106 

105. Spores compressed-spheroid (lenticular) 108 

106. Median spore wall smooth, chromatophores 

8-9 165. S. jassiensis 

106. Median spore wall pitted 107 

106. Median spore wall verrucose, 

chromatophores 11-16 176. S. rectispira 


chromatophores 6-12 164. S. formosa 


chromatophores 6-12 167. S. crassa 


108. Median spore wall variously ornamented 112 

109. Diameter vegetative cells less than /a, 50 chromatophores 2-4 no 

109. Diameter vegetative cells more than 50/1, chromatophores 

3-10 

no. Vegetative cell diameter 22-24 /t, 

chromatophores 2-4 154. 5. sinensis 

Ill

142 

ZYGNEMATACEAE 

no. Vegetative cell diameter 32-36/1, 

chromatophores 3-4 i55- '^- jranlilirJiana 

no. Vegetative cell diameter 40-50 m, 

chromatophores 3-4 156. 5. pellucida 

no. Vegetative cell diameter 29-40 ju., 

chromatophores 4-6 i57- '^^ colltgata 

no. Vegetative cell diameter 40-45/1, 

chromatophores 4-7 267. S. subpelliicida 

ni. Diameter vegetative cells 50-80/^, 

chromatophores 3-8 158. 5. majuscula 

III. Diameter vegetative cells yo-iio ij., 

chromatophores 8-9 159. 5. submaxima 

n I. Diameter vegetative cells 145-155/^, 

chromatophores 7 160. .S". glabra 

III. Diameter vegetative cells n3-i25/j., 

chromatophores 5-6 265. S. peipingensis 

112. Vegetative cell diameter 32-40 /t, 

median spore wall punctate 266. S. sphaerocarpa 


median spore wall irregularly 

pitted 161 . 5. bellis 

112. Vegetative cell diameter 80-1 18 /a 113 

112. Vegetative cell diameter 1 18-200 m 114 

113. Chromatophores 6-8, median spore 

wall irregularly reticulate 162. 5. moebii 

n3. Chromatophores 9-13, median spore 

wall verrucose 163. S. oblata 

iiT,. Chromatophores 7-10, median spore 

wall pitted, tubes formed by male cells 177. S. hydrodictya 

\i},. Chromatophores 7-10, median spore 

wall reticulate-verrucose 168. 5. manoramae 

114. Diameter vegetative cells mostly less than 150/1 115 

114. Diameter vegetative cells mostly more than 150/1 116 

n5. Diameter vegetative cells 116-132/^1, 

8-9 chromatophores, median spore 

wall smooth 165. S. jassiensis 

115. Diameter vegetative cells 1 18-130 /i, 


wall verrucose 169. S. jatobae 

11^. Diameter vegetative cells 1 18-140 /i, 


wall reticulate lyo. S. maxima


about 8 chromatophores, median spore 

SPIROGYRA 143 

wall verrucose 171. 5. heeriana 


170 /A, 6-7 chromatophores 172. 5. crassiuscula 


200 jn, 6-7 chromatophores i73- '^- tnegaspora 


162 /x, 9-10 chromatophores 174. 

iS*. lenticularis 

CONJUGATING TUBES FORMED BY THE MALE GAMETANGIA; SHORT 

FERTILE CELLS OFTEN ALTERNATING SINGLY, OR IN PAIRS, 

WITH LONG STERILE CELLS 

117. Diameter vegetative cells less than 30 /^ 118 

117, Diameter vegetative cells between 30 jn and 40 /a 125 

117. Diameter vegetative cells more than 40 /x 128 


1 18. Zygospores ovoid 124 

119. Diameter vegetative cells less than 15 a"- 120 

119. Diameter vegetative cells 15/^ to 24/i. 121 

119. Diameter vegetative cells more than /j. 24 123 

120. Median spore wall smooth 180. 5. liana 

120. Median spore wall coarsely punc- 

tate 181. S. prescottii 

120. Median spore wall reticulate to 

punctate 179. 5. taylorii 

121. Spores with median wall smooth 122 

121. Spores with median wall coarsely 

punctate 183. S. collinsii 

121. Spores with median wall irregularly 

pitted 185. S. sirogonioides 

121. Spores with median wall reticulate. . . 186. S. lushanensis 

121. Spores with median wall finely scro- 

biculate 271. S. sibirica 

122. Fertile cells inflated on the con- 

jugating side 18. 5. gibberosa 

122. Fertile cells inflated both sides.. 182. S.chenii 

123. Median spore wall coarsely punctate, 

diameter vegetative cells 24-30 a^ 184. S. punctata 

123. Median spore wall irregularly retic- 

ulate, diameter vegetative cells 27-33/^ 187. S.esthonica

144 

ZYGNEMATACEAE 

124. Median spore wall punctate, diameter 

vegetative cells 27-30 /a. . . 189. S. punctijormis 


tate, diameter vegetative cells 

18-22/X 183. S. collinsii 


tate, diameter vegetative cells 

13-14/^ 181. 6'. prescottii 

125. With I chromatophore (rarely 2 in some cells) 126 

125. With 2 or ^ chromatophores (rarely i) in each cell 127 

126. Median spore wall smooth, gam- 

etangia strongly reflexed 190. S. reflexa 

126. Median spore wall punctate 191. 5. micropunctata 


reticulate, diameter vegetative 

cells 27-33 /x 187. S. esthonica 

126. Median spore wall scrobiculate . . 188. S.suomiana 

127. Spores ellipsoid to ovoid, median wall 

punctate 1 14. 5". schmidtii 

127. Spores ovoid, outer median wall cor- 

rugate, inner finely reticulate 192. 6\ corrugata 

128. Chromatophore i in each cell 129 



129. Median spore wall smooth, diameter 

vegetative cells 40-45 m n)6. S. visenda 

129. Median spore wall smooth, diameter 

vegetative cells 53-56/A 197. S. Iiungarica 

129. Median spore wall punctate 193. S. rugulosa 

130. Chromatophores 3, median spore 

wall irregularly corrugate 136. S. grossii 

130. Chromatophores 2-4, median 

spore wall areolatc 194. S. wabashensis 

130. Chromatophores 3-5, median 

spore wall reticulate 178. S. texensis 

131. Chromatophores 5, spores ovoid 195. S.conspicua 

131. Chromatophores 7-10, spores lentic- 

ular lyy. S. hydrodictya 

DIVISION WALLS SEMIREPLICATE 

132. An infold extending halfway around the wall and alter- 

nating in position in adjoining cells 133

SPIROGYRA 145 

133. Reproducing by aplanospores 198. S. narcissiana 

133. Reproducing by zygospores 199. S. undulisepta 

DIVISION WALL REPLICATE 

134. A circular infold on the end walls of most cells 135 

135. Tubes formed by both gametangia 136 

135. Tubes apparently formed by the male gametangia 159 

136. With I chromatophore in each cell, rarely 2 in some cells 137 

136. With usually more than i chromatophore in each cell. 167 

REPLICATE END WALLS 



137. Fertile cells fusiform-inflated 148 

137. Fertile cells cylindrically ("quadrately") inflated 158 



139. Median spore wall smooth, and outer wall smooth 140 

139. Median spore wall smooth, but inner 

layer of outer wall scrobiculate 236. S. venusta 

139. Median spore wall reticulate 222. S. dentireticulata 

140. Diameter vegetative cells less than 24 i^, 141 

140. Diameter vegetative cells between 24 /x and 40 /^ 142 


than 40 /A 233. S. tjibodensis 

141. Zygospores 22-26 (-32) ;u, x 51-103 /a.. 228. S.arta 

141. Zygospores 30-36 /a x 55-1 10 /a, some 

fertile cells inflated 226. S. spreeiana 

141. Zygospores 25-35^1 x 48-86 ju, sterile 

cells inflated 229. S. tumida 

142. Zygospores 32-42/1 x 80-122 /a, 

outer wall thick, lamellate 231. 5". lamellosa 

142. Zygospores 30-33/1 x 60-82/1, 

outer wall thin 232, S. laxa 

142. Zygospores 35-46/1 x 61-106/1, 

usually ovoid 208. S. semiornata 

143. Median spore wall smooth, outer also smooth 144 

143. Median spore wall smooth, outer wall of 2 layers, of which 

the inner is transparent, scrobiculate 145 

143. Median spore wall granulate, outer 

wall of 2 thin layers 224. S. microgranulata


144. Zygospores 21-30/x x 30-So/i 207. S.weheri 

144. Zygospores 35-46/1 x 61-106^... 208. S.semiornata 

145. Diameter vegetative cells less than :;5/x 146 

145. Diameter vegetative cells more than 35 m 147 

146. Vegetative cell diameter 25-27 /a. 236. S.venusta 

146. Vegetative cell diameter 28-34/^. 237. S.protecta 

147. Cell diameter 36-40 /x 238. S. cleveana 

147. Cell diameter 42-56/1 239. 5. denticidata 

148. Vegetative cell diameter usually less than 20/1 149 

148. Vegetative cell diameter usually more than 20/1 152 



150, Diameter vegetative cells 8-13/Ji. 200, S.tenuissima 

150. Diameter vegetative cells 15-20/1 201. S.inflata 

151. Diameter vegetative cells 11-13M, fer- 

tile cells inflated 21:,. S. rugosa 

151. Diameter vegetative cells 13-17/s fusi- 

form-inflated fertile cells 215. S. {intsamoensis 

151. Diameter vegetative cells 16-20 /

SPIROGYRA 147 


wrinkled, inner smooth 262. S. jaoi 


i8-24iU. times as long 218. S. groenlandica 


3-10 times as long 219. S. quadrata 


TUBES FORMED BY MALE GAMETANGIA 



160. Zygospores mostly ellipsoid 161 

160. Zygospores mostly ovoid, median 

wall areolate 225. S. laxistrata 

161. Median spore wall single, foveolate. . 214. S.foveolata 

161, Median spore wall double, wrinkled 

and reticulate 223, S. lambertiana 

162. Fertile cells fusiform-inflated both sides 163 

162. Fertile cells cylindrically inflated 165 

162, Fertile cells inflated mostly on the conjugating side 166 

163. Diameter vegetative cells 16-19 /x 203, S. pseudospreeiana 

163. Diameter vegetative cells 18-25/1 164 

163. Diameter vegetative cells 28-39/1 211. S. chuniae 

164. Zygospores 24-28 /a x 46-52/1. 

. . . 227. S.tsingtaoensis 

164. Zygospores 30-36/1 x 55-100/1... 226. S.spreeiana 

165. Diameter vegetative cells 13-16/1 202. S. cylindrica 

165. Diameter vegetative cells 18-21 /i 204. S. pascheriana 

166. Vegetative cell diameter 17-25/1, 

spores ellipsoid 230. S. croasdaleae 


spores ovoid 210. S. grevilleana 


spores ellipsoid 205. S. hopeiensis 


USUALLY TWO OR MORE CHROMATOPHORES 

167. Median spore wall outwardly smooth (punctate in No. 212) 168 

167. Median spore wall not smooth (yellow to dark brown) .... 177 

168. Fertile cells cylindric or enlarged, all spore walls smooth 169 

168. Fertile cells inflated 172

148 

ZYGNEMATACEAE 




etative cells 29-32 /x 275. S. marchica 


vegetative cells 28-33/1 244. S. gratiana 


vegetative cells 37-40 /a 245. S. proavita 


vegetative cells 42-58 /a 246. S. transeaiiiana 

171. Zygospores ovoid, diameter 29-32 /x, 

2 chromatophores 275. S. marchica 

171. Zygospores ovoid, diameter 26-29/1, 

2 chromatophores 241. S. tolosana 

171. Zygospores ovoid, about 40 /a x 82- 

86 /A, 2-3 chromatophores 245. S. proavita 

171. Zygospores ovoid, diameter 45-50 /^ 

2 chromatophores 243. S. hartigii 



173. Chromatophores 2 to 4, receptive gam- 

etangia cylindrically inflated 247. S. rectangularis 

17^. Chromatophores i or 2, second outer 

spore wall scrobiculate 240. S. areolata 



175. Chromatophores (i-)2, diameter zygospores 

42-52^1, median wall dotted. 212. S.incrassata 

175. Chromatophores 2, diameter zygospores 

39-48^1, median wall smooth. . 242. S.hassallii 

175. Chromatophores 2 or 3, diameter zygospores 

60-64 /^ 25'^- ^- 'i'^^^S^ 

176. Chromatophores 3, diameter zy- 

gospores 40-48 /i 248. iS". insignis 

176. Chromatophores 3 or 5, diameter 

zygospores 45-60 /u, 249. S. fallax 


TWO OR MORE CHROMATOPHORES, MEDIAN SPORE WALL NOT SMOOTH 

177. Zygospores usually ellipsoid 178 

177. Zygospores usually ovoid 181

SPIROGYRA 149 

178. Chromatophores i to 3 179 

178. Chromatophores 2 to 4 180 

179. Median spore wall single 254. S. nawashini 

179. Median spore wall double 255. S. tetrapla 

180. Chromatophores (2-) 3-4, spore 

diameter 45-75 M, aculeate-retic- 

ulate 252. S. inconstans 

180. Chromatophores 3-4, reticulate- 

spinose 251. S. acanthophora 

180. Chromatophores 2-4, spore diam- 

eter 52-62 /a, mammillate-aculeate 253. S.borysthenica 

180. Chromatophores 2, spore diam- 

eter 42-50 Ai, median wall double 264, S.crassispina 

181. Chromatophores 2 182 

181. Chromatophores (i-)2-3, diameter 

spore At, 45-60 median wall double. . . 256. S. reticulata 

181. Chromatophores 4-3, diameter spore 

52-71 

ju., median wall double 258. S. crassivallicularis 

182. Spores, diameter 39-45 fi, median 

wall single, reticulate 257. S. regularis 

182. Spores, diameter 45-55 M, median 

wall double, inner granulate 259. S. granulata 

182. Spores, diameter 51-55/^, median 

and outer walls double 260. S. quinquelaminata 

182. Spores, diameter 46-68 a^, median 

wall double, reticulate 261. S. pseudogranulata 

REPRODUCTION WHOLLY OR MOST COMMONLY BY APLANOSPORES 

183. End walls plane 184 

183. End walls semireplicate, diameter veg- 

etative cells i2-i/\fj- 198. S. narcissiana 

183. End walls replicate, diameter vegeta- 

tive cells 24-28 Ai 234. S. articulata 

184. With I chromatophore 185 

184. With 2 or more chromatophores 186 

185. Sporangia cylindric, aplanospores 

ovoid 31- '^- oltmannsii 

185. Sporangia enlarged or slightly inflated 29. S. mirabilis 

185. Sporangia and sterile cells often in- 

flated 38. 'S. aplanospora 

186. With 2 to 3 chromatophores in 

each cell, spores ellipsoid 65. 5. maravillosa

150 

ZYGNEMATACEAE 

186. With 6 to 8 chromatopliores in 

each cell, spores ellipsoid 85. 5. wrightiana 

186. With 5 chromatophores in each 

cell, spores lenticular \(£. S. azygospora 

Aplanospores have been found together with zygospores in some 

collections of the following species: S. catenaeform is, S. denticiilata, 

S. farlowii, S. gratiana, S. groenlandica, S. hyalina, S. inflata, S. juer- 

gensii, S. rnajuscula, S. neglecta, S. obovata, S. parvula, S. pratensis, 

S. protecta, S. quadrata, S. qiiinquelatninata, S. reftexa, S. sahnii, 

S. semiornata, S. spreeiana, S. sitbpapidata, S. tenuissima, S. tjibodensis, 

S. varians, S. weberi. 


SPECIES WITH PLANE END WALLS 


1. SpmoGYRA COMMUNIS (Hassall) Kiitzing 1849. Species Algarum, 

p. 439. Hassall. 1844. History of British Freshwater 

Algae, p. 148, PI. 28, Figs. 5-6. 

Vegetative cells i8-26iu, x ^5-90 m with plane end walls; i chro- 

matophore, making 1.5 to 4 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells cyUndric, rarely enlarged; 

zygospores ellipsoid, 19-26 m x 36-78 /a; median spore wall yellow, 

smooth. (PI. XXI, Fig. i.) 

Jersey. 

United States: Colorado to Texas; east to Massachusetts and New 

Reported from all the continents, also New Caledonia. 

Distinguished from other species with similar vegetative cells and with 

approximately the same dimensions by the smooth ellipsoid spores, the 

cylindric fertile cells, and the absence of inflated sterile cells. Found hybridizing 

with S. varians at Charleston, Illinois. The resulting segregates were 

also present. 

2. Spirogyra intorta Jao 1935. Sinensia. 6, p. 590, PI. 5, Fig. 58. 

Vegetative cells 25-29 /j. x 60-1 /x, 

83 with plane end walls; filaments 

generally curved to spiral; i chromatophore, making 3.5-6 turns in the 

cell; conjugation scalariform and lateral; tubes formed by both gam- 

etangia; fertile cells cylindric, sometimes slightly enlarged; zygospores 

ellipsoid, with pointed ends, 22-29/i x 4i-68;ti; median spore wall 

yellow, smooth. (PI. XXI, Fig. 2.) 

United States: Texas, Johnson City, April 24, 1938 (Taft Coll.). 

China, Szechwan.

SPIROGYRA 151 

3. Spirogyra juercensii Kiitzing 1845. Phycologia Germanica, 

p. 222. 

Vegetative cells 24-30 /a x 60-125 /a, with plane end walls; i chromatophore, 

making 2 to 4 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells cylindric or enlarged 

toward the middle (to 34^); zygospores and aplanospores eUipsoid, 

28-33 M X 50~75^-; median spore wall yellow, smooth. (PI. I, Fig. i; 

PI. XXI, Fig. 3.) 

United States: California; from Wisconsin, Iowa, and Texas to the 

east coast. 

Widely distributed in Europe; South America; Australia. 

Distinguished from S. longata by the ellipsoid spores. Sometimes at 

maturity the stretching of the fertile cell wall shortens that end of the conjugating 

tube, and the tube has the appearance of having been formed by 

the male cell as in S. punctijormis and S. micropunctata. From the former 

it is distinguished by the ellipsoid, smooth spores; from the latter by the 

smaller size and smooth spore wall. In a collection from Mississippi cylin- 

drically inflated akinetes with thick walls were present together with zygo- 

spores. The dimensions of the akinetes varied from 48-60 ju x 108-140 /.i. 

(PI. I, Fig. I.) 

4. Spirogyra singularis Nordstedt 1880. Bot. Notiser 1880. 

p. 118. Wittrock and Nordstedt Algae Exsiccatae, No. 361. 

Vegetative cells 29-39^1 x 60-240 /x, with plane end walls; i chromatophore, 

making 3 to 7 turns; conjugation scalariform; tubes formed 

by both gametangia, fertile cells cylindric, rarely enlarged; zygospores 

elHpsoid, 27-36 jn x 46-70 jU,; median spore wall yellow, smooth. (PI. XXI, 

Fig- 4-) 

United States: Michigan and Texas, to the east coast. 

Described from New Zealand; reported from Finland; South Africa; 

China; Brazil. 

Distinguished from S. longata by the ellipsoid spores. In all specimens 

seen the chromatophores were narrow and the spirals very open. 

5. Spirogyra silvicola Britton 1943. Amer. Jour. Bot. 30, p. 799, 

Fig. I. 

Vegetative cells 32-42 m x 63-267 ju., with plane end walls; i chro- 

matophore, making 1.5 to 3 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; receptive gametangia cylindric or 

slightly enlarged; zygospores ellipsoid to cylindric-ovoid, 36-43 /a x 

56-103 /a; all walls smooth; median wall yellow or brown at maturity. 

(PL XXI, Fig. 7.) 

United States: Illinois, Somme Forest, Cook County, May 15, 1938 

(Britton Coll.); Texas, Austin (Taft Coll.). 

Vegetative cells similar to those of S. singularis; zygospores much larger.

152 

ZYGNEMATACEAE 

6. Spirogyra condensata (Vaucher) Kiitzing 1843. Phycologia 

Generalis, p. 279. 

Vegetative cells 45-^)0/1 x 45-1 20 m, with plane end walls; i chro- 

matophore, making .5 to 4 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells cylindric or slightly 

enlarged; zygospores ellipsoid, 34-3^/^ x 50-75 ju; median spore wall 

yellow, smooth. (PI. XXI, Fig. 11.) 

United States: Wisconsin and Kentucky; eastward to Massachusetts 

and New Jersey, 

Widely distributed in Europe; reported from South America. 

Characterized by its short cells and closely spiraled chromatophores. 

Sterile cells sometimes inflated. 

7. Spirogyra variformis Transeau 1938. Amer. Jour. Bot. 25, 

pp. 526-27. 

Vegetative cells 43-50M x (70-) 108-140 (-200) m with plane end 

walls; I chromatophore, making 2 to 5 turns in the cell; conjugation 

scalariform; tubes formed by both gametangia and widest at the mid- 

dle; some sterile cells inflated to 72-ioo/t; fertile cells mostly cylindric 

but sometimes enlarged or inflated; zygospores ellipsoid or ovoid, 

45-54 /x X 58-90 M, rarely spherical, 52-60 /u. in diameter; median wall 

brown, smooth. (PI. XXI, Figs. 9-10.) 

Africa, Cape Town (Stephens Coll.). 

8. Spirogyra gracilis (Hassall) Kiitzing 1849. Species Algarum, 

p. 438. 

Vegetative cells 16-24/x x 50-ioo/x, with plane end walls; i chromatophore, 

making .5 to 4 turns; conjugation scalariform; tubes formed 

by both gametangia; fertile cells inflated, mostly on the conjugating 

side; zygospores ellipsoid with rounded ends, 23-30 ju. x 40-65 i^^; median 

spore wall yellow-brown, smooth. (PI. XXI, Fig. 5.) 

chusetts. 

United States: Colorado; Texas; Missouri; Michigan; Ohio; Massa- 

Widely distributed in Europe; reported also from China and Siam. 

9. Spirogyra fragilis Jao 1935. Sinensia. 6, p. 590, PI. 6, Fig. 64. 

Vegetative cells 24-29 jt^ x 54-160/11, with plane end walls; chromatophore 

I (rarely 2), making 1.5-6 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells slightly inflated, usually a Uttlc 

more on the conjugating side; the female gametangia often separate 

from each other after conjugation; zygospores ellipsoid with more or 

less rounded ends, 22-38 /li x 36-67/1; median spore wall yellow, smooth. 

(PI. XXI, Fig. 6.) 

United States: Texas, Johnson City, April 24, 1938 (Taft Coll.).

SPIROGYRA 153 


The separation of the sporiferous cells is an unusual feature but also 

occurs frequently in S. parvula. 

10. Spirogyra teodoresci Transeau 1934. Ohio Jour. Set. 34, 

p. 420. (=S. varians var. minor) Teodoresco. Beih. Bot. 

Zentralbl. 21, abt. 2. 1907. 

Vegetative cells iu. 24-30 x 42-90 /a, with plane end walls; i chromatophore, 

making i to 6 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells strongly inflated on the 

conjugating side; zygospores elHpsoid, 26-33 /a ^ 45~55/^5 median spore 

wall smooth, yellow. (PI. XXI, Fig. 8.) 

chusetts. 

United States: Iowa; Illinois; Michigan; Kentucky; New York; Massa- 

Rumania; China, Nanking, Peiping (Li Coll.). 

Probably included in many records of S. varians, from which it is 

distinguished by its smaller dimensions throughout, 

11. Spirogyra pseudovarians Czurda 1930. Beih. Bot. Zentralbl. 

47, p. 32. 

Vegetative cells 36-^9 M x 35-75 M, with plane end walls; chromatophores 

i (rarely 2); conjugation scalariform; tubes formed by both 

gametangia; fertile cells swollen, mostly on the conjugating side; zygo- 

spores ellipsoid, 33-37 it^ x 47-57 m; outer spore wall thick, transparent, 

scrobiculate; median spore wall reddish-brown, smooth; sterile cells 

more or less swollen. (PI. XXI, Figs. 12-14.) 

Czechoslovakia; Austria. 

Distinguished by the heavy, transparent, shallow-scrobiculate outer wall. 

12. Spirogyra varians (Hassall) Kiitzing 1849. Species Algarum, 

p. 439. Includes S, woodsii Czurda and S. varians 

(Kiitzing) Czurda. 

Vegetative cells (28-) 30-40 ju, x 30-120 /a, with plane end walls; i 

chromatophore, with i to 5 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells usually inflated on the 

conjugating side only, rarely on both sides; some of the sterile cells 

usually inflated; zygospores mostly ellipsoid, usually some of them 

ovoid and very rarely globose, 32-40 ;u, x 50-100/^; median spore wall 

yellow, smooth; aplanospores similar. (PI. XXII, Fig. i.) 

Generally distributed in the United States, including Alaska. 

Also reported from British Columbia to Newfoundland. 

Widely distributed in Europe, Asia, Africa, and Australia. 

A highly variable species, but usually readily identified by the combi-

154 

ZYGNEMATACEAE 

nation of dimensions, unilaterally inflated sporiferous cells, and the inflated 

sterile cells. Has been found hybridizing with S. porttcalts, S. longata, and 

S. communis and producing a variety of segregates. Due to the occurrence 

of haploid segregates and the wide overlapping of cell and spore dimensions, 

it has not been found advisable to separate the variants further. 

13. Spirogyra bicalyptrata Czurda 1930. Beih. Bot. Zentralbl. 

47, p. 31. 

Vegetative cells 36-59^1 x 60-110/^, with plane end walls; chromatophore 

i (rarely 2); conjugation scalariform; tubes formed by both 

gametangia; fertile cells swollen on the conjugating side; zygospores 

ellipsoid, 31-34/^ x 55-70 m; median spore wall brown, smooth, with 

dark brown polar thickenings. (Pi. XXII, Fig. 2.) 

Czechoslovakia; Austria; Greece. 

Distinguished from S. varians by the occurrence of 2 chromatophores 

in some cells and the brown polar thickening of the median wall. A similar 

local polar thickening sometimes occurs in scattered spores of other species. 

14. Spirogyra circumlineata Transeau 1914. Amer. Jour. Bot. 

l,p.293. 

Vegetative cells ( ^58-) 40-48 /x x 1 20-240 /m, with plane end walls; 

I chromatophore, slender, making 4 to 8 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells inflated on the conju- 

gating side only; zygospores ellipsoid, 40-50 m x 70-125 /x; median spore 

wall yellow-brown, smooth; suture more or less prominent. (PI. XXII, 

Fig- 3-) 

United States: Iowa; Illinois; Michigan; Ohio. 

Distinguished from S. varians by the larger dimensions, the slender 

chromatophore making a larger number of turns, the distinct suture encir- 

cling the spore, and the absence of inflated sterile cells. 

15. Spirogyra supervarians Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 208. 

Vegetative cells 50-57 /j. x 50-1 44 m; 

i chromatophore; cells with 

plane end walls; conjugation scalariform; tubes formed by both gam- 

etangia; receptive gametangium inflated on the inner side; zygospores 

ellipsoid, small in proportion to the gametangia, 35-40 m x 54-74 m; 

median spore wall smooth, yellow. (PI. XXII, Fig. 7.) 

Africa, Cape Flats (E. Stephens Coll.). 

Similar to S. varians in appearance, but wiih much larger dimensions 

throughout, and without inflated sterile cells. 

16. Spirogyra fennica Ccdercreutz 1924. Acta Soc. pro Fauna et 

Flora Fennica. 55 (2), p. 4. 

Vegetative cells 15-19M x 60-260^, with plane end walls; i chro-

SPIROGYRA 155 

matophore; conjugation scalariform; tubes formed by both gametangia; 

fertile cells shortened and inflated to 34-39^1; zygospores ellipsoid, 

24-31 ju, X 45-55/^; median spore wall yellow-brown, smooth. (PL XXII, 

Fig- 4-) 

Finland; China, Szechwan; South Africa. 

Distinguished from S. parvula by the much smaller vegetative cells; and 

from S. pratensis by the absence of cells with 2 chromatophores, and by the 

absence of globosely inflated sterile cells. 

17. Spirogyra parvula (Transeau) Czurda 1932. Siisswasserflora 

Mitteleuropa. 9, p. 170, Fig. 174. 

Vegetative cells 20-24 /x x 50-105^1, with plane end walls; i chromatophore, 

making i to 6 turns; conjugation mostly lateral, sometimes 

scalariform; tubes formed by both gametangia; fertile cells inflated up 

to 37 /x, often separating from one another but held in place by the male 

filament; zygospores ellipsoid, 20-27 /x ^ 40-60 a^; median spore wall 

yellow-brown, smooth; aplanospores similar in size and shape to zygo- 

spores. (PI. XXII, Figs. 5-6.) 

United States: Iowa and Texas, to New York. 

Norway; India; China. 

18. Spirogyra gibberosa Jao 1935. Sinensia. 6, p. 586, PI. 4, Figs. 

50-51. 

Vegetative cells 19-21^1 x ^^-10^^, with plane end wall; i chro- 

matophore, making 2 to 8 turns in the cell; conjugation scalariform, 

sometimes lateral; tubes formed by the male gametangia; fertile cells 

inflated on the conjugating side, to 45 /i, often separating from each 

other as the spores mature; zygospores ellipsoid with more or less 

pointed ends, 22-29 /a x 38-50 /x; median spore wall smooth, yellow at 

maturity. (PI. XXII, Figs. lo-ii.) 


Separation of the sporiferous cells after conjugation is similar to that 

frequently seen in S. parvula. Placed here because of doubt that tubes are 

formed by the male gametangia. This may be only apparent, because of 

subsequent enlargement of the receptive gametangia. 

19. Spirogyra borgeana Transeau 1915. Ohio Jour. Set. 16, p. 23. 

Vegetative cells ju- 30-35 x 50-200 /x; with plane end walls; i chromatophore, 

making 1.5 to 5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated on the outer side, 

cylindric on the conjugating side; zygospores ellipsoid, /it 30-40 x ;ix; 54-70 

median spore wall yellow, smooth. (PI. XXII, Fig. 8; PI. XXIII, 

Fig. 16.) 

United States: Iowa; Illinois; Michigan; Indiana; Ohio.

156 

Czechoslovakia; Tibet; China. 

ZYGNEMATACEAE 

Figure 16 on Plate XXII I depicts an instance in which the terminal 

cells of 2 adjacent filaments conjugated through the end walls with 2 adjoin- 

ing receptive gametangia of a third filament. The specimen was collected 

near Douglas Lake, Michigan. Named for the late Oskar F. A. Borge of 

Stockholm, Sweden. 

20. Spirogyra calcarea Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 226. 

Vegetative cells 37-42 /x x 40-120/j., with plane end walls; i chromatophore, 

making 2 to 5 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; receptive gametangium inHated only 

on the outer side; zygospores ellipsoid, 40-55 /a x 58-80 /a; median spore 

wall smooth, yellow. 

United States: Alabama, Birmingham, sinkholes in limestone. 

Similar in form to S. borgeana but larger in all dimensions. 

21. Spirogyra bullata Jao 1935. Sinensia. 6, p. 588, PI. 4, Fig. 55. 

Vegetative cells 19-22/x x 41-83;", with plane end walls; i chromatophore, 

making 1.5-5.5 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; sterile cells buUate up to 64 m in 

diameter and occurring in rows up to 25 cells long; fertile cells cylindric 

or slightly enlarged; zygospores ellipsoid, 22-291". x 31-35 (-51)^; spore 

wall smooth, yellow at maturity. (PI. XXII, Fig. 13.) 


Differs from S. pratensis in the shorter spores and absence of inflated 

fertile cells. 

22. Spirogyra pratensis Transeau 1914. Amer. Jour. Bot. 1, 

p. 292. 

Vegetative cells 17-20 /a x 80-240 jU, with plane end walls; i chromatophore 

(rarely 2), making i to 8 turns; reproducing commonly by 

both zygospores and aplanospores; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells enlarged or fusiform- 

inflated to 38 /ti; sterile cells cylindric or inflated up to 90 m in diameter; 

spores in most cells ellipsoid, in others ovoid, or cylindric-ovoid, 

2^-^6iJi X 50-70^1; median spore wall yellow, smooth. (PI. I, Fig. 7; 

PI. XXII, Figs. 14-18.) 

United States: Iowa; Wisconsin; Arkansas; Illinois; Michigan; Kentucky; 

Ohio. 

China, Peiping (Jao Coll.), Nanking (Li Coll.). 

The occurrence of globoscly swollen sterile cells and the presence of 

lateral and scalariform conjugation together with aplanospore formation in 

most collections and sometimes in a single pair of filaments give character 

to this species.

SPIROGYRA 157 

23. Spirogyra affinis (Hassall) Petit 1880. Les Spirogyres des 

environs de Paris, p. 18, PL 3, Figs. 13-14. 

Vegetative cells 25-30 /x x 35-90 /a, with plane end walls; i chromatophore, 

making i to 3.5 turns; conjugation lateral and scalariform; 

tubes formed by both gametangia; fertile cells globosely inflated; sterile 

cells not inflated; zygospores ellipsoid, 28-33 /a ^ 30-50 /"> median spore 

wall yellow, smooth. 

United States: Michigan; Alaska. 

Widely reported from Europe; Jamaica; China, Kiangsi. 

24. Spirogyra catenaeformis (Hassall) Kiitzing 1849. Species 


Vegetative cells 24-32 /a x 50-135 /a, with plane end walls; i chromatophore, 

making i to 6 turns; reproduction by both zygospores and 

aplanospores; conjugation scalariform and lateral; tubes formed by 

both gametangia; fertile cells enlarged or inflated, fusiform, sterile cells 

also inflated; zygospores and aplanospores ellipsoid, ju. 27-33 ^ 55-90 A*-; 

median spore wall yellow, smooth. (PI. XXII, Fig. 12; PI. XXIV, 

Fig. 16.) 

United States: Generally distributed throughout. 

Widely distributed in Europe; reported from China, India, and from 

East and South Africa. 

Distinguished from S. affinis by the longer vegetative cells and the 

greatly inflated sterile cells; from S. suecica by the symmetrical fusiform 

inflation of the fertile cells and the ellipsoid spores; from S. subsalina by the 

yellow spores, generally smaller dimensions, and the less marked inflation 

of the fertile cells. 

25. Spirogyra subsalina Cedercreutz 1924. Acta Soc. pro Fauna 

et Flora Fennica. 55 (2), p. 4, Fig. 2. 

Vegetative cells 28-38 /x x 70-190 m, with plane end walls; i chro- 

matophore, making 2 to 4.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated to 49-56 /j.; zygospores 

ellipsoid, 28-38 /a x 42-76 /i-; median spore wall brown, smooth. (PL 

XXII, Fig. 9.) 

United States: Mississippi, Natchez, April, 1925. 

Finland. 

26. Spirogyra flavescens (Hassall) Kiitzing 1849. Species Algarum, 

p. 438. 

Vegetative cells 10-14^1 x 30-50 /x, with plane end walls; i chromatophore, 

making i to 3 turns; conjugation scalariform; tubes formed 

by both gametangia; fertile cells inflated; zygospores ovoid, i". 20-23 x 

25-40 /a; median spore wall yellow, smooth. (PL XXIII, Fig. i.)


United States: Michigan; Massachusetts; Florida. 

Widely distributed in Europe; reported from Australia. 

27. Spirogyra subsalsa Ki'itzing 1845. P/iycologia Germanica, 

p. 222. 

Vegetative cells 22-26 /n x 35-100/1, with plane end walls; i chromatophorc, 


largely by the male gametangia, fertile cells inflated; zygospores ovoid, 

18-27/t X 30-52/1; median spore wall yellow-brown, smooth. (PI. XXIII, 

Fig. 2.) 

United States: Wisconsin (Prescott Coll.); Florida. 

Sweden; Holland; France; Czechoslovakia; Java. 

28. Spirogyra paludosa Czurda 1932. Siisswasserflora Mittel- 

europa. 9, p. 167, Fig. 170. 

Vegetative cells 18-20/j. x /t, 55-78 with plane end walls; i chromatophore; 

conjugation scalariform; tubes formed by both gametangia; 

fertile cells somewhat swollen; sterile cells cylindric; zygospores ovoid, 

24M X 46-48M; median spore wall golden-brown, smooth. (PI. XXIII, 

Fig- 3-) 

Czechoslovakia. 

29. Spirogyra mirabilis (Hassall) Kiitzing 1849. Species Algarum, 

p. 438. 

Vegetative cells 23-29 yu. x 70-200 m, with plane end walls; i chro- 

matophore, making 4 to 7 turns; reproduction by aplanospores, very 

rarely by scalariform conjugation; tubes formed by both gametangia; 

sporangia enlarged or inflated; aplanospores and zygospores ovoid, less 

frequently varying to ellipsoid, 23-29/1. x 50-83/1; median spore wall 

yellowish-brown, smooth. (PI. XXIII, Fig. 4.) 

United States: From Colorado, Wisconsin, and Texas, to Maine and 

North Carolina. 

Widely distributed in Europe; recorded from Siberia, Manchuria, 

China, and Afghanistan. See also S. aplanospora (No. 38), and S. maravillosa 

(No. 65). Only a few zygospores have been seen among the hundreds 

of aplanosporic filaments studied. 

30. Spirogyra i.ongata (Vaucher) Kiitzing 1843. Phycologia 

Generalis, p. 279. Vaucher. Histoire des Conserves, PL 6. 

1803. Includes S. circumscissa Czurda 1932, not S. longata 

(Vaucher) Czurda. 

Vegetative cells 26-38/1 x 45-280/1, with plane end walls; i chro- 

matophore, making 2 to 5 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; zygospores ovoid, varying in some

SPIROGYRA 159 

cells to globose, 28-38/1 x 50-83 /i; median spore wall yellow, smooth. 

(PI. XXIII, Fig. 5.)" 

United States: Common throughout. 

Widely distributed in Europe, reported from East and South Africa, 

Asia, South America, and Australia. In Kentucky (Mclnteer Coll.) this 

species was found hybridizing with S. porticalis. 

The distinctive features of this very common species are the ovoid 

spores and the nearly cylindric sporiferous cells. 

31. Spirogyra oltmannsii Huber-Pestalozzi 1930. "Algen aus 

dem Knysnawalde in Siidafrica." Zeitsch. f. Bot. 23, 

p. 448. 

Vegetative cells 23-27 /u, x 70-125 /x, with plane end walls; i chromatophore, 

zygospores unknown; sporangia cylindric; aplanospores 

ovoid, 22-26/1 X 30-42 /x; median spore wall outwardly [.^] scrobiculate. 

Described from immature specimens. (PI. XXIII, Fig. 6.) 

South Africa. 

32. Spirogyra suecica Transeau 1934. Ohio Jour. Sci. 34, p. 420. 

(îS*. varians var. gracilis) Borge 1923. Arl{. Bot. 6, p. 11, 

PI. I, Fig. 2. 

Vegetative cells 26-29 /x ^ 80-175 /(-, with plane end walls; i chro- 

matophore, making i to 4.5 turns; conjugation scalariform or rarely 

lateral between some cells; tubes formed by both gametangia; fertile 

cells inflated on both sides, usually more on the conjugating side, up to 

60 /J.; zygospores usually ovoid, 32-39/1 x 38-60/1; median spore wall 

yellow, smooth. (PI. XXIII, Fig. 7.) 

United States: Iowa; Ohio; Florida. 

Sweden; France. 

33. Spirogyra gallica Petit 1880. Les Spirogyres des environs de 

Paris, p. 23, PI. 6, Figs. 1-3. 

Vegetative cells 72-75/1 x 1 50-500 /t, with plane end walls; i chro- 

matophore, making 4 to 8 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; fertile cells cylindric; zygospores 

ovoid to ellipsoid, 62-66/1 x 90-110 /t; median spore wall yellow, smooth. 

(PI. XXIII, Fig. 8.) 

France; Belgium; Germany. 

This is the largest of the Spirogyras with i chromatophore; differs from 

S. condensata of about the same dimensions in the ovoid spores and the 

much longer vegetative cells. 

34. Spirogyra lacustris Czurda 1932. Siisswasserflora Mitteleu- 

ropa. 9, p. 176, Fig. 182.

i6o ZYGNEMATACEAE 

Vegetative cells ^8-44/x x 105-160M, with plane end walls; i chromatophorc; 


fertile cells cylindric or very slightly swollen; zygospores ovoid, 42-45 m x 

70-80/1; median spore wall golden-brown, smooth, with suture more 

or less prominent. (PI. XXIII, Fig. 10.) 

Austria. 

Certainly very close to S. porticalis, perhaps merely a clone; apparently 

differs in the brown spores with prominent sutures. 

35. Spirogyra porticalis (Miiller) Cleve 1868. F6rs6f{ till en 

monografi. Nova Acta Reg. Soc. Sci. Upsali. Ser. 3, 

6, p. 22, PI. 5, Figs. 8-9. 

Vegetative cells 40-50 /a x 66-200 m, with plane end walls; i chromatophore, 


by both gametangia; fertile cells cylindric or enlarged; zygospores 

mostly ovoid to globose-ovoid, 38-50 m x 50-83 /x; median spore wall 

yellow, smooth. (PI. XXIII, Fig. 9.) 

United States: Very common in the eastern half. 

Widely distributed on all the continents. Found hybridizing with 5. 

varians at Charleston, Illinois. Hybrid segregates were also present. See 

Amer. Nat., 53, pp. 109-19, 1919. 

36. Spirogyra sahnii Randhawa 1938. Proc. Indian Acad. Sci. 

^> PP- 339-41- 

Vegetative cells 48-^0 /x x 40-74 /a, with plane end walls; i chromatophore, 

making i or 2 turns in the cell; conjugation lateral; tubes 

formed by both gametangia; fertile and sterile cells inflated; zygospores 

ovoid, 22-36 /x X 44-68 /x; median wall [?] 

similar, 20-24 /x ^ 22-36 /x. 

India, Punjab, Dasuya, March, 1931. 

yellow, smooth; aplanospores 

In the original description the median spore wall is described as 

"bluish-green." This appearance is probably due to light refraction and 

colored spore contents. Named for Birbal Sahni of Lucknow University. 

37. Spirogyra lutetiana Petit 1879. Brebissonia. 1, p. 79, PI. 6. 

Vegetative cells 27-40 /x x 70-250 /x, with plane end walls; i chromatophore, 


by both gametangia; fertile cells more or less variable, cylindric, en- 

larged, or slightly inflated; zygospores polymorphic, varying from glo- 

bose to ellipsoid and irregular, 25-44^1 x 35-165 m; median spore wall 

yellow-brown, smooth. (PI. XXIII, Figs. 11-13.) 

United States: Utah; North Dakota; other records very doubtful. 

Widely reported from Europe and Asia; also South Africa. 

Probably none of the species names of Spirogyra has been more frc-

SPIROGYRA i6i 

qucntly misapplied than this one. Looking over the named collections one 

finds 5. lutetiana attached to all sorts of forms in which the cells and spores 

are irregular, although Petit's description and figures are perfectly clear. 

38. Spirogyra aplanospora Randhawa 1938. Proc. Indian Acad. 

Set. 8, pp. 336-37. 

Vegetative cells ix 20-26 x 40-90 /a, uîth plane end walls; i chro- 

matophore, making 3 to 6 turns; fertile and sterile cells irregularly in- 

flated; no conjugation seen; reproduction by aplanospores which are 

ovoid to globose, 24-30 /x 

XXIII, Figs. 17-18.) 

x 30-50 /x; median wall brown, smooth. (PI. 

India, Punjab, Dasuya, lanuary, 1929. 

The dimensions suggest that this is an ecological form of S. mirabilis 

(Hassall) Kutzing. When Spirogyras are growing in water of warm temperatvire 

and low oxygen content they frequently have distorted cells, and 

Randhawa's figures are typical of this condition. 

39. Spirogyra polymorpha Kirchner 1878. Algen. Kryptogame it- 

flora Schlesien, p. 124. 

Vegetative cells 22-30 /x x 45-230 m, with plane end walls; t or 

rarely 2 chromatophores, making i to 10 turns; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells inflated to 26-64 /x; 

zygospores polymorphic, varying from ellipsoid to ovoid and globose, 

22-32 /i. X 25-35 m; median spore wall yellow, smooth. (PI. XXIII, 

Figs. 14-15.) 

Widely reported in Europe. Recently figured and completely described 

by Jao from Szechwan, China. (Sinensia. 6, p. 589, PI. 5, Figs. 56-57. 1935.) 

40. Spirogyra velata Nordstedt 1873. "Beskriftung ofver en 

nyart af Slagtet Spirogyra." Lunds Univ. Arss^rift. 9, p. i, 

PI. I. 

Vegetative cells 29-41 

jj^ x 60-200 /x, with plane end walls; i or rarely 

2 chromatophores, making 2.5 to 6 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells cyUndric or somewhat 

enlarged; zygospores mostly ovoid to cylindric-ovoid, rarely ellipsoid, 

/x 37-57 X 60-100 ;".; outer wall of 2 layers, of which the second is transparent 

and scrobiculate; the median is chitinous, yellow-brown, smooth. 

(PI. XXIV, Fig. I.) 

United States: Iowa; Illinois; Kentucky; Indiana. 

Germany; Russia; South Africa; China. 

The original description of this species gives but i chromatophore. 

Nevertheless, in Nordstedt's collection from Lund (1882) 2 chromatophores 

are present in some of the cells. Petit states that the diameter of the vege- 

tative cells of the specimens collected at Paris ran as high at 54 /x. Possibly 

his collection included another species.

1 62 ZYGNEMATACEAE 

41. Spirogyra occidentalis (Transeau) Czurda 1932. Siisswasser- 

flora Mitteleuropa. 9, p. 183. 

Vegetative cells 40-50^ x 125-300/^, with plane end walls; chromatophores 

i, 2, or 3, making 2 to 6 turns in the cell; conjugation 

scalariform; tubes formed by both gametangia; fertile gametangia 

cylindric or inflated to 66/^; zygospores ovoid to cylindric-ovoid, 

36-56/n X 57-105/^; median spore wall smooth, yellow-brown; outer 

wall of 2 layers, of which the inner is hyaline, scrobiculate. (PI. XXIV, 

Fig. 2.) 

United States: Iowa; Illinois; Indiana; Ohio; Kentucky. 

Canada, British Columbia (Phycoth. Bor.-Amer., No. 961). 

Resembles S. velata but has larger dimensions throughout. 

42. Spirogyra luteospora Czurda 1932. Susswasserflora Mittel- 

europa. 9, p. 181. 

Vegetative cells 22-24 /i ^ 55~90'^» w'wh plane end walls; i chromatophore; 


fertile cells cylindric or enlarged by the spores; zygospores ovoid to 

cylindric-ovoid, 25-26^1 x 38-46/Li; median spore wall golden-brown, 

scrobiculate; pits about 2/^ in diameter. (PI. XXIV, Fig. 3.) 

Bohemia. 

43. Spirogyra sulcata Blum 1943. Amer. Jour. Bot. 30, p. 783, 

Figs. 9-11. 

Vegetative cells ^7-46 m x 50-160 ju,, with plane end walls; i(-2) 

chromatophores, with prominent median furrow, making 2 to 5 turns 

in the cells; conjugation scalariform; tubes formed by both gametangia; 

fertile cells inflated on the outer side; zygospores ovoid, 43-46111 x 52- 

62 fj.; median spore wall thick, brown, and reticulate. (PI. XXIV, Fig. 4.) 

United States: Wisconsin, Madison. 

44. Spirogyra westii Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 224. S. porticalis var. ajricana G. S. West 1907. 

]our. Linn. Soc. of London Bot. 38, p. 105. 

Vegetative cells 40-41 /i x 60-160/'., with plane end walls; i chromatophore, 


tubes formed by both gametangia; fertile cells enlarged; zygospores 

ovoid, about 58 /x x /a; 

93 median spore wall finely wrinkled, or corrugate. 

Africa, Tanganyika. 

45. Spirogyra obovata Jao 1935. Sinensia. 6, p. 596, PI. 7, Fig. 73. 

Vegetative cells 25-29/A x 70-182/1, with plane end walls; i chromatophore 

(rarely 2), making 2.5-6 turns in the cell; conjugation

SPIROGYRA 163 

scalariform; tubes formed by both cells; reproduction by zygospores 

and aplanospores; zygospores ovoid, 29-35 /u ^ 44~73'"'l aplanospores 

ovoid, /i. 29-32 X 38-42 /x; median wall punctate, yellow at maturity. 

(PI. XXIV, Fig. 5.) 

China, Szechwan, November 15, 1933. 

46. Spirogyra asiatica Czurda 193 1. Susswasserflora Mitteleu- 

ropa. 9, p. 185. 1932. 

Vegetative cells 46-51 /x x ioo-i6o;u,, with plane end walls; i chromatophore 

(rarely 2); conjugation lateral; tubes formed by both cells; 

fertile cells enlarged; zygospores ovoid, 60-65 ju. x 80-120 /a; median spore 

wall dark brown, and minutely granulose; suture more or less prom- 

inent. (PI. XXIV, Fig. 6.) 

Central Tibet, altitude 17,000 feet. 

47. Spirogyra lagerheimii Wittrock 1889. In Wittrock and Nord- 

stedt Algae Exsiccatae, Nos. 961 and 962. Bot. Notiser 

1889. p. 165. 

Vegetative cells 25-33^1 x 75-1 50 m, with plane end walls; i chro- 

matophore, usually narrow, making .5 to 4 turns; conjugation scalariform 

and lateral; tubes formed by both cells; fertile cells cylindric or 

enlarged; zygospores ellipsoid with more or less pointed ends, 25-38 /a x 

50-100 /a; median spore wall yellowish-brown, finely punctate. (PI. 

XXIV, Fig. 7.) 

United States: Illinois; Ohio; Massachusetts; New Hampshire. 

Sweden; Germany; Latvia; Finland. 

In the many collections seen, the chromatophores were uniformly narrow 

and formed open spirals. 

48. Spirogyra taftiana Transeau 1944. Ohio Jour. Sci. 44, p. 243. 

Vegetative cells 18-25 /a ^ 50-96 ;", with plane end walls; i chromatophore, 

making 2-4 turns in the cell; conjugation scalariform; tubes 

formed by both gametangia; receptive gametangia enlarged or fusi- 

form-inflated; sterile cells often bulliform; zygospores ellipsoid, 24-34 /a 

x 42-80,11; median wall distinctly and densely punctate; pits more or 

less angular, yellow. (PI. XXIV, Fig. 8.) 

United States: Texas, Huntsville (Taft Coll.). 

Named for C. E. Taft, The Ohio State University, author of many 

papers on fresh-water algae. 

49. Spirogyra perforans Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 228, PI. 21, Fig. 57. 

Vegetative cells 14-18 ft x 72-120^1, with plane end walls; i chromatophore, 

making 3 to 6 turns; conjugation scalariform; tubes formed

164 

ZYGNEMATACEAE 

by both gametangia; fertile cells enlarged; zygospores ellipsoid, 25-29;/. 

X (50-) 65-69 m; median spore wall yellow-brown, coarsely punctate. 



50. Spirogyra porangabae Transeau 1938. Amer. Jour. Bot. 25, 

p. 525. 

Vegetative cells 11-15M x 65-145^1, with plane end walls; i chro- 

matophorc, making 4 to 9 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; receptive gametangium enlarged or 

slightly inflated; sterile cells inflated, often buUiform; zygospores ellip- 

soid, 2 1-27 /J. X 47-54 i^; median wall at first smooth, at maturity irreg- 

ularly but distinctly punctate, yellow-brown. (PI. XXIV, Fig. 11.) 

Brazil, Ceara, Porangaba, October 8, 1935 (Drouet Coll.). 

This species resembles 5. bullata Jao, but is smaller and the spore wall 

is punctate. 

51. Spirogyra minutifossa Jao 1935. Trans. Amer. Micros. Soc. 

54, pp. 3-4, PL I, Fig. 5. 

Vegetative cells 16-19;", ^ 55-176^, with plane end walls; i chromatophore, 

making 2-6.5 turns; conjugation scalariform; tubes formed 

by both gametangia; fertile cells fusiform-inflated; zygospores ellipsoid 

with rather pointed ends, 22-26 /i- x 35-48 /a; median spore wall irreg- 

ularly and minutely grooved, yellow at maturity. (PI. XXIV, Fig. 10.) 

United States: Massachusetts, Nonamesset Island, July 14, 1933. 

Nova Scotia (Hughes Coll.). 

52. Spirogyra skujae Randhawa 1938. Proc. Indian Acad. Sci. 

8 (4), Sec. B, p. 338. 

Vegetative cells 14-17/J. x 84-140M, with plane end walls; i chromatophore, 

making 3-5 turns; conjugation scalariform; tubes formed 

by both gametangia; fertile cells inflated medially to 26-34 /x; zygospores 

ellipsoid, 24-30 /x X 40-52 m; median spore wall reticulate, yellow-brown. 


India, Fyzabad, Upper Punjab, February 7, 1937. 

Resembles S. hoehnei Borge in the form of the fertile cells, but has 

smaller dimensions throughout and the median spore wall is reticulate, not 

punctate. This description includes S. reticuleana. 

53. Spirogyra hoehnei Borge 1925. Arl{. Bot. 19, p. 13, PI. 2, 

Fig. I. 

Vegetative cells 26-29/A x i50-350iu., with plane end walls; i chromatophore, 


by both cells; fertile cells inflated toward the middle to 52 /a; zygospores

SPIROGYRA 165 

ellipsoid, ^P-^î^ x 50-65 ft; median spore wall yellow, irregularly and 

coarsely punctate. (PI. XXIV, Fig. 13.) 

United States: Kentucky (Mclnteer Coll.). 

South America, Paraguay; South Africa. 

54. Spirogyra robusta (Nygaard) Czurda 1932. Trans. Roy. Soc. 

S. Africa. 20, Pt. II. Siisswasserfiora Mitteleuropa. 9, 

p. 187. 

Vegetative cells 29-35 /a i^ diameter, with plane end walls; i chromatophore; 

conjugation scalariform; tubes formed by both cells; fertile 

cells inflated, 43-65 a*, in diameter; zygospores ellipsoid, 32-60 /x x 

54-104 /i; median spore wall yellowish-brown, with faint, irregular 

scrobiculations. (PI. XXIV, Figs. 14-15.) 

South Africa. 

55. Spirogyra subpapulata Jao 1935. Sinensia. 6, p. 597, PL 7, 

Figs. 74-75. 

Vegetative cells 22-26 ^ x 41-166 /x, with plane end walls; i chromatophore, 

making 2-7 turns in the cell; reproduction by either zygo- 

spores or aplanospores; conjugation scalariform; tubes formed by both 

cells; sterile cells usually swollen to 58 yn in diameter; zygospores ellip- 

soid, with pointed ends, 21-29 ja x 41-60^1; aplanospores subglobose or 

ellipsoid, 22-26 /^ x 32-48 /x; median wall finely and densely punctate, 

yellow at maturity. (PI. XXV, Figs. 1-2.) 

China, Szechwan, December, 1933, and January, 1934 (Jao Coll.). 

This species resembles Spirogyra papulata Jao, but has smaller vege- 

tative cells and punctate spores. 

56. Spirogyra papulata Jao 1935. Sinensia. 6, p. 598, PL 7, Figs, 

76-78. 

Vegetative cells 28-32 /x x 64-176)0,, with plane end walls; chromatophore 

single, containing large pyrenoids; conjugation scalariform; 

tubes formed by both gametangia; fertile cells usually shortened and 

inflated on the conjugating side, up to 55 /x in diameter; sterile cells 

sometimes swollen to 64^^; zygospores ellipsoid, very rarely subglobose, 

22-32 /x x 35-55 ^t; median spore wall irregularly reticulate, golden yellow 

at maturity. (PI. XXV, Figs. 3-5.) 

China, Szechwan, January, 1933. 

57. Spirogyra scrobiculata (Stockmayer) Czurda 1932. Siiss- 

wasserfiora Mitteleuropa. 9, p. 182. 

Vegetative cells 30-40 /a x 30-90 /a, with plane end wails; i chromatophore; 


fertile cells inflated on the conjugating side; zygospores ellipsoid.


34-38^1 X 58-68 /x; median spore wall yellow to yellow-brown; scrobic- 

ulate. (PI. XXIV, Fig. 17; PI. XXV, Figs. &-y.) 

United States: Utah; Wisconsin; Illinois; Kentucky; Michigan; Ohio; 

Mississippi. 

Austria. 

Differs from S. varians in the scrobiculate median spore wall. 

58. Spirogyra aphanosculpta Skuja 1937. Hedwigia. 77, p. 55. 

Vegetative cells 32-38/a x 50-119/1, with plane end walls; i chromatophore, 


by both gameiangia; female gametangia 43-150/1 in length, cylindric 

or inflated on the conjugating side; sterile cells sometimes inflated; 

zygospores ellipsoid to cylindric-ellipsoid, 31-40/1 x 43-81 /t; median 

spore wall yellow-brown, punctate with angular and irregular pits. 

(PI. XXV, Fig. 8.) 

United States: New Hampshire, Hanover (Blum Coll.). 

Greece, Taygetus; Africa, Cape Colony (Stephens Coll.). 

59. Spirogyra kaffirita Transeau 1934. Tm?2s. Amer. Micros. 

Soc. 53, p. 228, Fig. 59. 

Vegetative cells 39-45/1 x 65-140/1, with plane end walls; i chromatophore; 


fertile cells inflated on the inner side; zygospores ellipsoid, 32-40,1 x 

45-6o(-75) p-'y median spore wall yellow, shallow-granulate, reticulate. 

(PI. XXV, Fig. II.) 

Africa, Cape Colony (Stephens Coll.). 

60. Spirogyra tuberculata Lagerheim 1896. Wittrock and Nord- 


Vegetative cells 35-37 /^ x 70-165/1, with plane end walls; i chromatophore; 


fertile cells inflated on both sides; zygospores ellipsoid with rounded 

ends, 30-38/1 x 50-67 /j.; median spore wall yellow, irregularly verrucose. 

Sweden, Uppsala. 

The inflation of the fertile cells and the smaller dimensions distinguish 

this species from S. australensis. 

61. Spirogyra daedalea Lagerheim 1888. Nuova Notarisia, p. 592. 

Vegetative cells 33-36/1 x 180-330/1, with plane end walls; i chro- 

matophore, making 2 to 3.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric or enlarged to 36-45/1, 

and shortened; zygospores ellipsoid, 30-40/1 x 50-96/1; median spore 

wall yellow-brown, very irregularly corrugate. (PI. XXV, Figs. 9-10.) 

United States: Iowa.

Germany; Latvia; Yugoslavia; Finland; India, 

SPIROGYRA 167 

In the original collection there is a deposit of brown granules between 

the outer and median walls. 

62. Spirogyra daedaleoides Czurda 1932. Siisswasserflora Mittel- 

europa. 9, pp. 180-81. Skuja. Acta Horti Bot. Univ. Lat- 

viensis. 4, p. 39. 1929. 

Vegetative cells 30-44 ju x 65-240 /a, with plane end walls; i chromatophore, 

making 2 to 8 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells enlarged or slightly 

inflated (-50 /x); zygospores ellipsoid, 30-46 /x x 46-90 ju; median spore 

wall brown, with prominent irregular reticulate ridges. (PI. XXV, 

Figs. 13-15.) 

United States: Wisconsin (Prescott Coll.); Illinois; Ohio. 

Latvia, Saaremaa. 

63. Spirogyra australensis Mobius 1895. In Bailey, Queensland 

Flora. Dept. of Agric. Bot. Bull. 1, p. 34, PI. 9, Fig. i. 

Vegetative cells about 50 m x T00-150M, with plane end walls; i 

chromatophore, making 2.5 to 3 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric or enlarged; zygo- 

spores elhpsoid, 40-45^1 X 74^7 i^; median spore wall yellowish-brown, 

finely verrucose. (PI. XLI, Fig. 12.) 

Australia, Queensland. 

Distinguished from S. tuberculata Lagerheim by the larger dimensions 

throughout and by the cylindric or enlarged fertile cells; from S. daedalea 

Lagerheim by the verrucose median spore wall. 

64. Spirogyra labyrinthica Transeau 1934. Ohio Jour. Sci. 34, 

p. 420. {S. daedalea var. major Him 1913) in Borge, 

Zygnemales. Siisswasserflora Deutschland. 9, p. 27. 

Vegetative cells 50-63 /x x 150-400 m, with plane end walls; i chromatophore; 


fertile cells cylindric or enlarged; zygospores ellipsoid, ju. 43-58 x 

80-118 /x; median spore wall brown, distinctly reticulate. 

Germany, Wiirzburg. 

SPECIES WITH PLANE END WALLS 

TWO OR MORE CHROMATOPHORES 

65. Spirogyra maravillosa Transeau 1938. Amer. ]our. Bot. 25, 

p. 525. 

Vegetative cells 2^-2gix x 108-260 /x, with plane end walls; 2 or 3 

chromatophores, making 2 to 5 turns in the cell; conjugation unknown;


aplanospores broadly ellipsoid, 28-36/i. x 43-6o(-72) /x; median wall 

smooth, vellow-brovvn ; sporangia enlarged or slightly inflated. (PI. 

XXVI, Figs. 1-2.) 

Brazil, Belem, July 9, 1935 (Drouet Coll.). 

This species resembles Number 29, S. mirabilis (Hassall) Kutzing but 

differs in having 2 or 3 chromatophores. 

66. Spirogyra irregularis Nageli 1849. In Kiitzing, Species Algarum, 

p. 440; also 1855, Tab. Phycoth., 5, PI. 23, Fig. 2. 

Vegetative cells 32-37 y^ x 65-250 /x, with plane end walls; 2 to 4 

chromatophores, making .5 to i turn; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; zygospores ellipsoid 

to cylindric-ellipsoid, 30-36 ju. x 45-90^11; median spore wall yellowishbrown, 

smooth. (PI. XXVI, Fig. 3.) 

United States: Illinois; Missouri (Drouet Coll.). 

Widely reported from western and central Europe. 

67. Spirogyra fuellebornei Schmidle 1902. Englcr's Bot. ]ahrb. 

32, p. 76, PI. 3, Fig. 2. 

Vegetative cells 40-42 /x x 120-240 m, with plane end walls; 3 chro- 

matophores, making i to 2 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells cyhndric; zygospores 

ellipsoid, more or less pointed, 32-44 /x x 50-80 ju.; median spore wall 

smooth, yellow-brown. (PI. XXVI, Fig. 4.) 


Africa; Nyassa Lake region; Central America, Panama. 

68. Spirogyra microspora Jao 1935. Sinensia. 6, pp. 593-94, PI. 6, 

Fig. 65. 

Vegetative cells 35-38 /^ x 64-131 m, with plane end walls; 2 chro- 

matophores, broad with large pyrenoids, making 1.5-3.5 turns in the 

cell; conjugation lateral; tubes formed by both gametangia; fertile cells 

cylindric; zygospores ellipsoid, 29-32^ x 51-61 /x; median wall smooth, 

yellow at maturity. (PI. XXVI, Fig. 5.) 

China, Szechwan, November, 1933. 

69. Spirogyra hollandiae Taft 1947. Ohio Jour. Sci. 47, p. 173. 

Vegetative cells 36-41 /a x 60-192/i., with plane end walls; 2 chro- 

matophores, broad with large pyrenoids, making 1.5-2.5 turns in the 

cell; conjugation usually lateral; tubes formed by both gametangia; 

sterile cells sometimes inflated; receptive gametangia cylindric or en- 

larged; zygospores ellipsoid with rounded ends, 38-42/1 x 62-78 /x; 

median wall smooth, bright yellow at maturity. (PI. XXVI, Figs. 6-7.)

Coll.). 

SPIROGYRA 169 

Dutch New Guinea, Hollandia (Robert Sigafoos Coll.), Biak (Britton 

In the Biak collection several instances of scalariform conjugation were 

found. See also Number 72. 

70. Spirogyra submarina (Collins) Transeau 1915. Ohio Jour. 

Sci. 16, p, 25. Collins. 1909. Green Algae of North America, 

p. no. 

Vegetative cells 21-32 a*- x 6'^-iy'îJi, with plane end walls; 2 to 3 

chromatophores, making 1.5 to 3 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells enlarged; zygospores ellipsoid, 

/tt 31-37 X 56-120 /a; median spore wall yellowish-brown, smooth. 

United States: Massachusetts; Connecticut. 

Bermuda; China, Peiping and Nanking (Li Coll.). 

71. Spirogyra rivularis (Hassall) Rabenhorst 1868. Flora Europaea 

Algarum. 3, p. 243. 

Vegetative cells 36-41 ;«. x 100-400 /x, with plane end walls; 2 to 3 

chromatophores, making 2.5 to 3.5 turns in the cells; conjugation scalar- 

iform, rare; tubes formed by both gametangia; fertile cells shortened, 

cylindric or enlarged; zygospores ellipsoid, 35-42 a^ x 60-100 /x; median 

spore wall yellow or brownish-yellow, smooth. (PI. XXVI, Fig. 8.) 

United States: Kansas; Iowa; Michigan; Alabama; Kentucky. 

Widely distributed in Europe, South Africa, New Guinea, and several 

provinces of China. 

Most of the early records of this species are based on vegetative material. 

It is said to occur in running water, attached to submerged objects. In the 

vegetative condition it certainly cannot be distinguished from S. decimina, 

which in America is also frequently attached and floating in small streams. 

See note under S. turfosa (No. 79). 

72. Spirogyra biformis Jao 1935. Sinensia. 6, pp. 594-95, PI. 6, 

Fig. 66. 

Vegetative cells 38-48/t x 64-i5o(-i9o) /i, with plane end walls; 

chromatophores (i-)2-3, making 1.5 to 4.5 turns; conjugation usually 

lateral, rarely scalariform; tubes formed by both gametangia; fertile 

cells cylindric or slightly enlarged, sometimes shortened to 38 /x; sterile 

cells some times swollen to 58 /x in diameter; zygospores ellipsoid with 

rounded ends, 36-51 û. x 60-83^",; median spore wall yellow, smooth. 

(PI. XXVI, Figs. 9-10.) 

China, Szechwan; New Guinea (Robert Sigafoos Coll.); Philippines, 

Leyte (Britton Coll.); Brazil (Drouet Coll.). Compare with Number 69. 

In the collection from Leyte conjugation is scalariform, elsewhere lat- 

eral. In one of the collections from Leyte a few cells have 4 chromatophores.


73. Spirogyra hyalina Cleve 1868. Nova Acta Reg. Soc. Sci. 

Upsali. Ser. 3, 6, p. 17, PI. 3, Figs. 1-6. 

Vegetative cells 45-60 /a x 80-240 yî, with plane end walls; chro- 

matophores, 2, 3, or 4, making ,5 to 3 turns; conjugation lateral or 

scalariform; tubes formed by both gametangia; fertile cells cylindric, 

or slightly inflated; zygospores ellipsoid, more or less pointed, 45-60/^ x 

60-130 m; median spore wall brown, smooth; aplanospores similar, 

somewhat smaller. (PI. XXVI, Figs. 11-12.) 

United States: Iowa; Mississippi. 

Sweden; Puerto Rico; India; China. 

Cleve's figures show the characteristic long conjugating tubes. In lateral 

conjugation the form of the tube is almost unique. 

74. Spirogyra pseudoneglecta Czurda 1932. Siisswasserfiora Mit- 

teleuropa. 9, p. 194. 

Vegetative cells 55-60^1 x 130-240 m, with plane end walls; 3 chromatophores; 

conjugation lateral and scalariform; tubes formed by both 

gametangia; fertile cells cylindric or slightly swollen; zygospores ellip- 

soid, 50-52 /A X 95-100 /x; median spore wall reddish-brown, smooth. 

(PL XXVI, Figs. 13-14.) 

Moravia. 

75. Spirogyra columbiana Czurda 1932. Siisswasserfiora Mitteleuropa. 

9, p. 190. 

Vegetative cells 48-54 /a x 90-1 80 ju, with plane end walls; chromatophores 

(i-)3; conjugation scalariform; tubes formed by both gametangia; 

fertile and sterile cells cylindric; zygospores ellipsoid, about 

50 /i X 70 /x; median spore wall smooth, yellow-brown, suture distinct. 

(PI. XXVI, Fig. 15.) 

South America, Colombia; South Africa; lava. 

76. Spirogyra angolensis Welwitsch 1897. Jour. Bot. 35, p. 41. 

Vegetative cells 49-62 jn x 60-200 i^, with plane end walls; 2 or 3 

chromatophores, making 2 to 3 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric or enlarged; zygospores 

ellipsoid with somewhat pointed ends, 52-57 m x 84-100 m; median 

spore wall smooth, yellow. 

United States: Iowa (Tiffany Coll.). 

South Africa, Angola; China, Yunnan. 

77. Spirogyra welwitschii W. & G. S. West 1897. ]our. Bot. 35, 

p. 41. 

Vegetative cells 65-75/ii x 40-150^1, with plane end walls; 2 (rarely 

3) chromatophores, making i to 2 turns; conjugation scalariform; tubes

SPIROGYRA 171 

formed by both gametangia; fertile cells cylindrlc; zygospores broadly 

ellipsoid, 57-58 /x x 69-71 /x; median spore wall smooth. 

South Africa, Angola, July, 1854. 

78. Spirogyra parvispora Wood 1869. Proc. Amer. Phil. Soc. H, 

p. 139. 1872. Smithson. Contribu. Knowledge. 19, p. 169, 

PI. 15, Fig. 7. 

Vegetative cells about y^p- x 150-300 ft, with plane end walls; 4 

chromatophores, making 1.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells not inflated; spores ellipsoid, 

ft 50 X 75-100 /(a; median spore wall brown, smooth. (PL XXVI, Fig. 16.) 

United States: Florida. 

79. Spirogyra turfosa Gay 1884. Essai Monogr. Conjug., p. 187, 

PI. 4, Fig. 3. 

Vegetative cells 68-78^1 x 68-350^4, with plane end walls; 3-4 chro- 

matophores, making 1.5 to 4 turns; fertile cells cylindric; conjugation 

scalariform; tubes formed by both gametangia; zygospores ellipsoid, 

pointed, 65-78/11, x 120-140^4; median spore wall smooth, yellow. (PI. 

XXVI, Fig. 17.) 

United States: Kansas; Mississippi; Alabama. 

Galicia. 

In the 3 collections from the United States this species was associated 

with 5. rivularis, which it resembles in all characteristics except size. It 

would be interesting to know the relative chromosome complements of these 

2 species. It might be a mutation from S. rivularis due to a single gene 

change. 

80. Spirogyra nitida (Dillwyn) Link 1833. Handbttch, Pt. 3, 

p. 262. 

Vegetative cells 70-80 ft x 90-300 ft, with plane end walls; 3-5 chromatophores, 

making .5 to 1.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cyUndric or enlarged; zygospores 

eUipsoid, rarely somewhat ovoid, 60-76 ft x 90-177 ft; median 

spore wall brown, smooth. (PI. XXVII, Figs. 1-2.) 

United States: Many records from Iowa and Wisconsin to Massachu- 

setts, south to Mississippi and Florida. 

Europe; India; Australia; China; South Africa. 

This species consists of many overlapping forms that differ only slightly 

in dimensions, hence the spread in cell diameters. Near Starkville, Mississippi, 

I found this species hybridizing with S. crassa. In the undrained pond 

there were also the resulting hybrid segregates. 

81. Spirogyra hymerae Britton & Smith 1942. Ohio Jour. Sci. 

42, p. 70.

172 

ZYGNEMATACEAE 

Vegetative cells 83-92 /x x 43-256 m, with plane end walls; 2-4 chro- 

matophores, usually 3, making .5-2 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; receptive gametangia cylin- 

dric or slightly enlarged; zygospores mostly ellipsoid, 5^-79/^ x 83-128 /x; 

all walls smooth; median wall yellow. (PI. XXVII, Fig. 3,) 

United States: Indiana, Sullivan County, September 10, 1936. 

Resembles S. setijormis but differs in chromatophore complement and 

in the proportionately smaller spores. 

82. Spirogyra setiformis (Roth) Kiitzing 1845. Phycologia Ger- 

manica, p. 223. 

Vegetative cells 90-1 15 j". x 100-225 /i, ^^'^'^^ plane end walls; chromatophores 

4, making .5 to 4 turns in the cells; conjugation scalar iform; 

tubes formed by both gametangia; receptive gametangia cylindric; 

zygospores ellipsoid, 85-1 00 ^ x 11 5-1 60 /x; median wall brown and 

smooth. (PI. XXVII, Figs. 4-5.) 

United States: Iowa; Illinois; Indiana; Pennsylvania; New Jersey; 

Massachusetts. 

Widely reported from European countries. 

This is certainly not the species described by Czurda (1932) which has 

6 to 10 chroma tophores. The earliest figures published agree with those of 

Petit (1880) in having 4 chromatophores. In any event, the description 

given here characterizes a species that is very common in the east central 

states and agrees with Borge's interpretation in the first edition of the 

SiisswasserfJora, 9. In the Handbuch der Pflanzenanatomie (Bd. VI, 2 Teil., 

p. 65) Czurda (1937) figures this species with 4 chromatophores. 

83. Spirogyra elliptica Jao 1935. Smensia. 6, p. 596, PI. 6, Fig. 72. 

Vegetative cells 115-128^^ x 128-568 /a, with plane end walls; 4 to 6 

chromatophores, making i to 3 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; fertile cells cylindric and 

shortened; zygospores ellipsoid with pointed ends, 82-106 /a x 144-202 /x; 

median wall smooth, yellow-brown. (PI. XXVII, Fig. 6.) 

China, Szechwan, January, 1933. 

84. Spirogyra wollnyi de Toni 1889. Sylloge Algarum. 2, p. 754. 

Wollny. Hedwigia. 1887, p. 166 (as S. elegans). 

Vegetative cells 90-100^^ x 270-350 /a, with plane end walls; 6 to 8 

chromatophores, making 2 to 2.5 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells cylindric; zygo- 

spores elhpsoid, 90-100/U, X 140-190/A; median wall yellow-brown, 

smooth, with distinct suture. 

CJcrmany, Dresden; South Africa, Queenstown Cape, July, 1930 

(Stephens Coll.).

SPIROGYRA 173 

This imperfectly described species of Wollny has been completed by 

the additional data gleaned from Miss Stephens' collection. 

85. Spirogyra wrightiana Transeau 1938. Amer. ]our. Bot. 25, 

p. 527, Figs. 16-17. 

Vegetative cells 130-165/u, x 275-43o(-69o) î, with plane end walls; 

6-8 chromatophores, making 1-3 turns in the cell; conjugation unknown; 

aplanospores mostly ellipsoid, 100-126 /j. x 158-206 /a; sporangia 

cyhndric and of the same dimensions as the vegetative cells; spore walls 

in the material seen probably not mature, smooth and colorless. (PI. 

I, Figs. 4-5; PI. XXVII, Figs. 7-8.) 

South America, Brazil, Parahiba, July 14, 1934 (Drouet Coll.). 

Very similar in appearance to the preceding species; and, as is usual in 

aplanosporic species, the spores are small compared with the volume of the 

vegetative cells in which they form. 

86. Spirogyra yunnanensis Li 1939. Bull. Fan Mem. Inst. Biol., 

Botany. 9, p. 224, PL 27, Fig. 2. 

Vegetative cells 98-1 10 /u. x 224-268 /x, with plane end walls; chromatophores 

6-8, making 2-4 turns in the cell; conjugation scalar iform; 

tubes formed by both gametangia; fertile cells cylindric and shortened; 

zygospores ellipsoid, 88-96 /^ x 120-180^; median spore wall smooth, 

yellow. (PI. XXVII, Fig. 9.) 

China, Yiinnan. 

87. Spirogyra hatillensis Transeau 1936. Brittonia. 2, p. 171. 

Vegetative cells 120-130111 x 108-450/4, with plane end walls; 6 to 8 

chromatophores, having .5 to 4 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; sterile cells more or 

less swollen; zygospores ellipsoid, 85-125/1 x 130-160/1; median spore 

wall brown, smooth. Spores small compared with volume of gam- 

etangium. (PI. XXVII, Fig. 10.) 

United States: North Carolina (Whitford Coll.). 

Puerto Rico, Hatillo, February, 191 5 (Wille Coll.). 

88. Spirogyra ellipsospora Transeau 1914. Amer. Jour. Bot. 1, 

p. 294. 

Vegetative cells 125-150/1 x 125-500 /t, with plane end walls; 3 to 8 

chromatophores, making .4 to 5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; zygospores ellipsoid, 

more or less pointed, 100-140 /x x 160-255/1; median spore wall smooth, 

yellow-brown. (PI. XXVII, Fig. 11.) 

Generally distributed in the eastern half of the United States, but no 

reports from the southern coastal plain. 

Central China.

174 

ZYGNEMATACEAE 

89. Spirocyra splendida G. S. West 1914. Mem. Soc. Neucha- 

teloise Sci. Nat. 5, pp. 10 13-51. 

Vegetative cells 158-166/1 x 210-330 m, with plane end walls; 5 to 6 

chromatophores, making i.t, ro 2 turns in the cells; conjugation 

scalariform; tubes formed by both gametangia; fertile cells cylindric; 

zygospores ellipsoid, about 1^5^^ x 216/u.; median spore wall yellow, 

smooth. (PI. XXVII, Fig. 17.) 

South America, Colombia, Cundinamarca. 

90. Spirogyra emilianensis Bonhomme 1858. Sur quelques algues 

d'eau douce, p. 7, PI. 2, Fig. 2. 

Vegetative cells 50-60 /x x 100-200 /m, with plane end walls; 4 to 5 

chromatophores, making .2 to 2.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; zygospores ovoid, 

52-60/U. X 90-124/i; median spore wall brown, smooth. (PI. XXVII, 

Fig. 12.) 

United States: Massachusetts, Boston (Bullard Coll.). 

France. 

91. Spirogyra exilis W. & G. S. West 1907. Ann. Roy. Bot. Gard., 

Calcutta. 6, p. 186. 

Vegetative cells 27-30^1 x 42-120 /x, with plane end walls; 2 broad 


formed by both gametangia; fertile cells enlarged on the inner face, or 

cylindrical; sterile cells often greatly inflated to 49 m; zygospores ovoid 

to oblong, 27-30 ju. 

XXVII, Fig. 13.) 

X 36-45^1; median spore wall yellow, smooth. (PI. 

Burma. 

92. Spirogyra distenta Transeau 1934. Ohio Jour. Sci. 34, p. 420. 

Fritsch. Trans. Roy. Soc. S. Africa. 9, p. 46, as S. decimina 

var. infiata. 

Vegetative cells 48-52 /x x 8i-i8o/i, with plane end walls; 2 chro- 

matophores, making 1.5 to 2 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric or enlarged; sterile 

cells inflated to 75/x; zygospores ovoid, 49-55/^ x 50-1 00 /t; median spore 

wall yellow, smooth. 

United States: Illinois; Kentucky; Ohio. 

South Africa. 

93. Spirogyra triplicata (Collins) Transeau 1944. Ohio Jour. 

Sci. 44, p. 243. Collins, F. S. S. decimina var. triplicata. 

Phycoth. Bor.-Amer., No. 960. Green Algae of North 

America, p. no. 1912.

SPIROGYRA 175 

Vegetative cells 35-45 M x 140-200 /j-, with plane end walls; 3 chro- 

matophores, making 1.5 to 3 turns; conjugation scalariform; tubes 


34-48 A^ X ;t(,; 48-54 median spore wall yellow, smooth. 

United States: California; Illinois; Kentucky; Massachusetts. 

94. Spirogyra siamensis nom. nov. Bot. Tidsskrijt. 24, p. 161, as 

S. decimina var. tropica W. & G. S. West. Transeau 1944. 

Ohio Jour. Sci. 44, p. 243 as S. tropica, a name preoccupied 

by Kiitzing. 

Vegetative cells 46-50 /x x 100-250 /«. with plane end walls; 3 chro- 

matophores, making 2.5 to 4.6 turns; conjugation scalariform; tubes 


46-50 ju. X 81-124 m; median spore wall yellow, smooth. 

Siam, Island of Koh Chang. 

95. Spirogyra neglecta (Hassall) Riitzing 1849. Species Al- 

garurn, p. 441. 

Vegetative cells 55-67 /^ x 1 00-300 /x, with plane end walls; 3 chro- 

matophores, making i to 2.5 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells enlarged, or often greatly 

enlarged or inflated, and spores may develop at right angles to the filament; 

zygospores and aplanospores ovoid, ju, 54-64 x 75-100 /x; median 

spore wall yellow, smooth. (PL XXVII, Figs. 14-15.) 

chusetts. 

United States: Colorado; Illinois; Indiana; Ohio; Kentucky; Massa- 

Germany; Finland; Czechoslovakia; Macedonia; Java; Siam; South 

Africa; China; India; West Indies. 

The species described by Ripart (1876) as S. ternata frequently has 

been found associated with this species, and not infrequently at opposite 

ends of the same filaments. The short crowded cells of "ternata" are the 

result of more rapid cell division just preceding conjugation. 

96. Spirogyra decimina (Miiller) Kiitzing 1843. Phycologia Gen- 

eralis, p. 279. Wittrock and Nordstedt Algae Exsiccatae, 

No. 1372. 

Vegetative cells 32-42 /a x 66-1 50 /x, with plane end walls; 2-3 chromatophores, 

making i to 2 turns; conjugation scalariform; tubes 


spores ovoid to globose, 31-40/4 x 31-68 />(.; median spore wall yellow, 

smooth. (PL XXVII, Fig. 16.) 

United States: Common in most states from Colorado eastward. 

Europe; Asia; Africa; West Indies; Java; South America. 

Under this name Czurda (1932) has described a species with ellipsoid

176 

ZYGNEMATACEAE 

spores and 1-2 chromatophorcs. This description obviously disregards all 

previous descriptions and exsiccatae. 

97. Spirogyra plena (W. & G. S. West) Czurda 1932. Siisswasser- 

flora Mittelewopa. 9, p. 193, Ann. Roy. Bot. Gard., Cal- 

cutta. 6, p. 187. 1907. 

Vegetative cells 38-44 m x 57-88 m, with plane end walls; 2 or 3 chromatophores; 

conjugation scalariform and lateral; tubes large and 

formed by both gametangia; fertile cells cylindric or enlarged on the 

conjugating side; zygospores ovoid, 40-44^1 x 64-73 (-88) /n; median 

spore wall yellow, smooth. (PI. XXVIII, Figs. 1-2.) 

United States: Iowa; Indiana; Kentucky; Ohio. 

Asia, Burma; China, Yunnan; India, Bombay. 

98. Spirogyra szechwanensis Jao 1935. Smensia. 6, p. 595, PI. 6, 

Fig. 69. Amer. ]our. Bot. 23, p. 55. 1936. 

Vegetative cells 75-90 /^ x 125-240 At, with plane end walls; 4 chro- 

matophorcs, rarely 2 or 3, making 1-2 turns in the cell; conjugation 

scalariform; tubes formed by both gametangia; fertile cells cylindric; 

zygospores ellipsoid to ovoid, 57-68 m x 100-210 m; median spore wall 

smooth, yellow at maturity. (PI, XXVIII, Fig. 3.) 

China, Chungking. 

99. Spirogyra jugalis (F1. Dan.) Kiitzing 1845. Phycologia Germanica, 

p. 223. 

Vegetative cells 75-103 m x 80-300 /x, with plane end walls; 3 to 4 

chromatophorcs, making i to 2 turns; conjugation scalariform; tubes 


spores ovoid, 87-108 /i. x 120-155 /x; median spore wall brown, smooth. 

(PI. XXVIII, Fig. 4.) 

United States: Minnesota; Iowa; Illinois; Michigan; Massachusetts. 

Europe; China. 

100. Spirogyra margaritata Wollny 1877. Hedivigia. 16, p. 164. 

Vegetative cells ioo-120/x x i50-400iu, with plane end walls; 13 to 

15 chromatophorcs, making .25 to .5 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells cylindric or inflated to 

165)".; zygospores ovoid, 92-125/^ x 140-200/1; median spore wall smooth, 

brown. (PI. XXVIII, Fig. 5.) 

Germany, Dresden. 

Thirty years ago Dr. Nordstedt sent me dried material of this species 

collected by R. Wollny in 1877, which I assume to be a part of the type 

collection. Most of the spores are immature, but are globose only when seen 

along the long axis. The above details are based on this collection and 

complete the description.

SPIROGYRA 177 

loi. Spirogyra polytaeniata Strasburger 1888. Ueber Kern- und 

Zell-theilung. ]ena. 

Vegetative cells 150-189/x x 180-240^, with plane end walls; 12 to 

14 chromatophores, making .5 turn; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; zygospores ellipsoid, 

about 120 /A X 158^1.; median spore wall smooth, brown. 

Switzerland, Zurich. 

102. Spirogyra jaoensis Randhawa 1938. Proc. Indian Acad. Set. 

8, pp. 358-59. 

Vegetative cells 44-56/A x 90-125/x, with plane end walls; 4 to 6 

chromatophores, making about .5 turn in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells somewhat in- 

flated on the conjugating side; zygospores ovoid, ju, 54-58 x 72-80 ju,; 

median spore wall smooth, brown. 

India, Fyzabad, November, 1936. 

This species differs very little from S. emilianensis (No. 90). It was 

named for Chin-Chih Jao, who has contributed not only numerous descrip- 

tions of new Zygnemataceae, but excellent drawings of intricate spore wall 

structures. 

103. Spirogyra baileyi Schmidle 1896. Flora. 82, pp. 302-3, PI. 9, 

Fig. 2. 

Vegetative cells 20-24 /x ^ 128-200 as with plane end walls; 2 chromatophores, 


by both gametangia; fertile cells inflated to /.i; 32 zygospores ellipsoid, 

28 /x X 48-50/^1; median spore wall smooth. (PI. XXVIII, Fig. 7.) 

Australia, Queensland. 

104. Spirogyra buchetii Petit 1913. Bull. soe. hot. de Franee. 

60, pp. 40-43. 

Vegetative cells 44-48 /a x 100-140 ju, with plane end walls; 2 chromatophores, 

making 2.5 to 4 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells shortened and inflated to 51^1; 

zygospores ellipsoid with rounded ends, variously placed in the fertile 

cells giving the appearance of being polymorphic, 48-51 /x x 72/A; me- 

dian spore wall smooth, yellow. 

United States: Indiana, Sullivan County (Ben Smith Coll.). 

Morocco, Tangier; China, Shantung (Li Coll.). 

105. Spirogyra bichromatophora (Randhawa) Transeau 1944. 

Ohio Jour. Sci. 44, p. 243. Proc. Indian Acad. Sci. 8, 

pp. 353-54, Fig. 48. 1938 (as S. gallica var. bichromatophora).

178 

ZYGNEMATACEAE 

Vegetative cells (xy-yîi x 96-160/^1, with plane end walls; 2 chro- 

matophores, making 4 to 6 turns; conjugation scalariform; large tubes 

formed by both gametangia; fertile cells cylindric or enlarged; zygospores 

ellipsoid, 54-60^ x 80-90/'; median spore wall smooth, brown. 

(PI. XXVIII, Fig. 6.) 

India, Fyzabad, May, 1938. 

106. Spirogyra RHizoiDES RandHawa 1938. Proc. Indian Acad. 

Sci. 8, pp. 354-56. 

Vegetative cells 26-28/^ x 75-125/11, with plane end walls; chromatophores 

2-3, making 1-2 turns in the cell; rhizoids well developed, 

made up of i or 2 cells with chromatophores; conjugation scalariform; 

tubes formed by both gametangia; fertile cells slightly inflated; zygo- 

spores ovoid, 36-38 /x X 52-58 /i; median spore wall thick, smooth, pale 

yellow. 

India, Hoshiarpur, March, 1930. 

In the original description, the median spore wall is given as "bluish." 

This appearance may have resulted from diffraction of light. I did not find 

it in the specimens examined. 

107. Spirogyra dubia Kiitzing 1855. Tabulae phycologicae. 5, 

p. 8, PI. 24, Fig. 4. 

Vegetative cells 40-50 i". x 60-250 m, with plane end walls; 2 to 3 

chromatophores, making 2 to 8.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated; zygospores ovoid, 

/li 42-50 X 54-67 /x; median spore wall yellow-brown, smooth. (PI. 

XXVIII, Fig. 8.) 

United States: Iowa; Illinois; Michigan; Pennsylvania; Massachusetts. 

Europe; Australia; South Africa; China. 

108. Spirogyra puncticulata Jao 1935. Trans. Amer. Micros. Soc. 

54, p. 4, PI. I, Fig. 9. 

Vegetative cells 1 6-22/1 x ft, 48-240 with plane end walls; filaments 

attached by rhizoids; chromatophores 2, rarely 1, making 1.5 to 5 turns 

in the cell; conjugation scalariform; tubes formed by both gametangia; 

fertile cells fusiform or cylindrically inflated to 29-36 /t; zygospores 

ovoid, 25-32/1 x 41-58/1; median wall densely punctate, yellow. (PI. 

XXVIII, Fig. 9.) 

United States: Massachusetts, Woods Hole. 

109. Spirogyra aequinoctialis G. S. West 1907. Jour. Linn. Soc. 

of London Bot. 38, p. 105, PI. 5, Figs. 1-2. 

Vegetative cells 23-25/1 x 90-150/', with plane end walls; 3 (rarely 

2) chromatophores, making 1-1.5 turns; conjugation scalariform; tubes

SPIROGYRA 179 

formed by both gametangia; fertile cells inflated, oblong; zygospores 

ovoid, or oblong-ovoid, 41-43 /^ x 52-71 /i.; median wall densely scrobic- 

ulate. (PI. XXVIII, Fig. 10.) 


Central Africa. 

1 10. Spirogyra rhizopus Jao 1936. Amer. Jour. Bot. 23, p. 55, 

Figs. 10-12. 

Vegetative cells 25-32 /a x 80-250 m, with plane end walls; 2 chromatophores, 

making 1.5 to 4 turns; basal cell with much expanded and 

irregularly lobed holdfast; conjugation scalariform; tubes formed by 

both gametangia; fertile cells quadrangularly inflated, sometimes oblong 

in form, to 57^".; zygospores ellipsoid, 35-42;^. x 64-ioo/x; outer spore 

wall thick, lamellose, colorless; median spore wall brown, irregularly 

reticulate. (PI. XXVIII, Figs. 11-13.) 

China, Peiping, July, 1927. 

111. Spirogyra dictyospora Jao 1935. Sinensia. 6, p. 599, PL 8, 

Fig. 84. 

Vegetative cells 28-32 /ax 55-144M, with plane end walls; chroma- 

tophores 3, sometimes 2, making 2-5 turns in the cell; conjugation 

scalariform; tubes formed by both gametangia; fertile cells enlarged up 

to /a; 

55 zygospores ovoid, 41-55 /x x 61-103 ft; median spore wall retic- 

ulate, yellow to yellow-brown. (PI. XXVIII, Fig. 14.) 

China, Chungking, February, 1930. 

112. Spirogyra natchita Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 225. 

Vegetative cells 32-36^1 x 120-200 ju, with plane end walls; i to 3 

(mostly 2) chromatophores; conjugation scalariform; tubes formed by 

both gametangia; fertile cells inflated to 62 /a; zygospores ovoid,

i8o ZYGNEMATACEAE 

114. Spirogyra schmidtii W. & G. S. West 1902. Bot. Tidsskrift. 

24, p. 161, Figs. 43-45. 

Vegetative cells 30-35/x x 210-350 m, with plane end walls; 2 to 3(4) 

chromatophores, making 2.5 to 4 turns; fertile cells inflated to 59/x; 

conjugation scalariform; tubes formed by both gametangia; zygospores 

ellipsoid, 4^-46/v. x 8(S-ii8/a; median spore wall yellow-brown, scrobic- 

ulate. (PI. XXVIII, Figs. 19-20.) 

United States: Texas and Florida. 

Slam, Koh Chang. 

The conjugating tubes frequently appear to have been formed by the 

male gametangium, due to the growth of the wall of the receptive gametangium. 

115. Spirocyra miamiana Taft 1944. Ohio Jour. Sci. 44, p. 238. 

Vegetative cells 20-25/'. x 1 50-340 /j., with plane end walls; 3 chromatophores 

(rarely 2), making 1.5 to 5 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells enlarged to /a, 41 length 

71 to 172/1; zygospores ellipsoid to cylindric-ellipsoid, ô-:5g/'. x 92/x; 

median spore wall composed of 2 layers; the outer layer wrinkled; the 

inner layer finely scrobiculate, yellow-brown at maturity. 

water. 

United States: Florida, Miami Beach and Winter Park. 

This species is at first attached to various underwater objects in flowing 

116. Spirogyra smithii Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 225. 

Vegetative cells 30-35 /^ x 220-360^1, with plane end walls; 3 to 4 

chromatophores, making i to 3 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells enlarged; zygo- 

spores ellipsoid, 45-52 /j. x 75-102 /x; median spore wall yellow-brown, of 

2 layers—outer, thin, wrinkled; inner, reticulate. (PI. XXVIII, Figs. 

17-18.) 

United States: Arkansas to Texas, east to New York and Florida. 

Named for Professor Ben H. Smith, Indiana State Teachers College at 

Terrc Haute, who collected the type specimens, and added many new 

records to the Indiana algal flora. 

117. Spirogyra chungkingensis Jao 1935. Sinensia. 6, p. 600, PI. 8, 

Figs. 85-86. Amer. Jour. Bot. 23, p. 58. 1936. 

Vegetative cells 22-26/J. x 80-170/A, with plane end walls; 3 chro- 

matophores, making i to 3 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; fertile cells inflated; zygospores 

ellipsoid, 35-39/^ X 54-68 m; median wall of 2 layers, of which the outer

SPIROGYRA i8i 

is thin, brownish and wrinkled, the inner, brown, and irregularly retic- 

ulate. (PI. XXIX, Figs. 1-2.) 

China, Chungking, August, 1930. 

118. Spirogyra orientalis W. & G. S. West 1907. Ann. Roy. Bot. 

Gard., Calcutta. 6, p. 186. 

Vegetative ceils 30-31 /^ x 90-1 60 /x, with plane end walls; 3 chro- 

matophores, making i to 1.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated, 57-65/^; zygospores 

ellipsoid, more or less pointed, 38-42^1 x 61-67 /a; niedian spore wall 

minutely scrobiculate, brown. (PI. XXIX, Fig. 3.) 

United States: Michigan, Cheboygan County (Taft Coll.). 

Burma; China, Yunnan (Li Coll.). 

119. Spirogyra subcylindrospora Jao 1935. Sinensia. 6, p. 598, 

PL 7, Figs. 79-80. 

Vegetative cells 25-32 ju x 96-228 /a, with plane end walls; 2 to 3 

(rarely 4) chromatophores, making i to 1.5 turns in the cell; conjuga- 

tion scalariform; tubes formed by both gametangia; fertile cells cylin- 

dric or enlarged; zygospores ellipsoid to cylindric-ellipsoid with 

rounded ends, 32-38 ju. x 58-96 /x; median spore wall brown, thick, retic- 




120. Spirogyra castanacea G. C. Couch 1944. Ohio Jour. Set. 

44, p. 277. 

Vegetative cells 34-37 M x 100-173 /x, ^^^^ plane end walls; 2 to 3 

chromatophores, making 2 to 3 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; receptive cell inflated on both 

sides; zygospores mostly broadly ellipsoid, rarely ovoid, 48-52 /x x 

69-73 /x; median spore wall chestnut brown, strongly reticulate. 

United States: Arkansas, Boston Mountain region. 

121. Spirogyra mienningensis Li 1940. Bull. Fan Mem. Inst. 


Vegetative cells 42-48 p. x 102-208 m, with plane end walls; chromatophores 

2 or 3, making 1-4 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells inflated up to 

74 m; zygospores ellipsoid, 52-59 /a x 70-88 jU.; outer spore wall of 2 layers, 

the outermost thin, smooth, transparent; the inner, thin and wrinkled; 

median spore wall granulose to verrucose, yellow-brown at maturity. 

(PI. XXIX, Fig. 6.) 

China, Yiinnan, Mienning, December 10, 1938.


122. Spirogyra shantungensis Li 1936. Bull. Fan Mem. Inst. 


Vegetative cells 46-52/1 x 1S4-320/1, with plane end walls; chromatophores 

3, making 2 to 4 turns in the cell; conjugation scalariform; 

tubes formed by both gamctangia; fertile cells inflated up to 70/1 and 

shortened; zygospores ellipsoid, with somewhat rounded ends, 4(S-56m x 

96-140 /bi; median spore wall double, outer nearly colorless, wrinkled; 

inner, brown, finely and irregularly reticulate. (Pi. XXIX, Fig. 7.) 

China, Tsingtao, Shantung, October, 1934. 

123. Spircx^yra braziliensis (Nordstedt) Transeau 1915. Ohio 

Jour. Sci. 16, p. 26. Wittrock and Nordstedt Algae Ex- 

siccatae, No. 360, as S. lineata var. braziliensis. 

Vegetative cells 50-60 /a x 125-300 jla, with plane end walls; 3 chromatophores, 


by both gametangia; fertile cells cylindric, shortened; zygospores elUp- 

soid, ju. 54-60 X 80-90^1; median spore wall minutely verrucose, yellowbrown. 

United States: Texas; Iowa; Mississippi. 

South America; China, Shantung. 

124. Spirogyra pulchrifigurata Jao 1935. Sinensia. 6, p. 601, 

PI. 8, Figs. 91-92. Amer. Jour. Bot. 23, p. 57, Figs. 15-17. 

1936. 

Vegetative cells 42-58 /^ x 64-192/^, with plane end walls; 3 to 4 


formed by both gametangia; fertile cells inflated up to 83/x; zygospores 

ellipsoid, with more or less rounded ends, ju. 48-64 x 70-109 û; median 

spore wall yellow-brown, irregularly reticulate. (PI. XXIX, Figs. 8-9.) 

United States: Louisiana (Taft Coll.). 

China, Szcchvvan, February, 1930. 

125. Spirogyra torta Blum 1943. Amer. Jour. Bot. 30, p. 783, 

Figs. 3-5- 

Vegetative cells 49-56/1 x 270-600/1, with plane end walls; 3 to 5 

chromatophores, making i to 4 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells cyUndric or 

enlarged; zygospores ellipsoid, 67-72/1 x 11 0-1 35/1; outer spore wall 

wrinkled, loose; median spore wall dark yellow, conspicuously pitted- 

reticulate. (PI. XXIX, Fig. 10.) 

United States: Massachusetts, Trout Pond, Megansett, July 27, 1942. 

126. Spirogyra quadrilaminata Jao 1935. Sinensia. 6, p. 600,

SPIROGYRA 183 


1936. 

Vegetative cells 38-581". x 112-256^1., with plane end walls; 3 to 4 

chromatophores, making i to 3.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cyHndric; zygospores ellipsoid 

to cylindric-ellipsoid, with more or less rounded ends, 43-54 ;" x 64-102^1; 

median spore wall of 2 layers; outer, brown and densely wrinkled; 

inner, brown, finely punctate, and at times finely and irregularly retic- 


United States: Florida; Tennessee; Texas. 

Puerto Rico; Brazil; China, Szechwan. 

127. Spirogyra rhizobrachialis Jao 1935. Sinensia. 6, p. 599, 


1936. 

Vegetative cells 40-45 /a x i 14-240 /x, with plane end walls; 3 to 5 

chromatophores, making 1.5 to 2.5 turns; in some portions of the filament 

each sterile cell produces a lateral rhizoid-shaped attachment with 

a more or less lobed hapteron; conjugation scalariform; tubes formed 

by both gametangia; fertile cells cylindric, sometimes shortened and en- 

larged; zygospores ellipsoid with more or less rounded ends, 38-60/^ x 

58-100 ju.; median spore wall yellow-brown, finely and irregularly retic- 



China, Chungking, February, 1930. 

128. Spirogyra paraguayensis Borge 1903. ArJ{. Bot. 1, p. 280. 

Vegetative cells 41-45;". x 80-200 ;U., with plane end walls; 3 to 4 

chromatophores, nearly straight, or making .5 turn; conjugation 

scalariform; tubes formed by both gametangia; fertile cells cylindric, 

shortened; zygospores ellipsoid, 37-42 fi x 58-65/^; median spore wall 

irregularly corrugate, yellow-brown. (PL XXIX, Figs. 17-18.) 

South America, Paraguay. 

129. Spirogyra subreticulata Fritsch 1921. Trans. Roy. Soc. S. 

Africa. 9, p. 48. 

Vegetative cells 50-54 /-


130. Spirogyra minor (Schmidle) Transeau 1944. Ohio Jour. Sci. 

44, p. 243. Schmidle. Hedwigia. 40, p. 46 (as S. fnalmeatia 

var. minor). 

Vegetative cells 55-60/Li x 150-300/^; 3 (rarely 4) chromatophores; 

conjugation scalariform; tubes formed by both gamctangia; fertile cells 

cylindric; zygospores ellipsoid, 50-60 /j. x 90-1 80 /a; median spore wall 

irregularly reticulate, yellow-brown. 

United States: Indiana (Ben Smith Coll.); Mississippi, Jackson; Texas 

(Davidson Coll.). 

Brazil; South Africa (Stephens Coll.); China, Szechwan (Li Coll.). 

This species name occurred in two editions of my mimeographed key 

to this genus where the date was given as 1925. There was no formal publication 

in a journal until 1944. Between these two dates all the above 

records accumulated. 

131. Spirogyra brunnea Czurda 1932. Siisswasserfiora Mittel- 

europa. 9, p. 197. Fritsch & Rich. Trans. Roy. Soc. S. 

Africa. 18, p. 51. 1929 (as S. reinhardii var. africana). 

Vegetative cells 56-71 /x x 85-280 /a, with plane end walls; 3 to 5 


formed by both gametangia; fertile cells shortened, and slightly inflated 

on both sides; zygospores ovoid, 55-66 /x x /x; 73-94 median spore wall 

brown, intricately reticulate. (PI. XXX, Figs. 1-2.) 

South Africa, Transvaal and Griqualand. 

132. Spirogyra scripta Nygaard 1932. Trans. Roy. Soc. S. Africa. 

20, p. 144, Fig. 48. 

Vegetative cells 51-64/x x 220-300^^, with plane end walls; 4 to 5 

chromatophores, making about 2 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated to Gy-yi /x, shortened; 

zygospores ellipsoid, more or less pointed, 54-60 /a x 91-107 m; median 

spore wall brown, with an intricate pattern of branched, short, dark 

crevices and corrugations. (PI. XXX, Figs. 3-4.) 

South Africa, Transvaal. 

133. Spirogyra fluviatilis Hilse 1863. In Rabenhorst's Algen Eu- 

ropas, No. 1476. Flora Europaea Algarum. 3, p. 243. 1868. 

Wolle. Freshwater Algae, p. 216, PI. 136, Figs. 1-3. 

Vegetative cells 30-45^4 x 70-240^1, with plane end walls; 3 to 4 

chromatophores, making 1.5 to 3.5 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells shortened and inflated to 

70/1; zygospores ovoid, 47-85 /x x 68-1 i0)u.; median spore wall brown, 

corrugate, or finely wrinkled. Remarkable branched rhizoids develop 

from some of the cells. (Fl. XXX, Fig. 5.)

SPIROGYRA 185 

United States: Widely distributed from Colorado to the east coast. 

Germany and France; widely reported in other countries but not neces- 

sarily this species; China and India. 

This species is frequent in streams and ponds in the northern Central 

States, attached to underwater objects at first, later floating free. Although 

described by Hilse in 1863, it was not reported in fruit until 1887 by WoUe. 

Zygospores were described by Borge from the upper Rhine region in 1894. 

These two publications establish the above description for S. fiuviatilis. 

Under this name Czurda (1932) described two forms of different dimensions 

with ellipsoid spores and 3-5 chromatophores and the tube formed by 

the male cell. His illustration, however, has 2 chromatophores and the tubes 

are formed by both gametangia. These plants evidently belong near S. 

smithti (No. 116). Krieger follows Czurda's description. 

134. Spirogyra africana (Fritsch) Czurda 1932. Siisswasserflora 

Mitteleuropa. 9, p. 201. 

Vegetative cells 50-60 /a x i 50-500 /x, with plane end walls; 3 to 4 


formed by both gametangia; receptive cells enlarged or inflated on both 

sides up to 96 /x; zygospores ovoid, 60-67 /a ^ 78-90 /x; median spore wall 

brown, irregularly and shallowly corrugate. 

Africa, Cape Colony; Guatemala (Kellerman Coll.). 

Very similar to 5. fiuviatilis, but has larger dimensions throughout. 

135. Spirogyra notabilis Taft 1944. Ohio Jour. Sci. 44, p. 238. 

Vegetative cells y>-^JlJ^ x 92-230 /x, with plane end walls; 2, 3, or 4 

chromatophores, making i to 3 turns in the ceil; at conjugation the cell 

walls are notably thickened; conjugation scalariform between short 

gametangia; tubes formed by both gametangia, but more by the male; 

receptive gametangia enlarged near the spore; zygospores ovoid, 48-57 ^tx 

X 78-105^1; median spore wall of 2 yellow-brown layers, of which the 

outer is conspicuously punctate, the inner, reticulate and finely 

verrucose. 

United States: Texas, Austin, April 19, 1938. 

The layers of the median wall are distinct and are among the most 

beautifully ornamented walls in the genus. 

136. Spirogyra grossii Schmidle 1901. Allgem. Bot. Zeitschr. 7, 

P-3- 

Vegetative cells 40-42 /a x 50-1 20 /a, with plane end walls; 3 chro- 

matophores, making 2 to 4 turns in the cell; conjugation scalariform; 

tubes apparently formed by the male gametangia; fertile cells inflated 

to ju.; 64 zygospores ovoid, ju, 43-51 x 64-118 /x; median spore wall irreg- 

ularly corrugate. (PI. XXX, Fig. 6.) 

Yugoslavia; Manchuria; India.


137. Spirocyra ovigera Montague 1850. Afi?i. set. nat. p. 305. 

Sylloge generum specierumque, Paris, p. 463. 1856. 

Vegetative cells 38-42 /u. x 60-280/1, with plane end walls; 3 chro- 

matophores, making 2 to 3 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; fertile cells inflated; zygospores 

ovoid, sometimes nearly ellipsoid, 45-52 /x x 75-100 m; median spore wall 

granulose, brown. 

United States: Texas (Davidson Coll.). 

South America, French Guiana. 

138. Spirogyra novae-angliae Transeau 1915. Ohio Jour. Sci. 

16, p. 26. 

Vegetative cells 48-60 /a x 150-390/'-, with plane end walls; 3 to 5 


fertile cells cyHndric or enlarged; tubes formed by both gametangia; 

zygospores ovoid, 50-65/1 x 70-120 /a; median spore wall yellow, retic- 

ulate and finely punctate. (PI. XXX, Fig. 7.) 

United States: Iowa and Wisconsin to Louisiana, and eastward 10 


139. Spirogyra anomala Rao 1937. Jour. India?! Bot. Soc. 16, 

p. 285. 

Vegetative cells 108-125/1 x 72-165/1, with plane end walls; chromatophores 

5 to 10; conjugation scalariform; tubes formed by both 

gametangia; fertile cells cylindric; zygospores ellipsoid, more or less 

pointed, 73-90/t x io8-i38(-i65)/i; median wall thick, brown, and 

finely reticulate. 

India: Sarnath, U.P. 

140. Spirogyra verruculosa Jao 1936. Amer. Jour. Bot. 23, p. 58. 

Vegetative cells 105-120/1. x 259-420 /t, with plane end walls; 5 chromatophores, 


by both gametangia; fertile cells cylindric or slightly enlarged; zygo- 

spores eUipsoid to ovoid, 1 05-1 20/1 x 168-220 /a; median spore wall dark 

brown, distinctly verrucose. (PI. XXX, Figs. 8-10.) 

China, Mangchovv, June, 1929. 

141. Spirogyra malmeana Hirn 1896. Wittrock and Nordstcdt 

Algae Exsiccatae, No. 1375. 

Vegetative cells 76-91 /t x 160-300/1, with plane end walls; 3 to 4 


formed by both gametangia; fertile cells cylindric; zygospores ellipsoid,

SPIROGYRA 187 

65-83 /x X 75-1 00 /x; median spore wall yellow-brown, irregularly retic- 

ulate. (PI. XXX, Figs. 14-16.) 

Brazil, Mato Grosso, May, 1894. 

142. Spirogyra propria Transeau 1915. Ohio Jour. Sci. 16, p. 25. 

Vegetative cells 60-68 /x x 80-150)11, with plane end walls; 3 chro- 

matophores, making .5 to i turn; conjugation lateral; tubes formed by 

both gametangia; fertile cells cylindric; zygospores ellipsoid, 42-60 |U x 

80-120^; median spore wall irregularly pitted, yellow-brown. 

United States: Illinois; Kentucky (Mclnteer Coll.). 

In the collections seen the spores were uniformly oriented diagonally in 

the short receptive gametangia. 

143. Spirogyra trachycarpa Skuja 1932. Acta Horti Bot. Univ. 

Latviensis. 7, p. 63, Fig. 82. 

Vegetative cells 1 10-123 /a x i 10-500 /x, with plane end walls; 4 to 

6(-8) chromatophores, making i to 2.5 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells inflated on the inner 

side; male gametangia 87-1 76 /x long, female, 1 19-252 /x; zygospores 

broadly ellipsoid, 87-108 /x x ii7-i72(-204)/x; median spore wall thick, 

irregularly scrobiculate, color not given; outer spore wall thick, hyaline. 

Latvia, 

144. Spirogyra ghosei Singh 1938. Jour. Indian Bot. Soc. 17, 

p. 382. 

Vegetative cells 100-105 ju, ^ 225-390 /x, with plane end walls; chromatophores 

6 to 7; conjugation scalariform; tubes formed by both gam- 

etangia; fertile cells cylindric; zygospores ovoid, 90-103 /x x 105-120 /x; 

median spore wall thick, brown and closely reticulate. (PI. XXV, 

Fig. 12.) 

India, U.P., Gorakhpur, November 8, 1937. 

145. Spirogyra punctulata Jao 1936. Amer. Jour. Bot. 23, p. 57, 

Figs. 13-14. 

Vegetative cells 70-83^ x 105-315)^, with plane end walls; filaments 

usually curved; 3 to 7 chromatophores, making .5 to 1.5 turns; con- 

jugation scalariform; tubes formed by both gametangia; fertile cells 

cylindric; zygospores ellipsoid with pointed ends, 64-74 /x ^ 83~i79/^; 

median spore wall thick, finely punctate, and yellow at 

XXX, Figs. 11-13.) 

maturity. (PI. 

China, Poatin, August, 1929. 

Jao in 1939 described a variety macrospora, with 4 chromatophores and 

thicker spores.


146. Spirogyra cylindrospora W. & G. S. West 1897. Jour. Bot. 

35, p. 42. 

Vegetative cells 70-77 /x x 100-300 /n, with plane end walls; 4 chro- 

matophores, making i to 3 turns; conjugation scalariform and lateral; 

tubes formed by both gametangia; fertile cells cylindric; zygospores 

cylindric-ovoid, 70-77/1 x 78-98 /x; median spore wall yellow, punctate- 

scrobiculate, thick. 

Central Africa. 

147. Spirog\tia echinospora Blum 1943. Amer. Jour. Bot. 30, 

p. 783, Figs. 1-2. 

Vegetative cells 66-72 /n x 50-125/^, with plane end walls; 6-7(-8) 

chromatophores, making .5 to 1.5 turns in the cell; conjugation scalariform; 

tubes wide and formed by both gametangia; fertile cells more 

or less inflated on the conjugating side; zygospores ovoid, 67-82 m x 

98-150/x; median spore wall thick, brown-black, cchinate. (PI. XXX, 

Figs. 17-18.) 

United States: New Hampshire. 

148. Spirogyra diluta Wood 1869. Proc. Amer. Phil. Soc. (1869), 

p. 139. Phycoth. Bor.-Amer., No. 513. 

Vegetative cells 70-85/1 x 80-160/1., with plane end walls; 5 to 8 

chromatophores, straight or making i turn; conjugation scalariform; 

tubes formed by both gametangia; fertile cells enlarged or inflated on 

the inner side; zygospores ovoid, 66-90/1 x 90-130/1; median spore wall 

chestnut brown, verrucose-reticulate to verrucose. (Pi. XXX, Figs. 

19-20.) 

United States: Illinois to Massachusetts and Connecticut. 

In Figure 19 note short gametangia with spores oriented at right angles 

to the filaments. Similar gametangia occur in species Numbers 141, 147, 

149. 150, 151, also in Numbers 171, 176, and 177. 

149. Spirogyra echinata Tiffany 1924. Ohio Jour. Sci. 24, p. 180, 

PI. I, Fig. I. 

Vegetative cells 88-96/t x 84-106/1, with plane end walls; 4 to 7 


formed by both gametangia; fertile cells shortened and inflated on the 

conjugating side; zygospores ovoid, 68-85/1 x 76-120/1, often placed 

transversely to the filament; median spore wall reticulaie-echinate, 

brown. (PI. XXXI, Figs. 1-2.) 

United States: Iowa, Montgomery. 

South Africa (Stephens Coll.).

SPIROGYRA 189 

150. Spirogyra reinhardii Chmielevski 1903. In Borge, Siisswas- 

serflora Deutschland. 9, p. 31, Fig. 41. 

Vegetative cells loS-iiy/x x 85-310/^, with plane end walls; 4 to 6 

chromatophores, making .5 to 2 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated on the conjugating 

side; zygospores ovoid, 78-100 /x x 115-175^^,; median spore wall chestnut 

brown, irregularly reticulate. (PI. XXXI, Figs. 3-5.) 

Russia, Kharkov; Brazil. 

151. Spirogyra hunanensis Jao 1940. Sineftsia. 11, p. 297, PL 4, 

Figs. 4-5. 

Vegetative cells 88-1 00 /x x 75-210 /x, with plane end walls, and 8-10 

nearly straight or slightly spiraled chromatophores; conjugation scalar- 

iform; tubes formed by both gametangia; receptive gametangia inflated 

on the conjugating side up to 150/J.; zygospores ovoid, 88-105 m ^ 

i42-i63/(.; median spore wall yellow-brown, reticulate and verrucose, 

with verrucae up to 13 m in length. (PI. XXXI, Fig. 6.) 

China, Hunan. 

SPECIES WITH SPORES LATERALLY COMPRESSED 

152. Spirogyra discoidea Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 228. 

Vegetative cells 39-42 /x x 72-11 /x, 5 with plane end walls; i chromatophore; 


receptive gametangia enlarged or inflated toward the middle; zygo- 

spores compressed-globose, 40-44^1 x 56-65 /x; median spore wall brown, 

smooth. (PI. XXXI, Fig. 7.) 

South Africa, Cape Town (E. Stephens Coll.). 

153. Spirogyra sphaerospora Hirn 1895. Acta Soc. pro Fauna et 

Flora Fennica. 11 (10), p. 10. 

Vegetative cells /x 43-45 x 1 80-320 /x, with plane end walls; i chromatophore, 

making about 3 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells greatly inflated (to 93-100 /x) 

toward the middle; zygospores compressed-globose, 85-q5/x in diam- 

eter; median spore wall yellowish-brown, smooth. (PI. XXXI, Fig. 9.) 

Finland, Lojo. 

Cedercreutz {Mem. Soc. pro Fauna et Flora Fennica, 11, p. 131) gives 

evidence from examination of material from Lojo that Hirn's species is 

identical with .S. pellucida (No. 156). This species is, therefore, listed here 

tentatively on the basis of the single chromatophore. The published figures 

of these 2 species are certainly very similar. Hirn may have been in error 

concerning the number of chromatophores—a very unusual error for him.

190 

ZYGNEMATACEAE 

154. Spirogyra sinensis Li 1933. Ohio Jour. Set. 33, p. 153, PI, i, 

Figs. 7-8. 

Vegetative cells 22-24/i. x 115-136/J., with plane end walls; 2 to 4 


tubes formed by both gametangia; fertile cells inflated toward the middle 

to about 50/t; zygospores lenticular, 3^-45/' in diameter; median 

spore wall smooth, brown. (PL XXXI, Fig. 10.) 

China, Hangchow. 

155. Spirogyra frankliniana Tiffany 1934. Trajis. Amer. Micros. 

Soc. 53, p. 225. Ohio Jour. Sci. 24, p. 65. 

Vegetative cells 32-36 /x x 80-120/1, with plane end walls; 3 to 4 

chromatophores, making i to 3 turns in the cell; conjugation scalariform; 

tubes formed by both gametangia; fertile cells inflated toward 

the middle; zygospores lenticular, 40-56/J. in diameter; median spore 

wall smooth, brown. 

United States: Ohio, Franklin County, Baumgartner's Lake. 

156. Spirogyra pellucida (Hassall) Kiitzing 1849. Species Algarum, 

p. 439. Hassall. History of British Freshwater 

Algae, p. 143, Pi. 25, Figs. 1-2. 

Vegetative cells 40-50 ju. x 100-400111, with plane end walls; 3 to 4 

chromatophores, straight, or making .5 to 4 turns; conjugation scalariform; 

tubes formed by both gametangia; iêrtile cells inflated toward 

the middle; zygospores lenticular, 77-86 /x in diameter; median spore 

wall smooth, brown. (PI. XXXI, Fig. 8.) 

United States: Iowa (Prescott Coll.), 

England; Finland; China. 

157. Spirogyra colligata Hodgetts 1920. Ann. Bot. 34, p. 523, 

PI. 22. 

Vegetative cells 29-40/1 x 240-640/1, with conspicuous collars between 

the cells; 4 to 6 chromatophores, usually 5, making .5 to 2.0 turns 

in the cell; conjugation scalariform, lateral, and terminal; tubes formed 

by both gametangia; fertile cells inflated at the middle up to 90-100/1; 

zygospores lenticular to lenticular-globose, 50-80 ( /i -90 ) in diameter; 

median spore wall verruculose, brown. (PI. XXXI, Figs. 11-13.) 

United States: Indiana, Laporte County (Britten Coll.), May 13, 1939. 

England. 

158. Spirogyra majuscula Kiitzing 1849. Species Algarum, p. 441. 

Vegetative cells 50-80/1 x 80-500/1, with plane end walls; (3-) 5 to 

8 chromatophores, straight or making .3 turn; conjugation scalariform 

and lateral; tubes formed by both gametangia; fertile cells shortened.

SPIROGYRA 191 

cylindric or slightly inflated; zygospores lenticular, '^y-Sin x 45-60/1; 

median spore wall brown, smooth; aplanospores similar but smaller. 

(PL XXXI, Figs. 14-15.) 

United States: Very abundant in late spring and summer throughout 

the northcentral states; also reported from Washington and Texas; and 

from the eastern states. New England to South Carolina. 

Europe; China; South Africa; Brazil; Uruguay. 

This is a complex group of elementary forms, differing in dimensions 

and numbers of chromatophores. However, among the many collections I 

have examined, the overlapping of form characteristics is so continuous from 

the smaller to the larger specimens that there seem to be no good bases for 

separation as varieties and forms. Czurda (1932, p. 204) discusses smaller 

and larger forms. Conard (Beih. Bot. Zentralbl. 55, p. 184, 1936) proposed 

to remove certain of the species having lenticular spores from the genus 

Spirogyra under the generic name Degagnya. This proposal would require 

a restudy of all species of Zygnemataceae, since he introduces new criteria 

for the separation of genera. The species Conard designates as D. majuscida 

Conard is certainly not our species S. majuscula Kiitzing. 

In 1884 Professor C. E. Bessey reported finding this species conjugating 

with S. protecta. Conjugation occurred in both directions and the zygo- 

spores formed were similar to those of the female filament. 

159. Spirogyra submaxima Transeau 1914. Amer. Jour. Bot. 1, 

p. 295, PL 27, Figs. 3-4. 

Vegetative cells 70-110/1 x 100-300/1, with plane end walls; 8 to 9 

chromatophores making .1 to i turn; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric, enlarged, or slightly 

inflated; zygospores lenticular, 70-110/1 x 50-75/1; median spore wall 

brown, smooth. 

United States: Missouri and Mississippi eastward to Massachusetts. 

China; India. 

Found hybridizing with S. maxima at Charleston, Illinois. 

160. Spirogyra glabra Czurda 1932. Siisswasserflora Mitteleu- 

ropa. 9, p. 206, Fig. 222. 

Vegetative cells 145-153 /i x 120-220/1, with plane end walls; 7 chromatophores; 

conjugation scalariform; tubes formed by both gam- 

etangia; fertile cells cylindric; zygospores lenticular, about 120/1 x 170/1; 

outer spore wall about lo/i thick, colorless; median spore wall about 

20/1 thick, yellow-brown, smooth. (PL XXXI, Fig. 16,) 

Austria, Vienna. 

161. Spirogyra bellis (Hassall) Cleve 1868. Nova Acta Reg. Soc. 

Sci. Upsali. Ser. 3, 6, p. 18, PL 3, Figs. 2-5. 

Vegetative cells 65-80/1 x 90-350/1, with plane end walls; 5 to 6


chromatophores, making .i to i turn; conjugation scalariform; tubes 

formed by both gametangia; fertile cells shortened and inflated; zygo- 

spores lenticular, 60-90M x 48-60/1; median spore wall brown, irreg- 

ularly pitted. (PI. XXXI, Figs. 17-1S.) 

United States: Missouri to Massachusetts and Florida. 

Europe; Australia; South Africa. 

162. Spirogyra moebii Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 225. S. maxima var. minor Mocbius. Flora. 75, 

p. 421. 1892. 

Vegetative cells So-iiy ix x 130-240 /.i, with plane end walls; 6 to 8 


formed by both gametangia; fertile cells cylindric; zygospores lentic- 

ular, 74-100 /x X 56-65 ju; median spore wall yellow-brown, reticulate. 

United States: Oklahoma (Taft Coll.). 

Europe; Australia, Queensland. 

163. Spirogyra oblata Jao 1936. Amer. Jour. Bot. 23, p. 58, 

Figs. 29-31. 

Vegetative cells 96-11 m x 80-256/', with plane end walls; 9 to 13 

chromatophores, nearly straight, or making up to .6 turn; conjugation 

scalariform; tubes formed by both gametangia; fertile cells shortened, 

cylindric; zygospores lenticular, 93-106A1 x 64-70/

SPIROGYRA 193 

by both gametangia; fertile cells cylindric; zygospores lenticular to 

compressed-ovoid, 102-126 i-t x 140-154 /a x 72-97 a^; median spore wall 

brown, smooth. (PL XXXII, Fig. 5.) 

Russia, Bessarabia. 

166. Spirocyra azygospora Singh 1938. Jour. Indian Bot. Soc. 

17, p. 372. 

Vegetative cells 85-90 a^ x 270-300^1, with plane end walls; chromatophores 

5; conjugation unknown; reproduction by aplanospores 

which are compressed-globose, 71-77/^ x 60-67 /x; rnedian wall thick, 

brown, and smooth. (PL XLI, Fig. 16.) 

India, Gorakhpur, U.P., October, 1936. 

Fig. F.—Vegetative cell of Spirogyra crassa. The average length is usually about the 

same as the diameter, and conjugating filaments always have some cells about one-half 

the diameter. This cell has 8 chromatophores. 

167. Spirogyra crassa Kiitzing 1843. Phycologia Generalis, p. 280, 

PL 14, Fig. 4. 

Vegetative cells 140-165 /x x 126-330 /a, with plane end walls; 6-12 


zygospores compressed-ovoid, 120-150 /x x 140-160 a

194 

ZYGNEMATACEAE 

Most of the early records were based on vegetative filaments. Found hybridizing 

with S. nitida at Starkville, Mississippi. Found conjugating with 

5. communis by Andrews, 191 1. 

168. SpmoG"iTiA MANORAMAE Randhawa 1938. Proc. Indian Acad. 

Set. 8, p. 360. 

Vegetative cells 80-90 /j. x 80-160 )u., with plane end walls; 7 to 10 

chromatophores, straight, or making .5 turn in the cell; conjugation 

scalariform; tubes formed by both gametangia; fertile cells more or less 

inflated; zygospores lenticular, 75-86 /^ x 58-80 /x; median wall yellowbrown, 

irregularly corrugate and finely verrucose-punctate. (PI. XXXII, 

Fig- 7-) 

India, Basti, Upper Punjab. 

169. Spirogyra jatobae Transeau 1938. Amer. Jour. Bot. 25, 

p. 527, Figs. 14-15. 

Vegetative cells 1 18-130 /j- x 108-500 m, with plane end walls and 

8-1 1 chromatophores, straight or making i turn in the cell; conjugation 

scalariform; tubes formed by both gametangia; receptive gametangia 

slightly inflated, especially on the conjugating side; zygospores com- 

pressed-spherical, 108-140 /i. x 78-90 i".; median wall yellow-brown, irreg- 

ularly and minutely verrucose. (PI. XXXII, Figs. 8-9.) 

Brazil, Jatoba, October 3, 1933 (Drouet Coll.). 

170. Spirogyra maxima (Hassall) Wittrock 1882. Bot. Notiser. 

P-57- 

Vegetative cells 1 18-140 /j. x 100-250 jh, with plane end walls; 6 to 7 

chromatophores, making .2 to .8 turn; conjugation scalariform; tubes 

formed by both gametangia; fertile cells cylindric; zygospores lentic- 

ular, 100-125 /x x 75-95iu^; median spore wall golden-brown, reticulate. 

(PI. XXXII, Figs. lo-ii.) 

United States: California; Wisconsin; and the eastern half of the 

United States. 

Europe; South America; Australia; India; China. 

Found hybridizing with S. submaxima (No. 159) at Charleston, Illi- 

nois. Woile collected specimens of S. maxima hybridizing with S. nitida. 

These were distributed as No. 541, in Wittrock and Nordstcdt's Algae 

Exsiccatae. 

171. Spirogyra heeriana Nageli 1849. In Kiitzing, Species Algarum, 

p. 442. Tabulae p/iycologicae. 5, PL 28, Fig. 3. 

Vegetative cells 130-150 /a x i 30-250 m, with plane end walls; about 

8 chromatophores, making .5 to i turn in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells not inflated,

SPIROGYRA 195 

although the tubes become very wide; zygospores lenticular, about i50A'in 

diameter; median wall yellow-brown, thick, with round brown 

papillae irregularly distributed over the surface. (PI. XXXII, Figs. 

12-13.) 

Austria, Vienna; France. 

172. Spirogyra crassiuscula (W. & N.) Transeau 1934. Ohio 

Jour. Sci. 34, p. 420. Wittrock and Nordstedt Algae 

Exsiccatae, No. 746. 

Vegetative cells 145-170/1 x 140-300 /

196 

ZYGNEMATACEAE 

iform; tubes formed by both gamctangia; fertile cells cylindric; zygo- 

spores compressed-ellipsoid, 120-140/1 x 145-255/i; median spore wall 

smooth, yellow-brown. (PI. XXXIII, Fig. i.) 

United States: Iowa; Illinois; Ohio. 

Resembles S. elUpsospora, but the form of the spores is quite distinctive. 

It should not be confused with S. crassa, as was done by Czurda 1932, page 

216, although on page 202 he republished the figures of the "crassoidea" 

spore (Fig. 217b) as that of S. elUpsospora, which further confused the iden- 

tity of this species. In i plane the spore is distinctly ellipsoid, in the plane 

at right angles the spore is ovoid. 

176. Spirogyra rectispira Merriman 1922 [Char, amend J. Amer. 

Jour. Bot. 9, p. 283. 

Vegetative cells 150-180 ju. x 75-320 /x, with plane end walls; 11-16 

chromatophores, straight or making .1 to i turn; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells cylindric or en- 

larged on the inner side; zygospores compressed-ovoid, 140-152/1 x 

168-185/i. X 110-130/^; median spore wall minutely vcrrucose, brown. 

United States: New York City, Van Cordandt Park. 

Original description is incorrect in several particulars. This description 

is based on the original material kindly sent me by Miss Merriman. 

PLANE END WALLS 

CONJUGATING TUBES BY MALE GAMETANGIA 

177. Spirogyra hydrodictya Transeau 1915. Ohio fonr. Sci. 16, 

p. 28. 

Vegetative cells 75-100 /j. x 210-360/'., with plane end walls; 7 to 10 

chromatophores, straight or making .1 to .5 turn; conjugation scalar- 

iform and lateral; tubes formed by the male gametangia; fertile cells 

shortened and enlarged, or slightly inflated; zygospores lenticular to 

lenticular-globose, So-120/^ x iio-195/t; median spore wall brown, 

pitted. (PI. XXXIII, Figs. 2-4.) 

United States: Illinois, Coffeen, Prairie Pond, May 23, 191 5. Great 

masses of the tangled filaments of this species were present on this date, but 

it was not found there again in subsequent years although it was searched 

for annually. 

178. Spirogyra texensis Taft 1944. 0/iio Jour. Sci. 44, p. 238. 

Vegetative cells 50-55/^1 x 90-530/'., with plane end walls; 3 to 5 

chromatophores, making 1.5 to 3.5 turns in the cell; conjugation scalar- 

iform; tubes formed by the male gametangia; fertile cells shortened 

and enlarged; zygospores ovoid, ()()-y6[i. x 99-124/1; outer spore wall 

transparent, irregularly corrugate; median wall yellow-brown, con- 

spicuously reticulate. (PI. XXXIII, Fig. 5.)

wall. 

United States: Texas, Karnac, April 27, 1938. 

SPIROGYRA 197 

In this collection the outer spore wall was much larger than the median 

179. Spirogyra taylorii Jao 1935. Trans. Amer. Micros. Soc. 54, 

p. 4, PL I, Figs. 2-3. 

Vegetative cells 12-16(1 x (48-) 70-193 ju,, with plane end walls; i 

chromatophore, making 2.5 to 6 turns in the cell; conjugation scalar- 

iform; tubes formed by the male gametangia; fertile cells inflated 

toward the middle and usually more on the conjugating side, up to 

33 /-i; zygospores ellipsoid, 19-29;". x 39-45 /x; median spore wall finely 

reticulate to punctate, yellowish-brown at maturity. (PI. XXXIII, 

Fig- 9-) 


The fertile cells are continuous in the filaments, not separated as in the 

next species. Named for W. R. Taylor, University of Michigan, author of 

Marine Algae of the Northeastern Coast of North America and many contributions 

to both fresh-water and marine phycology. 

180. Spirogyra liana Transeau 1934. Trans. Amer. Micros. Soc. 

53, p. 228. 

Vegetative cells 11-16/J. x 75-160/^1, with plane end walls; i chro- 

matophore, making 2 to 6 turns; conjugation scalariform and lateral; 

tubes formed wholly by the male gametangia; inflated single or paired 

fertile cells usually separated by i to 5 nonconjugating cells; zygospores 

ellipsoid, 23-^0 m x 35-50 m; median spore wall yellow, smooth. (PI. 

XXXIII, Figs. 1(^11.) 

China, Szechwan and Kiangsi; Sweden. 

Named for Liang Ching Li, Fan Memorial Institute, Peiping, China. 

This is one of the smallest of the species with plane end walls in which the 

conjugating tubes are formed by the male gametangia. In most of these 

species (Nos. 177 to 197), the conjugating cells are arranged singly or in 

pairs with one to several intervening nonconjugating cells. At the inception 

of conjugation, food substances accumulate in these gametangia and they 

become darker green and filled with starch grains. At the same time the 

intervening cells become lighter green and the chromatophores become 

thinner and narrower. This group of species may be designated the "punc- 

tata group" after the first of these species to be described. 

S. hydrodictya (No. 177) has these same characteristics and has in 

addition the compressed-spherical spores characteristic of the "majuscula 

group" of species. This species illustrates one of the difficulties in the path 

of anyone who attempts to subdivide the genus Spif-ogyra on the basis of 

tube formation or spore form. 

Among the replicate species of Spirogyra there is a corresponding group

198 

ZYGNEMATACEAE 

in which the tubes are similarly formed by the male cell, but the segregation 

ot reproductive and vegetative cells is not so evident. 

181. Spirogyra prescottii (Prescott) Transeau 1944. Ohio Jour. 

Set. 44, p. 243. Amer. Midland Naturalist. 27, p. 673, 

PI. 4, Figs. 15-17. 1942 (as S. collinsii var. minor). 

Vegetative cells 13-14/i. x 1 15-140 /i, with plane end walls; i chromatophore, 

loosely spiraled; conjugation scalariform; tubes formed by 

the male gametangia; fertile cells inflated to ^7îx\ zygospores ovoid to 

ellipsoid, 29 /^ x 39-40 /a; median spore wall coarsely punctate, yellow. 

United States: Massachusetts, Falmouth, July, 1933. 

The dimensions are so much smaller than those of S. collinsii that it 

seems better to separate it as a distinct species, although it is certainly very 

similar in other respects. Named for G. W. Prescott, State College, Mich- 

igan, author of many publications on fresh-water algae including Algae of 

Iowa. 

182. Spircx5yra chenii Jao 1935. Sinensia. 6, p. 587, PI. 4, Fig. 52. 

Vegetative cells 19-22 jia x 38-11 ju,, with plane end walls; i chromatophore, 

making i to 5 turns in the cell; conjugation lateral and 

scalariform; conjugating tubes formed by the male gametangia; fertile 

cells inflated up to ju, 42 usually separated by i or more sterile cells; 

zygospores ellipsoid, /u. 25-32 x 45-61 yu,; median spore wall smooth, yellow 

at maturity. (Pi. XXXIII, Fig. 14.) 


183. Spirogyra collinsii (Lewis) Printz 1927. Engler and Prantl. 

Pflazenfamilien. Second edition, 3, p. 371. Amer. Jour. 

Bot. 12, p. 351, 1925 (as Temnogyra eoUinsii). 

Vegetative cells 18-22/^ x 100-200/^, with plane end walls; i chro- 

matophore, rarely 2 in some cells, making from 3 to 9 turns in the cell; 

conjugation usually lateral, sometimes scalariform; tubes formed mostly 

by the male gametangia; fertile cells inflated, 25-39 ;u x 45-110 jli; zygospores 

ellipsoid, or sometimes ovoid, 26-37^ x 52-62 (-1 )u,; 10) median 

spore wall coarsely punctate, yellow. (PI. XXXIII, Figs. 12-13.) 

United States: Massachusetts, Woods Hole, July, 1922; Mississippi, 

Biloxi, February 14, 1934 (Hicks Coll.); Florida, Daytona, March 12, 1931 

(Tiffany Coll.), and Tarpon Springs, August 7, 1945 (R. K. Salisbury 

Coll.). 

This species is one of the most specialized of the "punctata group" in 

that the gametangia are much smaller than the vegetative cells, and most of 

the chromatophore passes into the gametangial end during cell division, 

leaving only a small portion in the sterile cell. This remnant is often flat 

and straight, or only slightly curved, as in Mougtotia. When I first saw 

the species in the Biloxi collections 1 took it to be a Temnogametum until I

SPIROGYRA 199 

found the earlier stages of conjugation. It is therefore easy to understand 

why Professor Ivey Lewis proposed a new genus for this species and gave it 

the name Temnogyra. The species is named in honor of Frank S. CoUins 

of Maiden, Massachusetts, who published The Green Algae of North 

America in 1909 and numerous other papers on fresh-water and marine 

algae. 

184. Spirogyra punctata Cleve 1868. Nova Acta Reg. Soc. Sci. 

Upsali. Ser. 3, 6, p. 23, PL 4, Figs. 1-4. 

Vegetative cells yu, 24-30 x 70-360 jti, with plane end walls; i chromatophore, 

making 3 to 8 turns in the cell; conjugation lateral and 

scalariform; tubes formed by the male gametangia; gametangia single, 

or in pairs, separated by much longer sterile cells in each filament; fer- 

tile gametangia inflated to /u.; 45 zygospores ellipsoid, 28-43 /a x 42-78 m; 

median spore wall coarsely punctate, yellow. (PL XXXIV, Fig. i.) 

United States: Iowa to Massachusetts and New Jersey. 

Reported from Europe, Afghanistan, China, and Australia. 

Some of the older records would now be changed to other species of the 

"punctata group" since they were probably made on the basis of the tubes 

and of the contrast between gametangia and sterile cells. The species 

described by Jao as S. collinsii var. ampla {Trans. Amer. Micros. Soc, 54, 

p. 2. 1935) seems to belong here, and I have used his drawing to illustrate 

this species. 

185. Spirogyra sirogonioides Hughes 1943. Abstracts of Doctoral 

Dissertations. The Ohio State University, 40, 1943. 

Vegetative cells 17-22 /^ x (60-) 160-220^1 with plane end walls; i 

chromatophore, making 3 to 6 turns in the cell; conjugation lateral and 

scalariform; tubes formed mostly by the male gametangia, sometimes 

becoming very broad at maturity; receptive gametangia inflated on the 

conjugating side; zygospores ellipsoid, 35-39 /^ x 58-67 /a; median wall 

yellow-brown, ornamented with variably shaped and irregularly dis- 

tributed scrobiculae. (PL XXXIII, Figs. 7-8.) 

Canada, Charleston, Queens County, Nova Scotia, July, 1941, and 1942. 

The specific name was suggested by the fact that occasional mature 

pairs of gametangia have the appearance of conjugated cells in Sirogonium. 

186. Spirogyra lushanensis Li 1938. Bull. Fan Mem. Inst. Biol. 

8, p. 92, PL 2, Figs. 4-5. 

Vegetative cells 17-23/^ x 84-1 ft, 58 with plane end walls; i chro- 

matophore, making 3.5 to 7 turns in the cell; conjugation scalariform; 

tubes formed wholly by the male gametangia; fertile cells inflated to 

38 ft and shortened; zygospores ellipsoid, 26-36^1 x 42-78 /x; median wall 

irregularly reticulate, yellow. (PL XXXIII, Fig. 6.) 

China, Kiangsi, Lushan, September, 1936.

20O ZYGNEMATACEAE 

187. Spirckiyra esthonica (Skuja) Czurda 1932. Siisswasserfiora 

Mitteleiiropa. 9, p. 180, Fig. 191. Acta Horti Bot. Unit/. 

Latuiensis. 3, p. 109 (as S. punctata var. esthonica). 

Vegetative cells 27-33^0. x 90-360 /a, with plane end walls; i chromatophore, 


tubes formed largely by the male gametangia; receptive gametangia 

inflated up to 60 /x; gametangia usually separated by sterile cells; zygospores 

ellipsoid, 39-50M x 64-115/it; median wall irregularly corrugate 

with minute punctations between the ridges. (PI. XXXIV, Figs. 2-3.) 

Estonia, July, 1927. 

188. Spirogyra suomiana Transeau 1934. Ohio Jour. Sci. 34, 

p. 420. Hirn, Karl E. Acta Soc. pro Fauna et Flora Fen- 

nica. 11 (10), p. 10, PL i, Fig. 3. 1895. 

Vegetative cells 33-40 m x 100-240 /a, with plane end walls; i chro- 

matophore, making several turns in the cell; conjugation scalariform; 

tubes formed by the male gametangia; receptive gametangia inflated to 

58-73 /x; gametangia separated by much longer sterile cells; zygospores 

ovoid, 45-53 A^ X 75-90 /m; median wall golden yellow, coarsely punctate. 

(PI. XXXIV, Fig. 4.) 

Finnish Lapland; China, Tsingtao (Li Coll.); Manchuria. 

189. Spirogyra punctiformis Transeau 1914. Amer. ]our. Bot. 

1, p. 294. 

Vegetative cells ly-Tpi*. x 120-390^1, with plane end walls; i or 2 

chromatophores, making 3 to 6 turns; conjugation scalariform; con- 

jugating tubes usually produced by the male gametangia; fertile cells 

in pairs or singly between vegetative cells, inflated to 45-50 a^; zygo- 

spores ovoid, 40-48 /x X 60-iiOiLi; median spore wall yellow, punctate. 

(PI. XXXIV, Figs. 5-6.) 

United States: Iowa; Illinois. 

190. Spirogyra reflexa Transeau 1915. Ohio Jour. Sci. 16, p. 28. 

Vegetative cells 30-44 a^ x 120-300^1, with plane end walls; i chromatophore, 


by the male gametangia; fertile cells inflated or enlarged and strongly 

reflexed, single or in groups of 2 or 4; zygospores and aplanospores 

ellipsoid, 44-64/j. x 90-150/^-; median spore wall yellow-brown, smooth. 

(PI. XXXIV, Figs. 7-8.) 

United States: Illinois; Michigan; Indiana; Mississippi. 

191. Spirogyra micropunctata Transeau 1915. Ohio Jour. Sci. 

16, p. 27. 

Vegetative cells 30-36/x x 120-300^, with plane end walls; i chro-

SPIROGYRA 201 

matophore, making 3 to 7 turns; conjugation scalar iform; conjugating 

tubes formed almost wholly by the male gametangia; fertile cells in 

groups of 2 or 4, rarely continuous, inflated on the inner side to 50 /x; 

zygospores ellipsoid, 37-42 i^t x 57-100 /a; median spore wall yellow, 

minutely punctate. (PI. XXXIV, Fig. 9.) 

United States: Wisconsin (Prescott Coll.); Illinois; Arkansas (Couch 

Coll.). 

192. Spirogyra corrugata Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 229. 

Vegetative cells (30-) 32-36 (-40)^1 x 1 40-280 ( -400 /x, 

) with plane 

end walls; i to 3 chromatophores, making 2 to 4 turns; conjugation 

scalariform; tubes formed by the male gametangia, usually long and 

broad; fertile cells solitary or in pairs (rarely in series) between vege- 

tative cells, shortened and inflated to 40-60 /a; zygospores ovoid, 42-60 /a 

X 8o-i20jtt; median spore wall of 2 layers, outer thin, coarsely and irreg- 

ularly corrugate; inner yellow or brownish-yellow, finely reticulate. 

(PI. XXXIV, Figs. lo-ii.) 

United States: Illinois; Mississippi; Alabama (Thut Coll.); Tennessee 

(Bold Coll.); Oklahoma (Taft Coll.); West Virginia (Hamblin Coll.). 

China, Szechwan (Jao Coll.). 

193. Spirogyra rugulosa Ivanof 1902. From Bot. Zentralbl. 93, 

p. 383. 1903. Teodoresco. Bot. Zent. Beth. 21, p. 192, 

Figs. 81-87. 1907. 

Vegetative cells 47-57 /^ x 100-350 /j., with plane end walls; i chromatophore, 


by male gametangia; fertile cells shortened, inflated on the conjugating 

side; zygospores ellipsoid or ovoid, 45-52 /x x 102-127;",; median spore 

wall yellow-brown, finely punctate. (PI. XXXIV, Fig. 14.) 

United States: Illinois, Charleston, in an old prairie pond. 

Russia, Bologoe; Rumania, Chita. 

194. Spirogyra wabashensis Tiffany 1927. BoL Gaz. 83, p. 202, 

PI. 9, Fig. I. 

Vegetative cells 40-50 /^ x 120-400 ju^, with plane end walls; 2 to 4 


formed by the male gametangia; fertile cells inflated, single or in groups 

of 2, alternating with vegetative cells; zygospores ellipsoid, 56-76 /x x 

110-150/A; median spore wall yellow, areolate. (PI. XXXIV, Fig. 13.) 

United States: Illinois, Brownsville. 

195. Spirogyra conspicua Gay 1884. Essai d'une monographie 

locale des Conjuguees, p. 91, PI. 4, Fig. 5.


Vegetative cells about 45 /j- x 45-135 m, with plane end walls; 5 chro- 

matophores, making .5 to 1.5 turns; conjugation scalariform; tubes 

formed by the male gamctangia; fertile cells inflated; zygospores ovoid, 

about 55 M X S2/i; median spore wall brown, smooth. 

France, Montpellier. 

196. Spirogyra visenda Transeau 1944. Ohio Jour. Sci. 44, p, 243. 

Vegetative cells 40-45 /x x 130-300^1, with plane end walls; i narrow 

chromatophore, making 4 to 9 turns in the cell; conjugation scalariform, 

with broad tubes formed wholly by the male gametangia; receptive 

gametangia inflated to 60-80 m; zygospores ellipsoid, sometimes ovoid, 

35-65 ju X 92-124 fi; median spore wall yellow, smooth. (PI. XXXIV, 

Fig- 15-) 

United States: Mississippi, Columbus, April 14, 1935. 

Both gametangia are reflexed, and the conjugating pairs are separated 

by much longer vegetative cells. 

197. Spirogyra hungarica Langer 1932. Folia Crypt. 1, p. 1070, 

Figs. 1-8. 

Vegetative cells 53-56 ju. x 1 50-400 m, with plane end walls; i chro- 

matophore, making 6 to 10 turns in the cell; conjugation scalariform; 

tubes obconical, formed wholly by the male gametangia; receptive gam- 

etangia slightly inflated on the conjugating side; zygospores ellipsoid, 

/x 45-53 X 1 20-1 48 /i^; median spore wall smooth, yellow-brown. (PI. 

XXXIV, Fig. 12.) 

Hungary, Sopron. 

SPECIES WITH SEMIREPLICATE END WALLS 

198. Spirogyra narcissiana Transeau 1914. Amer. Jour. Bot. 1, 

p. 290, PI. 25, Figs. 4-6. 

Vegetative cells 12-14/x x 200-400)11, with semireplicate end walls; 

I chromatophore, making 2 to 5 turns; zygospores unknown; sporif- 

erous cells inflated toward the middle up to 25-53^; aplanospores eUip- 

soid to ovoid, 23-501". x 50-120JU; median spore wall yellow, smooth. 

(PI. XXXV, Figs. 1-3.) 

United States: Illinois, Charleston (above dam in small stream north 

of golf links), September, 1912. 

The end walls of the cells of this and the next species are unique and 

under the microscope look like an end view oi a partly open transom. It 

was found in this same stream in September in 2 subsequent years but was 

not found in any other nearby streams, although many collections were 

made and analyzed.

SPIROGYRA 203 

199. Spirogyra undulisepta Randhawa 1938. Proc. Indian Acad. 

Set. 8, p. 352. 

Vegetative cells 13-18 ju. x 96-154 /t with semireplicate end walls; i 

chromatophore, making 3 to 5 turns; conjugation scalariform; tubes 

formed by both gametangia; receptive gametangia inflated in the mid- 

dle up to 30-42 /a; zygospores ellipsoid, 20-30 m x 40-53 m; median spore 

wall yellow-brown, with an undulate outer surface. (PI. XXXV, Fig. 4.) 

India, Fyzabad, Upper Punjab, February 8, 1937. 

SPECIES WITH REPLICATE END WALLS 

200. Spirogyra tenuissima (Hassall) Kiitzing 1849. Species Algarum, 

p. 437. 

Vegetative cells 8-13,a x 40-250^1, with replicate end walls; i chro- 

matophore, making 3 to 6 turns; conjugation lateral and scalariform; 

tubes formed by both cells; fertile cells greatly inflated or enlarged 

toward the middle; zygospores and aplanospores ellipsoid, /tx 25-32 x 

iu.; 40-70 median spore wall yellow, smooth. (PI. XXXV, Figs. 5-6,) 

United States: Abundant in the eastern half in early spring. 

Canada; Europe; Asia; South America; Africa; Australia; New Zealand. 

Highly variable in dimensions within the above limits, also in the 

angles formed by laterally conjugating cells. Several species and varieties 

have been described which are not listed here. If these variants are recognized, 

many more can be separated on equally good grounds. The same 

statement holds for the next species, S. inflata. 

Found hybridizing with S. weberi at Belding, Michigan. Spores in cells 

of S. weberi filaments were ovoid, in the S. tenuissima filaments, ellipsoid. 

201. Spirogyra inflata (Vaucher) Kiitzing 1843. Phycologia 

Generalis, p. 279. 

Vegetative cells 15-20/^ x 45-230 /x, with repHcate end walls; i chromatophore, 

making 2.5 to 6 turns; conjugation lateral and scalariform; 

tubes formed by both gametangia; fertile cells inflated to /x.; 35-48 zygospores 

and aplanospores ellipsoid, 27-36 /x x 50-76 /x; median spore wall 

yellow, smooth. (PI. XXXV, Figs. 7-8.) 

coast. 

United States: From Minnesota and Louisiana eastward to the Atlantic 

Southern and eastern Canada; Europe; Asia; Africa. 

202. Spirogyra cylindrica Czurda 1932. Siisswasserfiora Mittel- 

europa. 9, p. 150. 

Vegetative cells i3-i6ft x I40-350a

204 

ZYGNEMATACEAE 

and scalariform; tubes formed almost wholly by the male gametangia; 

fertile cells inllatcd toward the center to 29-42/^; zygospores ellipsoid, 

22-32M X 50-71 m; median spore wall yellow-brown, smooth. (PI. 

XXXV, Figs. 9-10.) 

Austria; Czechoslovakia; China, Szechwan; South Africa. 

Neither the description nor the figure of S. austriaca Czurda 1932 

clearly separates it from this species. 

203. Spirogyra pseudospreeiana Jao 1935. Sinensia. 6, p. 608. 

Vegetative cells 16-19/^ x 140-210/i, with replicate end walls; i 

chromatophore, making 2.5 to 8 turns in the cell; conjugation scalar- 

iform; tubes formed by the male gametangia; fertile cells inflated 

toward the middle up to 39 i^, especially on the conjugating side; zygo- 

spores ellipsoid, 27-35/A x 45-64/^; median spore wall yellow-brown, 

smooth. (PI. XXXV, Fig. II.) 

China, Szechwan, December, 1933. 

204. Spirogyra pascheriana Czurda 1932. Susswasserflora Mittel- 

europa. 9, p. 150. 

Vegetative cells 18-21 î x 120-170 /x, with replicate end walls; i 

chromatophore; conjugation lateral and scalariform; tubes formed 

mostly by the male gametangia; fertile cells more or less cylindrically 

inflated, up to 60 jj.; zygospores ellipsoid, 45-50^1 x 80-95 ju.; median wall 

yellow-brown, smooth, with distinct suture. (PI. XXXV, Figs. 12-13.) 

United States: Minnesota, Grand Marais (Nichols Coll.), June, 1936. 

Czechoslovakia, Prague. 

205. Spirogyra hopeiensis Jao 1935. Sinensia. 6, p. 608. 

Vegetative cells 26-29 ju, x 154-400 m, with replicate end walls; i 

chromatophore, making 2 to 6 turns in the cell; conjugation scalariform; 

tubes formed by the male gametangia; fertile cells inflated on 

the conjugating side up to 55^1; zygospores ellipsoid, 32-48^11 x 61-96 /x; 

median spore wall smooth, yellow. (PI. XXXV, Fig. 17.) 

China, Hopei and Szechwan; in the former province in June, in the 

latter in December. 

206. Spirogyra farlowii Transeau 19 15. Ohio Jour. Sci. 16, p, 29. 

Phycoth. Bor.-Amer., No. 362. 

Vegetative cells 24-30^1 x 70-400/i., with replicate end walls; i 

chromatophore, making 2.5 to 6 turns; conjugation scalariform and 

lateral; tubes formed by both cells; fertile cells inflated to 39-60 m; zygo- 

spores and aplanospores ellipsoid, ends more or less pointed, 32-45 

48-96/i; median spore wall yellow, smooth. (PI. I, Fig. 3.) 

/i x

SPIROGYRA 205 

United States: Iowa; Michigan; Kentucky; Indiana; Ohio; New Hampshire; 


China, several provinces (Li Coll. and Jao Coll.). 

Named for W. G. Farlow, Harvard University, founder of the Farlow 

Herbarium and Library. 

207. Spirogyra weberi KiJtzing 1843. Phycologia Generalis, p. 279. 

Vegetative cells 19-30 /a x 80-4801"., with replicate end walls; i chromatophore, 

making 3 to 6.5 turns; fertile cells usually slightly enlarged; 

conjugation scalariform; tubes formed by both cells; zygospores ovoid 

to cylindric-ovoid, 21-30 ^ x 30-96 /x; median spore wall yellow, smooth; 

aplanospores similar. (PI. XXXV, Fig. 14.) 

United States: Generally distributed in the eastern half, but not common; 

also in Colorado. 

Widely distributed in Europe, China, Java. 

Found hybridizing with S. tenuissima at Belding, Michigan (Ackley 

Coll.). 

208. Spirogyra semiornata Jao 1935. Sinensia. 6, p. 604, PL 9, 

Figs. 97-98. 

Vegetative cells 27-32 /a x 96-245 /a, with replicate end walls; i chromatophore, 

making 2 to 6 turns in the cell; reproduction usually by 

zygospores, rarely by aplanospores; conjugation lateral and scalariform; 

tubes formed by both gametangia; fertile cells enlarged; zygospores 

ovoid, 35-46/u. X 6i-io6/i; aplanospores subglobose to ovoid, 32-38/1 

X S5-51M; median spore wall yellow-brown, smooth. (PI. XXXV, Figs. 

15-16.) 

China, Szechwan, November to January. 

209. Spirogyra nyctigama Transeau 1938. Amer. Jour. Bot. 25, 

p. 525, Fig. II. 

Vegetative cells 34-38 /a x 72-180/1, with replicate end walls; i chromatophore, 


by both gametangia; receptive gametangia inflated to 65/1; zygospores 

ellipsoid, 47-54/1 x 80-98 /a; median wall yellow-brown, smooth. (PI. 

XXXV, Fig. 18.) 

South Africa, Cape Town (Stephens Coll.). 

210. Spirogyra grevilleana (Hassall) Kiitzing 1849. Species Algarum, 

p. 438. 

Vegetative cells 22-33 i^ ^ 60-325 /i, with replicate end walls ; i chro- 

matophore, in some cells 2, making 4 to 9 turns; conjugation scalar- 

iform and lateral; tubes formed largely by the male gametangia; fertile 

cells fusiform-inflated to 36-43/1; zygospores ovoid, 30-:57/i x 60-90/1; 

median spore wall yellow, smooth. (PI. XXXV, Figs. 19-20.)

2o6 ZYGNEMATACEAE 

United States: Iowa and Missouri eastward to New Jersey. 

Europe; Australia; China. 

This includes the variant described by Czurda (1930) as S. grevilleana 

(Hassall) Czurda. 

211. Spirogyra chuniae Jao 1935. Sinensia. 6, p. 609, PI. 10, 

Fig. 105. 

Vegetative ceils 28-39/1 x 67-130/^, with replicate end walls; i chro- 

matophore, in some cells 2, making 2 to 5.5 turns in the cell; fertile cells 

inflated; reaching a diameter of 8oiu.; conjugation scalariform; tubes 

very short, sometimes formed only by the male gametangia; zygospores 

median spore wall yel- 

ellipsoid with pointed ends, S5~43/^ ^ 70-1 19 a*,; 

low, smooth. (PI. XXXVI, Fig. i.) 

China, Chungking. 

212. Spirog\tia incrassata Czurda 1930. Beih. Bot. Zentralbl. 

47, p. 38, Fig. 10. 

Vegetative cells 26-30 /j. x 200-250 /x, with replicate end walls; (i-) 

2 chromatophores; conjugation lateral and scalariform; tubes formed 

by both cells; fertile cells greatly inflated toward the middle; zygo- 

spores ellipsoid, 42-52 /t x no/'.; median spore wall yellow-brown, irreg- 

ularly punctate, and inwardly channeled. (PI. XXXVI, Figs. 2-4.) 

Germany, Berlin. 

213. Spirogyra rugosa (Transeau) Czurda 1932. Siisswasserflora 

Mitteleuropa. 9, p. 156. Amer. Jour. Bot. 1, p. 291. 19 14. 

Phycoth. Bor.-Amer., No. 456 (as S. tenuissima var. 

rugosa). 

Vegetative cells 10-13/A x 50-210/1, with replicate end walls; i chro- 

matophore, making 2 to 6 turns; conjugation lateral and scalariform; 

tubes formed by both gametangia; fertile cells greatly inflated toward 

the middle; zygospores ellipsoid, 28-32/1 x 55-66 /t; median spore wall 

yellow-brown, minutely scrobiculate. 

United States: Iowa; Illinois; Massachusetts; Rhode Island; New Jersey. 

214. Spirogyra foveolata (Skuja) Czurda 1932. Siisswasserflora 

Mitteleuropa. 9, p. 157. Skuja. Acta Horti Bot. Univ. 

Latviensis. 3, p. 107. 1928. Not S. inftata var. foveolata 

Transeau 1914 (see No. 216). 

Vegetative cells 11-16/A x 90-250/1, with replicate end walls; i chro- 

matophore, making 3 to 10 turns in the cell; conjugation usually lateral, 

sometimes scalariform, with the tubes formed mostly by the male gam- 

etangia; fertile gametangia inflated to 30-45/1 toward the middle; zygo-

SPIROGYRA 207 

spores ellipsoid, 20-31 ju- x 43-92/i.; median spore wall reticulate, yellowbrown. 

(PL XXXVI, Fig. 5.) 

United States: Arkansas (G. C. Couch Coll.); Minnesota near Grand 

Marais (Nichols Coll.). 

Latvia; China, Szechwan (Jao Coll.); India (Randhawa Coll.). 

Perhaps S. tandae Randhawa should be included here, though slighdy 

larger than the type. 

215. SpiROG'i'RA KUUSAMOENSis Him 1895. Actu Soc. pro Fauna et 

Flora Fennica. H, p. 11, Fig. 4. 

Vegetative cells i^-iyi^^ x 90-135^^, with replicate end walls; i chromatophore; 

conjugation lateral and scalariform ; tubes formed by both 

gametangia; fertile cells greatly enlarged toward the middle; zygo- 

spores ellipsoid, 23-33 /x ^ 45~75'^' median spore wall yellow, finely 

punctate. (PI. XXXVI, Fig. 7.) 

Finland; India, Bombay. 

216. Spirogyra discreta Transeau 1934. Ohio Jour. Sci. 34, 

p. 420. Amer. Jour. Bot. 1, p. 291. 1914 (as S. inflata 

var. foveolata) 

Vegetative cells 16-20 p- x 50-220 /.

2o8 

ZYGNEMATACEAE 

chromatophore, making 3 to 8 turns in the cell; reproduction by zygo- 

spores and aplanospores; conjugation lateral and scalariform; tubes 

formed by both gametangia; receptive gametangia more or less cylin- 

drically inflated up to 51 

ju toward the middle; zygospores ellipsoid to 

cylindric-ellipsoid, 34-48/1 x ioo-130/x; median wall smooth, chestnut 

brown; aplanospores similar, ]"• 34-44 x 60-90 /a. (PI. XXXVI, Figs. 

10-13.) 

United States: Several localities near Boston, Massachusetts (Bollard 

Coll.); Illinois, Coles County near Lerna. 

Original collection from Disko, Greenland, August 7, 1871, by T. M. 

Fries. Identity of American material verified by Rosenvinge. Cell walls of 

this species are unusually light-refractive and appear brighter and better 

defined than those of other species of the genus— probably due to a larger 

proportion of cellulose in the walls. 

219. Spirocyra quadrata (Hassall) Petit 1874. Bull. soc. hot. de 

France. 21, p. 41, PI. i, Fig. 2. 

Vegetative cells 24-30 /a x 70-^500 /j., with replicate end walls; 1 chromatophore, 

making 1.5 to 6 turns in the cell; reproduction by zygo- 

spores and aplanospores; conjugation scalariform and lateral; tubes 

formed by both gametangia; receptive gametangia cylindrically inflated 

toward the middle up to 60 m; zygospores ellipsoid to cylindric-ellipsoid, 

33-44/1 X 50-82 /t; median wall smooth, brown; aplanospores similar 

but smaller. (PI. XXXVI, Figs. 14-16.) 

United States: All states from Iowa to Massachusetts. 

Widely distributed in Europe, and in northern and southern China. 

The form with 2 chromatophores in most cells (var. bijasciata Kirchncr 

1878) has been found in Illinois, also in Clark County, Kentucky (Mclnteer 

Coll.). 

220. Spirogyra fritschiana Czurda 1932. Siisswasserflora Mittel- 

europa. 9, p. 156. Trans. Roy. Soc. S. Africa. 18, p. 50, 

Fig. 14A-B (as S. protecta var. inflata). 

Vegetative cells 17-24/1 x 80-260 /t, with replicate end walls; i chromatophore; 


gametangia; fertile cells inflated toward the middle; zygospores eUip- 

soid, 35-40/1 X 55-64 /x; median spore wall brown, coarsely punctate. 

(PI. XXXVI, Figs. 19-20.) 

South Africa, Kimberley. 

221. Spirogyra goetzei Schmidle 1902. Engler's Bat. Jahrb. 30, 

p. 251, PI. 4, Fig. 8. 

Vegetative cells 22-25/1 x 160-^20/1, with replicate end walls; i 

chromatophore, making 4 to 9 turns in the cell; conjugation scalar-

SPIROGYRA 209 

iform; tubes formed by both gametangia; fertile cells shortened and 

enlarged to 32 /t; zygospores ellipsoid, 28-31^0, x 42-62 /a; median spore 

wall punctate to reticulate-punctate, brown. (PI. XXXVI, Fig. 21.) 

water. 

United States: Massachusetts, Wellfleet (BuUard Coll.). 

Africa, Langenburg, Lake Nyassa. 

In the original collection attached and forming long masses in flowing 

222. Spirogyra dentireticulata Jao 1935. Sinensia. 6, p. 611, 

PL 10, Figs. 1 14-15. 

Vegetative cells i8-26;«. x 118-250^1, with rephcate end walls; i 

chromatophore, making 2 to 7 turns; conjugation scalariform; tubes 

formed by both gametangia; zygospores ellipsoid, 29-41/11 x 42-80 /.a; 

median spore wall reticulate, with minute spines at the intersections of 

the network, yellow at maturity. (PI. XXXVI, Figs. 17-18.) 

United States: Tennessee, Rutherford County (Bold Coll.). 

China, Szechwan, December and lanuary. 

223. Spirogyra lambertiana Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 225, PL 21, Fig. 60. 

Vegetative cells i^-'Tpix x 120-300 /a, with replicate end walls; i 

chromatophore, making 3.5 to 7 turns in the cell; conjugation lateral 

and scalariform; tubes formed by both gametangia; fertile cells fusi- 

form, inflated to 58-65 (-78) ju,; zygospores ellipsoid, 34-43 /a x 72-90 /a; 

median spore wall of 2 layers; outer, thin, yellow, wrinkled; inner, 

thick, yellow, or yellow-brown, reticulate. (PL XXXVII, Fig. i.) 

United States: Maine; Massachusetts. 

India, Fyzabad, February, 1938. 


224. Spirogyra microgranulata Jao 1935. Sinensia. 6, p. 612, 

PL 10, Figs. 1 12-13. 

Vegetative cells 16-19^'' x 154-420/A, with replicate end walls; i 

chromatophore, making 4.5 to 8 turns in the cell, conjugation scalar- 

iform; tubes formed by both gametangia; receptive gametangia en- 

larged; zygospores ovoid, 24-36 /a x /J', 5 1-77 with a double colorless 

outer wall, of which the inner layer is wrinkled; median wall granulate 

to verrucose, yellow-brown at maturity. (PL XXXVII, Figs. 2-3.) 


225. Spirogyra laxistrata Jao 1935. Sinensia. 6, p. 611, PL 10, 

Fig. III. 

Vegetative cells 18-20/A x 112-147/A, with replicate end walls; i 

chromatophore, making 2.5 to 4 turns; conjugation scalariform; tubes


formed by the male gametangia; fertile cells cylindrically inflated toward 

the middle; zygospores ovoid, 35-3^/^- x 45-48/1; median spore 

wall double, of which the outer layer is thick, smooth, and yellow; the 

inner, coarsely areolate, yellow-brown at maturity. (PI. XXXVII, 

Fig- 1 3-) 

China, Szechwan, December 27, 1933. 


226. Spirogyra spreeiana Rabcnhorst 1863. Die Algen Sachsens, 

No. 988. 

Vegetative cells 18-24/1 x 140-600/1, with replicate end walls; i 

chromatophore, making 1.5 to 4 turns; conjugation scalariform and 

lateral; tubes formed mostly by the male gametangia; fertile cells not 

shortened, enlarged and inflated toward the middle to 30-42/1; zygo- 

spores and aplanospores ellipsoid, 30-36/1 x 55-100/'.; median spore wall 

yellow, smooth. (PL XXXVII, Figs. 4-6.) 

United States: Texas; Iowa; Michigan; Tennessee; eastward to Massachusetts; 

Washington. 

Europe, Germany to Finland and Rumania; South Africa. 

Original collection by Th. Spree near Boekhorst, Holland, in 1S60. 

Czurda gives diameter of vegetative cells as i6-i8/

SPIROGYRA 211 

tubes formed by both gametangia; sterile cells more or less cylindrically 

inflated up to /x; 45 fertile cells enlarged; zygospores ellipsoid, 25-35 /j- ^ 

48-86jU.; median spore wall smooth, yellow at maturity. (PI. XXXVII, 

Fig- 9-) 

China, Szechwan, November to January, 1933-34. 

230. Spirogyra croasdaleae Blum 1943. Amer. Jour. Bot. 30, 

p. 783, Figs. 6-8. 

Vegetative cells 17-25 /x x 120-300 /«., with replicate end walls; i 

chromatophore, making 4 to 8 turns in the cell; conjugation scalar- 

iform; tubes formed by the male gametangia; fertile cells much inflated 

on the conjugating side; zygospores eUipsoid, 26-33 /x x 46-62 /x; median 

wall yellow, smooth. (PI. XXXVII, Fig. 14.) 

United States: Massachusetts, Naushon Island, July 20, 1942. 

231. Spirogyra lamellosa Jao 1935. Sinensia. 6, p. 605, PI. 9, 

Fig. 99. 

Vegetative cells iu. 29-32 x 188-280 /a, with replicate end walls; i 


iform; tubes narrow and long (32-96 /".), formed by both gametangia; 

fertile cells cylindric or enlarged; zygospores ellipsoid to cylindric- 

ellipsoid, 32-42 /a x 80-102 /a; outer wall colorless, lamellate, 3-4/"- in 

thickness; median wall smooth, yellow at maturity, (PL XXXVII, 

Fig. 16.) 

264. 


The conjugating tubes are similar to those of Numbers 243, 245, and 

232. Spirogyra laxa Kiitzing 1849. Species Algarum, p. 438. 

Tabulae phycologicae. 5, PL 30, Fig. 5. 

Vegetative cells 30-36 /a x 120-320 as with replicate end walls; i 

chromatophore, making 3 to 5 turns; conjugation lateral and scalar- 

iform; tubes formed by both gametangia; fertile cells cylindric; zygospores 

ellipsoid, with more or less pointed ends, 30-33 /x x 60-82/^1; median 

spore wall yellow, smooth. 

United States: Iowa; Michigan; Indiana. 

Nova Scotia (Hughes Coll.); Europe. 

233. Spirogyra tjibodensis Faber 1912. Ann. ]ard. Bot. Buiten- 

zorg. 26, p. 265. 

Vegetative cells 45-50 /x x 80-130 /i, with repHcate end walls; i chromatophore, 

making about 4 turns; reproduction by zygospores and 

aplanospores; conjugation scalariform; tubes formed by both gam-


ctangia; fertile cells cylindric; zygospores ellipsoid, 32-35 /i x 37-42 m; 

median wall brown; aplanospores, 30-34/1 x 35-40 /n, similar. 

Java, Tjibodas. 

234. Spir(x;yra articulata Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 226, Pi. 22, Figs. 67-69. 

Vegetative cells 24-28 /i x 360-600/1, with replicate end walls; i 

chromatophore, making 3 to 8 turns in the cell; zygospores unknown; 

reproducing by ellipsoid aplanospores, 36-40 /i x 60-88//; median spore 

wall yellow, smooth; sporangia cylindric, enlarged or slightly inflated, 

sometimes straight, often bowed or bent toward the middle. (PI. 

XXXVII, Fig. 10.) 

United States: Mississippi, Columbus; Indiana, Vigo County (Ben 

Smith Coll.). 

235. Spirogyra latviensis (Skuja) Czurda 1932. Siisswasserfiora 

Mitteleuropa. 9, p. 147. Skuja. Acta Horti Bot. Univ. 

Latviensis. 3, p. 109. 1928 (as S. protecta forma). Also 

described as S. petitiana Transeau 1934. 

Vegetative cells 20-25 /j. ^ 100-250/1, with replicate end walls; i 

chromatophore, making 3 to 5.5 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells inflated to 30-40/1; 

zygospores ovoid to cylindric-ovoid, 29-39 /t x 75-1 15 /a; outer hyaline 

spore wall of 2 layers, of which the outer is thin; the inner, thick, ver- 

rucose, with short, pointed elevations; median wall smooth, yellowbrown. 

United States: Minnesota; New York (Blum Coll.); Massachusetts 

(Bullard Coll.). 

Latvia. 

236. Spirogyra venusta Jao 1935. Sinensia. 6, p. 614, PI. 10, Figs. 

118-19. 

Vegetative cells 25-27/A x 175-350/i, with replicate end walls; i 


iform; tubes formed by both gametangia; sterile cells inflated at the 

ends; fertile cells cylindric or enlarged; zygospores cylindric-ellipsoid, 

26-32/i X 67-84/1; outer spore wall of 2 layers, of which the inner is 

colorless, strongly scrobiculate; median spore wall smooth and yellow. 

(PI. XXXVII, Figs. 17-18.) 

China, Szechwan, December 27, 1934. 

237. Spirogyra protecta Wood 1872. Smithson. Contribu. Knowledge. 

19, p. 165, PI. 14, Fig. 3. Cleve. Nova Acta Reg. 

Soc. Sci. Upsali. Ser. 3, 6, p. 26. 1868 (as S. calospora

SPIROGYRA 213 

forma gracilior). Czurda. Susswasserflora Mitteleuropa. 

9, p. 147 

(as S. calospora Cleve). 

Vegetative cells 28-34 /a ^ 1 fi, 20-425 with replicate end walls; i, 

rarely 2, chromatophores, making 2 to 6 turns; reproduction by zygo- 

spores and aplanospores; conjugation scalariform ; tubes formed by 

both gametangia; receptive gametangia cylindric or enlarged; zygo- 

spores ovoid, 30-38 /x X 66-90 iit; outer spore wall of 2 layers, of which 

the inner is thick, scrobiculate; median spore wall yellow, smooth; 

aplanospores similar but smaller. (PI. XXXVII, Fig. 19.) 

United States: Common throughout the eastern half. 

Europe, recorded from France to Finland and the Ukraine. 

Bessey in 1884 reported conjugation between S. protecta and S. majuscula 

in both directions. Spore forms corresponded to those of the female 

filament. Under the name S. calospora Cleve described 2 different forms; 

the first, and larger, had i to 3 chromatophores and a yellow, scrobiculate 

median spore wall. Wood published an accurate description in 1872. 

238. Spirogyra cleveana Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 226. Jao. Sinensia. 6, p. 614, PI. 11, Fig. 120, 

Vegetative cells 34-40 /x x û., 140-465 with rephcate end walls; i, 

rarely 2, chromatophores, making 3 to 6 turns in the cell; conjugation 

scalariform; tubes formed by both gametangia; sterile cells often greatly 

inflated; fertile cells cyhndric or enlarged; zygospores ovoid to cylin- 

dric-ovoid, 34-50 m x 70-125/*; outer spore wall hyaline, of 2 layers, 

of which the inner is thick and coarsely scrobiculate; median spore wall 

smooth, yellow. (PL XXXVIII, Fig. i.) 

United States: Common in the eastern half. 

China, Szechwan; probably includes the larger forms of S. calospora 

(Cleve) in Europe. 

239. Spirogyra denticulata Transeau 1934. Trans. Amer. Micros. 

Soc. 53, p. 226. 

Vegetative cells 42-56^ x 160-400 /x, with replicate end walls; i, 

rarely 2, chromatophores, making 3 to 6 turns; conjugation scalariform; 

tubes formed by both gametangia; fertile cells cylindric or enlarged; 

sterile cells sometimes inflated; zygospores ovoid, 45-60 ju. x 76-130 ^c; 

outer hyaUne spore wall of 2 layers; the outer thin, smooth; the inner, 

thick, scrobiculate; median spore wall yellow, smooth. (PI. XXXVII, 

Fig- 15-) 

United States: Mississippi; Illinois; Indiana; Ohio; Massachusetts. 

240. Spirogyra areolata Lagerheim 1883. Ofvers. Kgl. Vet.-AI{ad. 

Forhandl. Stockholm. 40 (2), p. 56, PI. i, Figs. 18-20. 

Vegetative cells 30-36 /x x 120-600 /x, with replicate end walls; i or

214 

ZYGNEMATACEAE 

2 chromatophores, making 3 to 9 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated up to 67 /x; zygospores 

ovoid to ovoid-globose, 40-57 /^ x 60-10^/1; outer spore wall of 2 layers, 

of which the inner is hyaline, scrobiculate; median spore wall yellowbrown, 

smooth. (PI. XXXVIII, Fig. 2.) 

United States: Illinois; Ohio; Maine. 

Latvia; Germany. 

241. Spirogyra tolosana Comere 1899. Bull. soc. hot. de ¥ranee. 

46, p. 168, PL 3, Figs. 1-3. 

Vegetative cells 28-30 ju. x 225-300 /a, with replicate end walls; 2 

chromatophores, making 3.5 to 4 turns; conjugation lateral; fertile cells 

cylindric or enlarged and shortened; zygospores cylindric-ovoid, with 

ends more or less truncate when filling the gametangium, 26-29 m x 

95-108 m; median wall yellow-brown, smooth. (PI. XXXVIII, Fig. 3.) 

United States: Indiana, Clay and Vigo Counties (Ben Smith Coll.). 

France, Toulouse. 

Approaches S. hassallii, differs in having smaller ovoid spores. 

242. Spirogyra hassallii (Jenner) Petit 1880. Les Spirogyres 

des environs de Paris, p. 13, PL 2, Figs. 6-8. 

Vegetative cells 26-33 ft ^ 100-250 /x, with replicate end walls; 2 

chromatophores, making 1.5 to 5 turns; conjugation lateral and scalar- 

iform; fertile cells fusiform, inflated to 50^1; tubes formed by both 

gametangia; zygospores ellipsoid, )«. 39-48 x 58-136 jn; median spore wall 

yellow, smooth. (PL XXXVIII, Fig. 4.) 

United States: Colorado; North Dakota; Iowa; Illinois; to the New 

England states. 

Widely distributed in Europe and eastern Asia. 

243. Spirogyra hartigii Kiitzing 1855. Tabulae phycologicae. 5, 

P- 33- 

Vegetative cells about 45 /x x 500-675/'., with replicate end walls; 2 

chromatophores, making 2 turns; conjugation lateral and scalariform; 

tubes formed by both gametangia, longer than usual; and in lateral 

conjugation the tube primordia arise 4 to 5/u. from the end walls; recep- 

tive gametangia enlarged or slightly inflated at the middle; zygospores 

ovoid, jti 45-50 x 80-105 /x; median spore wall smooth. (PI. XXXVIII, 

Figs. 5-

SPIROGYRA 215 

244. Spirogyra gratiana Transeau 1938, Amer. Jour. BoL 25, 

p. 528, Figs. 12-13. 

Vegetative cells 28-33 /x x 144-400 /a, with replicate end walls; usually 

3 chromatophores (rarely in some cells 2 or ; 4) conjugation lateral and 

scalariform ; tubes formed by both gametangia; receptive gametangia 

cylindric or enlarged; zygospores ellipsoid, Ai 35-47 x 108-223 ju.; all walls 

smooth; median wall yellow; aplanospores infrequent, smaller, 38-40^0. 

X47-72A^. (PL XXXVIII, Figs. 8-^.) 

Coll.). 

United States: Minnesota, Grand Marais, June 17, 10^6 (Grace Nichols 

The filaments are remarkable in that they are almost perfecdy straight 

during and after conjugation. 

245. Spirogyra proavita Langer 1913. Boi. KdzlemenyeJ^. 12, 

p. 166. 

Vegetative cells 37-40 jU, x fi, 330-560 with replicate end walls; 2-3 

chromatophores, making i to 3.5 turns in the cell; conjugation lateral; 

tubes arising from primordia several microns away from the end wall, 

thus forming a distinct tube outside the filament; fertile cells cylindric; 

zygospores ovoid, 38-40 /x x 82-86 ju.; median spore wall smooth, brown- 

ish-yellow when mature. (PI. XXXVIII, Fig. 7.) 

Hungary. 

This species resembles Number 243, S. hartigii, in important partic- 

ulars and perhaps is a somewhat smaller variant; differs from Number 264, 

S. crassispina, in having ovoid spores. 

246. Spirogyra transeauiana Jao 1935. Sinensia. 6, p. 610, PI. 10, 

Fig. 107. 

Vegetative cells 42-61 /i. x 160-304;^, with repHcate end walls; 2 to 3 


formed by both gametangia; fertile cells cylindric or slightly enlarged 

on the conjugating side; zygospores ellipsoid with rounded ends, 

41-58 /x x 96-183/U.; median spore wall yellow, smooth. (PI. XXXVIII, 

Fig. 10.) 


247. Spirogyra rectangularis Transeau 1914. Amer. Jour. BoL 

1, p. 291, PI. 25, Figs. 9-11. 

Vegetative cells 35-40 /i x 1 50-320 /x, with repHcate end walls; 2 to 4 

chromatophores, making 2 to 5 turns; conjugation lateral and scalar- 

iform; tubes formed by both gametangia; fertile cells cylindrically in- 

flated to 48-70^; zygospores ovoid to cylindric-ovoid, 45-65 /x x 75-120 /j.; 

median spore wall yellow-brown, smooth. (PI. XXXVIII, Figs. 11-12.)

2i6 ZYGNEMATACEAE 

United States: Illinois, Charleston and Lerna. 

Austria, Lunz. 

248. Spirogyra insignis (Hassall) Kiitzing 1849. Species Algarum, 

p. 438. 

Vegetative cells 39-42 m x 150-590/1, with replicate end walls; 2 to 4 

(usually 3) chromatophores, making .5 to 1.5 turns; conjugation scalar- 

iform and lateral; tubes formed by both gametangia; fertile cells 

shortened and inflated; zygospores ellipsoid, 40-48 /^ x 60-128 m; median 

spore wall yellow-brown, smooth. (PI. XLI, Fig. 17.) 

United States: Iowa; Illinois. 

Widely reported from Europe; China, Nanking and Szechwan. 

249. Spirogyra fallax (Hansgirg) Wille 1900. Nyt Magaz. /. 

Naturw. 38, p. 16. Hansgirg. Hedivigia. 27, p. 253. 

1888 (as S. insignis var. fallax). 

Vegetative cells 36-45 ft x 80-165 as with replicate end walls; 3 to 4 

chromatophores, straight, or making .5 to 1.5 turns in the cell; conjuga- 

tion scalariform; tubes formed by both cells; fertile cells inflated to 

48-75 m; zygospores ellipsoid, 45-60/1 x 75-1 20 /x; median spore wall 

brown, smooth. (PI. XXXVIII, Fig. 13.) 

United States: Massachusetts. 

Czechoslovakia. See note under S. inconstans, Number 252. 

250. Spirogyra wangi Li 1933. Ohio Jour. Sci. 33, p. 153, PL i, 

Figs. 7-8. 

Vegetative cells 30-32/^1 x 150-350 as with replicate end walls; 2 to 3 

chromatophores, making 1.5 to 4.5 turns; conjugation scalariform; tubes 

formed by both gametangia; fertile cells inflated toward the middle, up 

to 72 ,u; zygospores ellipsoid, 60-64 /x ^ 112-124/^; median spore wall 

smooth, yellow. (PI. XXXVIII, Figs. 14-15.) 

China, Hangchow, 1930. 

251. Spirogyra acanthophora (Skuja) Czurda 1932. Siisstvasser- 

fiora Mitteleuropa. 9, p. 160. Skuja. Acta Horti Bot. Univ. 

Latviensis. 3, p. 114. 1928 (as S. ivillei var. acanthophora). 

Vegetative cells 30-38 /.a x 75-350/1, with replicate end walls; 3 to 4 

chromatophores, making .5 to 1.5 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; receptive gametangia inflated 

to 50-70 /J.; zygospores ellipsoid, 42-60 /x x 80-1 40 /x; median wall irreg- 

ularly spinose-reticulate, yellow-brcjwn. (Pi. XXXVIIl, Figs. 16-17.) 

Latvia, Kemeri. 

This species differs from the next (No. 252) in the more prominent 

spines on the reticulum of the median spore wall, and in the decreased 

reflexing of conjugating gametangia.

SPIROGYRA 217 

252. Spirogyra inconstans Collins 1912. Tufts College Studies. 

3, p. 73; Phycoth. Bor.-Amer., No. 1768. Wittrock and 

Nordstedt Algae Exsiccatae, No. 958. 1889. 

Vegetative cells 28-40 /a x /-i, 70-350 with replicate end walls; (2-) 

to 4 chromatophores, nearly straight, or making .5 to 1.5 turns in the 

cell; conjugation scalar iform or rarely lateral; tubes formed by both 

gametangia; at the time of tube formation both gametangia become 

reflexed and usually the conjugation between the same pair of filaments 

is limited to single, or to 2 adjoining pairs of cells; cross conjugation 

is not infrequent; receptive gametangia shortened and inflated up 

to 50-75 m; zygospores ellipsoid to broadly ellipsoid, 45-70 jU, x 75-140 /x; 

median wall reticulate-aculeate, brown. (PI. XXXVIII, Figs. 18-20.) 

United States: Illinois; Michigan; Indiana; Ohio; Massachusetts; Wash- 

ington (Bodenberg Coll.). 

Europe, from Sweden to Rumania. 

At the time of tube formation an outer pectic ring is formed at the 

junction, and at maturity there is usually an outer and an inner tube wall. 

The history of the specific name of this species is a striking example of 

a scientific "Comedy of Errors." In 1889 Nordstedt described and distrib- 

uted specimens of this alga, as S. insignis (Hassall) Kiitzing forma. In 1899 

Wille attached the name S. jallax to it, based on a variety described by 

Hansgirg as S. insignis var. jallax which has smooth-walled spores, alleging 

that Hansgirg had overlooked the ornamented median spore wall. In 1907 

Teodoresco found an alga similar to Nordstedt's forma, and named it 

S. insignis var. Nordstedtii. In 19 12 Collins described the same alga as 

S. inconstans. In 1913 Borge perpetuated Wille's error. In 1915 Transeau 

called attention to the discrepancy between Hansgirg's figure and descrip- 

tion and those of Wille, but, following Borge's key, decided in favor of 

S. jallax. In 191 8 Collins changed the name in his key to S. jallax. In 1928 

Skuja renamed the species S. willei. Czurda in 1932 relegated Collins' 

S. inconstans to the discard, and used the name S. willei. Collins, however, 

first described the alga as a species and his specific name is therefore valid. 

253. Spirogyra borysthenica Kasanofsky & Smirnoff 1913. 

Oesterr. Bot. Zeitschr. 63, p. 137, PL 3. 

Vegetative cells 30-40 /x x 1 80-450 /x, with replicate end walls; 2 to 4 

chromatophores, straight, or making up to 2.5 turns in the cell; con- 

jugation scalariform; tubes formed by both gametangia; fertile cells 

inflated up to 70 /a; zygospores ellipsoid, 52-62^1 x 110-160/J.; median 

spore wall with spinelike or mammaeform papillae, yellow-brown. 

(PI. XXXIX, Figs. 1-3.) 

United States: Michigan (Ackley Coll.); Iowa (Tiffany Coll.). 

U.S.S.R., Bukovina.

2i8 

ZYGNEMATACEAE 

254. Spirogyra nawashini Kasanofsky 1913. Berichte deutsch. 

hot. Gesells. 31, p. 55, PI. 3. 

Vegetative cells 27-41 /x x 170-325/i, with replicate end walls; 2 

(rarely i) chromatophores, with .5 to 1.5 turns; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells fusiform, inflated 

to 50-55 m; zygospores ellipsoid to cylindric-ellipsoid, 30-49^1 x 45-1 00 /j-; 

median spore wall reticulate, yellow-brown. 

Coll.). 

United States: Indiana (Ben Smith Coll.). 

Ukraine, Kiev; China, Nanking (Li Coll.); South Africa (Stephens 

255. Spirogyra tetrapla Transeau 1938. Amer. ]our. Bot. 25, 

p. 528, Fig. 6. 

Vegetative cells /x, 30-40 x 100-250 /n, with replicate end walls; i or 2 

chromatophores, making 2 to 8 turns in the cell; conjugation scalar- 

iform; tubes formed by both gametangia; fertile cells inflated, up to 

66m; zygospores ellipsoid, 48-58 /j. x 68-88 /a; median wall of 2 layers, of 

which the outer is thin and irregularly corrugate; the inner, finely 

reticulate, yellow. (PI. XXXIX, Fig. 4.) 

United States: Illinois; Indiana; Ohio; Mississippi, 

256. Spirogyra reticulata Nordstedt 1880. Bot. Notiser 1880. 

p. 118. Wittrock and Nordstedt Algae Exsiccatae, No. 362. 

Vegetative cells 28-42 /li x 72-460 /j., usually with replicate end walls; 

I to 3 (usually 2) chromatophores, making 2 to 4 turns; conjugation 

scalariform and lateral; tubes formed by both gametangia; fertile cells 

enlarged or inflated toward the middle to 48-60 /t; zygospores mostly 

ovoid, 45-61 

/A X 80-120 /i.; median spore wall yellow-brown, of 2 layers, 

of which the outer is thin and wrinkled; the inner reticulate. (PI. 

XXXIX, Fig. 5.) 

United States: Iowa; Oklahoma; Mississippi; eastward to Maine and 

south to Florida. 

Brazil; Europe; China; India. 

This description is amended as to the median spore wall. This wall is 

double in both specimens from Brazil upon which Nordstedl's description 

is based and is likewise present in the American, European, and Chinese 

specimens that I have examined. 

257. Spirogyra regularis (Cedercreutz) Krieger 1944. Rabin- 

horst's Kryptogamenflora. 13, p. 464. Acta Soc. pro 

Fauna et Flora Fennica. 55 (2), p. 3. 1924. 

Vegetative cells 21^32 /x x 110-380 m, with replicate end walls; 2 

chromatophores, making 4 to 6 turns in the cell; conjugation scalar-

SPIROGYRA 219 

iform; tubes formed by both gametangia; fertile cells enlarged or in- 

flated; zygospores ovoid, 39-45 /x x fi, 60-90 yellow-brown; median wall 

reticulate. (PI. XXXVII, Figs. 11-12.) 

Finland. 

The description does not state whether the median wall is single or 

double. It is included here as a species closely related to the preceding and 

characterized by smaller spores and a definite number of chromatophores. 

258. Spirogyra crassivallicularis Jao 1935. Trans. Amer. Micros. 

Soc. 54, p. 2, PL I, Fig. 4. 

Vegetative cells 54-58 ft x 168-420 ft; end walls replicate; chromatophores 

usually 4, rarely 3, making 1.5 to 3.5 turns in the cell; conjuga- 

tion scalariform; tubes formed by both gametangia; fertile cells en- 

larged, or inflated up to 80 /x; zygospores ovoid, 52-71 /x x 90-144 /x; 

median wall of 2 layers, of which the outer is thin, wrinkled, and yel- 

low; the inner thick, yellow-brown and reticulate with thick irreg- 

ularly crenulate ridges. (PI. XXXIX, Fig. 6.) 


259. Spirogyra granulata Jao 1935. Sinensia. 6, p. 613, PI. 11, 

Figs. 1 16-17. 

Vegetative cells i". 32-35 x 147-280 /ti, with replicate end walls; 2 

chromatophores, making 2.5 to 6 turns in the cell; conjugation lateral; 

tubes formed by both gametangia; receptive gametangia enlarged toward 

the middle; zygospores ovoid to cylindric-ovoid, 45-55/^^ x 93-131 /x; 

median wall double, of which the outer layer is thin and irregularly 

wrinkled; the inner, granulate and slightly wrinkled, yellowish-brown. 

(PL XXXIX, Figs. 7-8.) 


See also Number 261, .S. pseudogranulata Ley. 

260. Spirogyra quinquelaminata Jao 1935. Sinensia. 6, p. 615, 

PL II, Figs. 121-22. 

Vegetative cells 41-45^1 x 154-280 /x, with replicate end walls; 2 

chromatophores, making 2 to 4 turns in the cell; reproduction by zygo- 

spores and aplanospores; conjugation scalariform; tubes formed by both 

gametangia; fertile cells enlarged toward the middle; sterile cells some- 

times inflated up to 70 /x; zygospores ovoid, 51-55 M x 83-144^1, with 5 

layers in the spore wall; outer spore wall of 2 layers, of which the outer 

is thin and colorless; the inner up to ju. 3.5 in thickness and distinctly 

lamellate; median spore wall yellow-brown, also of 2 layers, of which 

the outer is thin and somewhat wrinkled; the inner, coarsely and irreg- 

ularly reticulate, the ridges being crenulate to dentate; aplanospores


subglobose, 41-48/i x 41-67/Li, with similarly marked walls. (PI. 

XXXIX, Figs. lo-ii.) 

China, Szechwan, November 11, 1933. 

SPECIES DESCRIPTIONS NOT IN PROPER SEQUENCE 

261. Spirogyra pseudogranulata Ley 1944. Si?jensia. 15, p. 99. 

Vegetative cells 36-40 /i x 152-378/1, end walls replicate; chromato- 

phores 2; conjugation lateral; tubes formed by both gametangia; recep- 

tive gametangia enlarged or inflated; zygospores ovoid, 46-68 /x x 

100-140/M; median spore wall of 2 layers; the outer thick, irregularly 

corrugate; the inner minutely reticulate, yellow-brown. (PI. XXXIX, 

Fig- 9-) 

China, Tong-Kau, Kwangtung, March 10, 1942. 

Should be compared with Number 259, S. granulata Jao. 

262. Spirogyra jaoi Ley 1944. Sine?isia. 15, p. 99. 

Vegetative cells 19-22 /.i x 64-216^^, end walls replicate; i chromatophore; 

conjugation scalariform; tubes formed by both gametangia, 

receptive gametangia inflated; zygospores ovoid, 28-40 /x x 54-90 m; 

median spore walls of 2 layers; the outer thin and wrinkled; the inner 

smooth, yellow at maturity. (PI. XXXIX, Fig. 12.) 

China, Tong-Kau, Kwangtung, February 17, 1942. 

Belongs near Number 225, S. laxistrata Jao, from which it differs in the 

characteristics of the median spore wall, and in the formation of the con- 

jugating tubes. 

263. Spirogyra chekiangensis Jao 1939. Smeiisia. 10, p. 152. 

Vegetative cells 25-28 ju. x 100-200 /a, with plane end walls; i chromatophore, 

making 1-2 turns in the cell; conjugation scalariform; tubes 

formed by both gametangia; receptive gametangia enlarged; zygospores 

ovoid, 45-48/^ x 85-88 ;u; median spore wall of 2 layers, of which 

the outer is thin, irregularly wrinkled and yellow; the inner coarsely 

and irregularly reticulate, yellow-brown at maturity. (PI. XXXIX, 

Fig- 13-) 

China, Wenchow. 

Compare with Number 45, S. obovata jao, which has somewhat similar 

vegetative cells but much larger zygospores, and single-layered median 

spore wall. 

264. Spirogyra crassispina Jao 1939. Sinensia. 10, p. 153. 

Vegetative cells 30-35 /a x 326-351 /u, with rephcate end walls; chromatophores 

2, making i to 3.5 turns in the cell; conjugation lateral and 

scalariform; tubes formed by both cells; receptive gametangia enlarged;

SPIROGYRA 221 

zygospores ellipsoid or sometimes cylindric-ellipsoid, 42-50 /x x 80-1 37 /a; 

median spore wall of 2 layers, of which the outer is thin, yellow, and 

wrinkled; the inner coarsely dentate or tuberculate, yellow-brown at 

maturity. (PL XXXIX, Figs. 14-16.) 

China, Haimen, May 6, 1937. 

Compare with Number 243 and Number 245. 

265. Spirogyra peipingensis }ao 1939. Sinensia. 10, p. 155. 

Vegetative cells 113-125/^ x (82-) 105-332 /x, with plane end walls; 

chromatophores 5 or 6, making .5 to 2.5 turns in the cell; conjugation 

scalariform; tubes formed by both cells; receptive gametangia cylindric 

and shortened; zygospores lenticular, 100-128 a^ x 82-100 m; median spore 

wall smooth, yellow-brown at maturity. (PL XXXIX, Fig. 20.) 

China, Peiping, December, 1935. 

Belongs near Number 159, S. submaxima Transeau. 

266. Spirogyra sphaerocarpa Jao 1939. Sinensia. 10, p. 156. 

Vegetative cells 32-40 û, x /a, 87-459 with plane end walls; chromatophores 

4 or 5, making .5 to i turn in the cell; conjugation scalariform; 

tubes formed by both gametangia; receptive gametangia inflated toward 

the middle up to 75-87 fi; zygospores lenticular, 62-75 /a x /a; 37-57 median 

spore wall densely punctate, yellow-brown at maturity. (PL 

XXXIX, Figs. 17-18.) 

China, Wenchow, May 13, 1937. 

Belongs near Number 161, S. bellis (Hassall) Cleve. 

267. Spirogyra subpellucida Jao 1939. Sinensia. 10, p. 157, 

Vegetative cells 40-45 /a x 62-225 a


269. Spirogyra iNDicA Kficgcr 1944. Rabenhorst's Kryptogamen- 

flora. 13, p. 317. 

Vegetative cells 36-42^ x iio-152/i, with plane end walls and i 

chromatophore; conjugating tubes formed by both gametangia; conjugation 

mostly lateral, less frequently scalariform; receptive gametangia 

cylindric; zygospores ovoid, 33-^S/x x 40-62 /a; median spore wall thick, 

smooth, and brown. (PI. XLI, Figs. 20-21.) 

India, Central Provinces; South America, south Chile. 

270. Spirogyra czurdae Misra 1937. Proc. Indian Acad. Sci. 5, 

p. 115, Fig. 3. 

Vegetative cells 26-28 m x 52-78 /a, with plane end walls and i chromatophore; 


receptive gametangia shortened and enlarged; zygospores globose, 

^^-54/^ in diameter; median spore wall very thick, brown, and scrobic- 

ulate; pits 3-4 /j. in diameter. (PI. XLI, Figs. lo-ii.) 

India, Kashmir. 

271. Spirogyra sibirica Skvortzof 1927. ]oHr. Bot. 65, p. 252, 

Fig. I. 

Vegetative cells about 17/1 broad, with plane end walls and i chromatophore; 

conjugation scalariform; tubes formed by male cells; recep- 

tive gametangia inflated slightly on the inner side; many sterile cells 

bullate; zygospores ellipsoid, 20 /a x 32-40 /a; median spore wall yellow, 

scrobiculate. (PI. XLI, Figs. 8-9.) 

Russia, Western Altai Mountains, Zaisan district. 

272. Spirogyra atasiana Czurda 1939. Arch. f. Hydrobiol. Suppl. 

Bd. 16, p. 417, PI. I, Fig. 3. 

Vegetative cells 44-48 /x x 92-161 m, with plane end walls and i chromatophore; 

conjugation scalariform; tubes formed apparently by the 

male gametangia; receptive gametangia cylindric; zygospores ovoid, 

41-45/ji X 50-90 /t; median spore wall thick, yellow-brown, outer surface 

granulose. 

Sumatra, Danau di Atas. 

273. Spirogyra pseudoreticulata Kriegcr 1944. Rabenhorst's 

Kryptogamenflora. 13, p. 400. 

Vegetative cells 20-25 /x x 75-170 ^n, with plane end walls and 2 chromatophores; 


cells; receptive gametangia enlarged; zygospores ellipsoid, 30-33 m x 

64-68 A^; median spore wall brown, with rather fine, irregular, reticulate 

ridges. (PI. XLI, Figs. 13-15.) 

Brazil, Sao Paulo.

SPIROGYRA 223 

274. Spirogyra verrucosa (Rao) Krieger 1944. Rabenhorst's 

Kryptogamenflom. 13, p. 398. Jour. Indian Bot. Soc. 17, 

p. 358, Fig. 3. 

Vegetative cells 108-126 /j. x 144-190 m, with plane end walls and 

4-8 chromatophores; conjugation scalariform; tubes formed by both 

cells; receptive gametangia cylindric; zygospores ellipsoid, 89-100 /j. x 

1 16-165 /x; median wall thick, brown, minutely verrucose, and with 

coarse meshed reticulate ridges. (Pi. XLI, Fig. 19.) 

India, Central Provinces. 

275. Spirogyra marchica Krieger 1944. Rabenhorst's Kryptogamenflora. 

13, p. 459. 

Vegetative cells 29-32^0. x 150-250 /x, with replicate end walls and 2 

chromatophores; conjugation lateral and scalariform; tubes formed by 

both cells; receptive gametangia inflated on both sides; zygospores 

ovoid to ellipsoid with rounded ends, 46-53 M x 86-170/1; median spore 

wall brown, coarsely verrucose. (PI. XLI, Figs. 22-23.) 

Germany, Brandenburg. 

List of the Species of SPIROGYRA with Number 

acanthophora (Skuja) Czurda 1932 251 

aequinoctialis G. S. West 1907 109 

affinis (Hassall) Petit 1880 23 

ajricana (Fritsch) Czurda 1932 134 

amplectens Skuja 1937 217 

angolensis Welwitsch 1897 76 

anomala Rao 1937 139 

aphanosculpta Skuja 1937 58 

aplanospora Randhawa 1938 38 

areolata Lagerheim 1883 240 

arta Jao 1935 

228 

articulata Transeau 1934 234 

asiatica Czurda 1931 46 

atasiana Czurda 1939 272 

australensis Mobius 1895 63 

azygospora Singh 1938 

166 

baileyi Schmidle 1896 103 

bellis (Hassall) Cleve 1868 161 

bicalyptrata Czurda 1930 13 

bichromatophora (Randhawa) Transeau 1944 105 

biformis Jao 1935 72 

borgeana Transeau 1915 19 

borysthenica Kasanofsky & Smirnoff 1913 253

224 

ZYGNEMATACEAE 

braziliensis (Nordstedt) Transeau 1915 123 

brunnea Czurda 1932 131 

buchetii Petit 1913 104 

bullata ]ao 1935 

calcarea Transeau 1934 

20 

castanacea G. C. Couch 1944 

120 

catenaejonnis (Hassall) Kiitzing 1849 24 

chel{iangensis Jao 1939 

263 

chenii Jao 1935 

182 

c/iiingf(ingensis Jao 1935 

117 

chuniae Jao 1935 

211 

circumlineata Transeau 1914 14 

cleveana Transeau 1934 238 

colligata Hodgetts 1920 157 

collinsii (Lewis) Printz 1927 183 

Columbiana Czurda 1932 

communis (Hassall) Kiitzing 1849 

75 

i 

condensata (Vaucher) Kiitzing 1843 

6 

conspicua Gay 1884 195 

corrugata Transeau 1934 

192 

crassa Kiitzing 1843 167 

crassispina Jao 1939 264 

crassiuscula (W, & N.) Transeau 1934 

crassivallicularis Jao 1935 

crassoidea Transeau 1937 175 

croasdaleae Blum 1943 230 

cylindrica Czurda 1932 

202 

cylindrospora W. & G. S. West 1897 146 

czurdae Misra 1937 

daedalea Lagerheim 1888 61 

daedaleoides Czurda 1932 

62 

decimina (Miiller) Kiitzing 1843 96 

denticulata Transeau 1934 239 

dentireticulata Jao 1935 

222 

dictyospora Jao 1935 

diluta Wood 1869 148 

discoidea Transeau 19:^4 152 

discreta Transeau 1934 216 

distcnta Transeau 1934 92 

dubia Kiitzing 1855 107 

echinata Tiffany 1924 149 

echinospora Blum 194:5 147 

ellipsospora Transeau 1914 

88 

21 

172 

258 

270 

in

SPIROGYRA 225 

elliptica Jao 1935 83 

emilianensis Bonhomme 1858 90 

esthonica (Skuja) Czurda 1932 187 

exilis W. & G. S. West 1907 91 

jallax (Hansgirg) Wille 1900 249 

farlowii Transeau 1915 

206 

fennica Cedercreutz 1924 

16 

flavescens (Hassall) Kiitzing 1849 26 

fluviatilis Hilse 1863 133 

formosa (Transeau) Czurda 1932 164 

fossa Jao 1935 

113 

foveolata (Skuja) Czurda 1932 214 

jragilis Jao 1935 9 

jranJ{liniana Tiffany 1934 155 

fritschiana Czurda 1932 220 

juellebornei Schmidle 1902 67 

gallica Petit 1880 

33 

ghosei Singh 1938 144 

gibberosa Jao 1935 

18 

glabra Czurda 1932 

160 

goetzei Schmidle 1902 221 

gracilis (Hassall) Kiitzing 1849 

8 

granulata Jao 1935 259 

gratiana Transeau 1938 244 

grevilleana (Hassall) Kiitzing 1849 210 

groenlandica Rosenvinge 1883 218 

grossii Schmidle 1901 136 

hartigii Kiitzing 1855 243 

hassallii ( Jenner) Petit 1880 242 

hatillensis Transeau 1936 87 

heeriana Nageli 1849 171 

hoehnei Borge 1925 53 

hollandiae Taft 1947 69 

hopeiensis Jao 1935 

205 

hunanensis Jao 1940 151 

hungarica Langer 1932 197 

hyalina Cleve 1868 73 

hydrodictya Transeau 1915 177 

hymerae Britton & Smith 1942 

81 

inconstans Collins 1912 252 

incrassata Czurda 1930 

212 

indica Krieger 1944 

269


inflata (Vaucher) Kiitzing 1843 201 

insignis (Hassall) Kiitzing 1849 248 

intorta Jao 1935 

2 

irregularis Nageli 1849 66 

jaoensis Randhawa 1938 102 

jaoi Ley 1944 

jassiensis (Teodoresco) Czurda 1932 165 

jatobae Transeau 1938 169 

juergensii Kiitzing 1845 3 

jugalis (Fl. Dan.) Kiitzing 1845 99 

l{affirita Transeau 1934 59 

lûusatnoensis Him 1895 215 

labyrinthica Transeau 1934 64 

lacustris Czurda 1932 34 

lagerheimii Wittrock 1889 47 

lambertiana Transeau 1934 

223 

lamellosa Jao 1935 

latviensis (Skuja) Czurda 1932 235 

laxa Kiitzing 1849 232 

laxistrata Jao 1935 

lenticularis Transeau 1938 174 

liana Transeau 1934 

180 

longata (Vaucher) Kiitzing 1843 30 

lushanensis Li 1938 186 

luteospora Czurda 1932 42 

lutetiana Petit 1879 37 

macrospora (Rao) Krieger 1944 

268 

majuscula Kiitzing 1849 

158 

malmeana Hirn 1896 141 

manoramae Randhawa 1938 

168 

maravillosa Transeau 1938 65 

marchica Krieger 1944 

margaritata WoUny 1877 

275 

100 

maxima (Hassall) Wittrock 1882 170 

megaspora (Lagerheim) Transeau 1934 173 

miamiana Taft 1944 

115 

microgranidata Jao 1935 

224 

micropunctata Transeau 1915 

microspora Jao 19^5 

mienningensis Li 1940 

minor (Schmidle) Transeau 1944 

minntifossa Jao 1935 51 

262 

231 

225 

191 

68 

121 

130

SPIROGYRA 227 

mirabilis (Hassall) Kutzing 1849 29 

moebii Transeau 1934 

162 

narcissiana Transeau 1914 

198 

natchita Transeau 1934 

112 

nawashini Kasanofsky 1913 254 

neglecta (Hassall) Kutzing 1849 95 

nitida (Dillwyn) Link 1833 80 

notabilis Taft 1944 

novae-angliae Transeau 1915 

nyctigama Transeau 1938 

oblata Jao 1936 163 

obovata Jao 1935 45 

occidentalis (Transeau) Czurda 1932 

4^ 

oltmannsii Huber-Pestalozzi 1930 

3^ 

orientalis W. & G. S. West 1907 

118 

ovigera Montague 1850 137 

paludosa Czurda 1932 

28 

papulata Jao 1935 

5^ 

paraguayensis Borge 1903 

128 

parvispora Wood 1869 78 

paruula (Transeau) Czurda 1932 

17 

pascheriana Czurda 1932 

204 

peipingensis Jao 1939 

265 

pellucida (Hassall) Kutzing 1849 156 

perforans Transeau 1934 49 

plena (W. & G. S. West) Czurda 1932 97 

polymorpha Kirchner 1878 39 

polytaeniata Strasburger 1888 

loi 

porangabae Transeau 1938 5° 

porticalis (Miiller) Cleve 1868 35 

pratensis Transeau 1914 

22 

prescottii (Prescott) Transeau 1944 

181 

proavita Langer 1913 245 

propria Transeau 1915 

protecta Wood 1872 237 

pseiidograntdata Ley 1944 

261 

pseudoneglecta Czurda 1932 74 

pseudoreticulata Krieger 1944 

273 

pseudospreeiana Jao 1935 

203 

pseudovarians Czurda 1930 

11 

pulchrifigurata Jao 1935 

124 

punctata Cleve 1868 

184 

punctictdata Jao 1935 

135 

138 

209 

142 

108


punctijormis Transeau 1914 189 

punctulata Jao 1956 145 

qttadrata (Hassall) Petit 1874 219 

quadrilaminata Jao 1935 

126 

quinqiielatninata Jao 19^5, 260 

rectangularis Transeau 1914 247 

rectispira Merriman 1922 176 

reflexa Transeau 1915 190 

regularis (Cedcrcrcutz )Krieger 1944 257 

reinhardii Chmielevski 1903 150 

reticulata Nordstedt 18S0 256 

rhizobrachialis Jao 1935 

rhizoides Randhawa 1938 

rhizopus Jao 1936 

riviilaris (Hassall) Rabenhorst 1868 71 

robtista (Nygaard) Czurda 1932 54 

rugosa (Transeau) Czurda 1932 215 

rugulosa Ivanof 1902 193 

sahnii Randhawa 1938 36 

schmidtii W. & G. S. West 1902 114 

scripta Nygaard 1932 1:52 

scrobiculata (Stockmayer) Czurda 1932 57 

semiornata Jao 1935 

208 

setijormis (Roth) Kiitzing 1845 

82 

shantungensis Li 1936 

122 

siamensis Transeau 1951 94 

sibirica Skvortzof 1927 271 

silvicola Britton 1 94 3 5 

sinensis Li 1933 1 54 

singtilaris Nordstedt 1880 4 

sirogonioides Hughes 194^ 185 

sl{ujac Randhawa 1938 52 

smithii Transeau 1934 

116 

sphaerocarpa Jao 1939 

266 

sphaerospora Hirn 1895 15:5 

splendida G. S. West 1914 89 

spreciana Rabenhorst 1865 226 

subcylindrospora Jao 1 935 

submarina (Collins) Transeau 191 5 70 

submaxima Transeau 1914 159 

subpapulata Jao 1955 55 

subpellucida Jao 1939 267 

subrcticulata Fritsch 1921 129 

127 

106 

no 

119

SPIROGYRA 229 

siibsalina Cedercreutz 1924 25 

subsalsa Kutzing 1845 27 

suecica Transeau 1934 

sulcata Blum 1943 43 

suomiana Transeau 1934 

188 

supervarians Transeau 1934 

szechwanensis Jao 1935 

taftiana Transeau 1944 4^ 

taylorii Jao 1935 i79 

tenuissima (Hassall) Kutzing 1849 200 

teodoresci Transeau 1934 

tetrapla Transeau 1938 255 

texensis Taft 1944 

178 

tjibodensis Faber 1912 233 

tolosana Comere 1899 241 

torta Blum 1943 125 

trachycarpa Skuja 1932 143 

transeauiana Jao 1935 246 

triplicata (Collins) Transeau 1944 93 

tsingtaoensis Li 1936 227 

tuberculata Lagerheim 1896 

60 

tumida Jao 1935 

229 

turfosa Gay 1884 79 

itndidisepta Randhawa 1938 199 

varians (Hassall) Kutzing 1849 12 

varijormis Transeau 1938 7 

velata Nordstedt 1873 40 

venusta Jao 1935 

236 

verrucosa (Rao) Krieger 1944 274 

verruculosa Jao 1936 

140 

visenda Transeau 1944 

wabashensis Tiffany 1927 194 

wangi Li 1933 250 

weberi Kutzing 1843 

207 

welwitschii W. & G. S. West 1897 77 

westii Transeau 1934 44 

wollnyi de Toni 1889 84 

wrightiana Transeau 1938 85 

yunnanensis Li 1939 

32 

15 

98 

10 

196 

86

CHAPTER FOURTEEN 

THE GENUS SIROGONIUM KtJTZING 1843 

The vegetative cells of the species belonging to this genus 

resemble those of certain species of Spirogyra with plane end walls 

and several narrow chromatophores. The cell wall, however, 

differs in the absence of an appreciable external pectose layer. The 

average length of the cell is two to four times the diameter, though 

exceptional cells may attain lengths of five to seven diameters. 

The described species have from two to ten chromatophores, 

which are either straight or only slightly curved, and comparatively 

narrow. 

Conjugation occurs directly between gametangia, without the 

formation of conjugating tubes. Apparently the gametangia on 

coming in contact adhere, and the walls in contact change to 

pectose and pectic acid. At the edges of the contact disc, a ring 

of pectose develops outside the walls. At the same time the walls 

of both gametangia grow, and after bending enlarge to a characteristic 

form best described by the figures on Plate XL. 

The development of the gametangia takes places only from 

certain vegetative cells scattered singly or in pairs along the filaments. 

Usually the progametangia divide into two unequal gametangia—one 

short and one long—and food substances accumu- 

late in them. There may be two divisions resulting in a larger 

gametangium between two short cells. De Bary stated that the 

first type of division resulted in female and the latter in male 

gametes; he called the short cells "sterile." However, the development 

of gametangia is highly variable in some collections. Appar- 

ently progametangia may conjugate without division. Any of the 

short cells may become male gametangia, and division into three 

cells before conjugation is far less frequent than division into two 

unequal cells. As a result of the flexing of the gametangia at the 

beginning of a conjugation, successive conjugations in a particular 

filament are each with a different filament. Conjugated filaments 

thus form a tangled net. 

231

232 

ZYGNEMATACEAE 

Usually the mature spores are ellipsoid, although ovoid spores 

occur in most collections. The median wall may be smooth or 

variously ornamented, and the color varies from pale yellow to 

brown and black. 

Twelve species are here described. 

Key to the Species of SIROGONIUM 

I. Zygospores with a smooth median wall 2 

I. Zygospores with a variously ornamented median wall 4 

I. Zygospore lenticular 12. S. p/iacosponim 

2. Diameter vegetative cells usually less 

than /J. 36 1. S. tenuius 

2. Diameter vegetative cells usually between 36 and 56/^ 3 

2. Diameter vegetative cells about 56- 

66 /i 4. S. fiuridamnn 

3. Diameter zygospores about 10-15 m 

larger than vegetative cells 2. ^S. sticticiitn 

3. Diameter zygospores 20-30 /a larger 

than vegetative cells 3. 6\ megasporum 

4. Median wall of zygospore single 5 

4. Median wall of zygospore double... 10. S./iiti 

5. Median spore wall "punctate" 6. 5. ceylaniciim 

5. Median spore wall finely corrugate and 

granulose 5. »S. pseiidofloridanum 

5. Median spore wall brown to black, verrucose 6 

5. Median spore wall reticulate g. 5. illinoicnse 

5. Median spore wall scrobiculate \\. S. indicum 

6, Diameter vegetative cells 65^2 /i. ... 7. ^S". ventersicujii 

6. Diameter vegetative cells 70-90/i.... S. S.melanospunijyj 

Descriptions or Species 

I. SiROCONiUM TENUIUS (Nordstcdt) Transeau 1934. Ohio Jour. 

Sci. 34, p. 420. Nordstedt. Bot. Notiser 1882. p. 47 (as 

Spirogyra stictica var. tetiuior). 

Vegetative cells 32-36^1 x 50-135 ;n; 2 to 5 chromatophores, nearly 

straight; conjugation direct between shortened and more or less rcflexed 

gametangia, separated by vegetative cells; receptive gamctangia intlatcd 

to 60/i; zygospores ellipsoid varying to ovoid, 47-50 /t x 60-S8/1; median 

spore wall yellow, smooth. 

United States: Oklahoma; Texas; Arkansas; Florida. 

Argentina, Cordoba; Brazil, Mate (irosso; Burma.

SIROGONIUM 233 

Fig. G.—Conjugation through end wall of male gametangial filament in Sirogonium 

sticticum. Specimen and drawing from C. E. Taft. 

2. Sirogonium sticticum (Engl. Bet.) Kiitzing 1843. Phyco- 

logia Getieralis, p. 278. 

Vegetative cells 38-56/4 x 80-300 /x; chromatophores 3-6, nearly 

straight, or making .5 turn; conjugation direct between usually shortened 

and more or less reflexed gametangia; receptive gametangia in- 

flated to 72iM; spores ellipsoid, sometimes more or less ovoid, ju. 41-67 x 

68-127/4; median spore wall smooth, yellow. (PI. XL, Figs. 1-4.) 

Widely distributed in Europe, Asia, Africa, South America, Australia, 

and in the United States, and southern Canada. The numbers of chroma- 

tophores, cell diameters, and spore dimensions are highly variable. 

3. Sirogonium megasporum (Jao) Transeau 1944. Ohio Jour. 

Sci. 44, p. 244. Sinensia. 6, p. 645, PI. 12 (as S. sticticum 

var. megasporum). 1935. 

Vegetative cells 48-55 /( x 90-385 /x; chromatophores 3 to 4, sometimes 

2, straight, or making .5 turn in the cell; conjugation direct, gam- 

etangia shortened, reflexed, and more or less inflated on the inner side; 

receptive gametangia inflated up to 100 /x; zygospores ellipsoid to ovoid, 

70-85/1. X 100-122 /I ; median spore wall smooth, yellowish-brown at 

maturity. (PL XL, Fig. 5.) 

United States: Texas, Bastrop, April 17, 1938 (Taft Coll.). 

China, Szechwan; South America, Ecuador, near Quito (Prescott Coll.). 

4. Sirogonium floridanum (Transeau) G. M. Smith 1933. 

Freshwater Algae of the United States, p. 557. Transeau. 

Ohio Jour. Sci. 16, p. 30. 1915. 

Vegetative cells 56-66/1. x 120-335/1; 4-5 chromatophores, nearly 

straight, or making a half turn; conjugation direct; gametangia short-

234 

ZYGNEMATACEAE 

cncd and rcilexcd; receptive gametangia inflated up to 135/^; zygospores 

ellipsoid, 75-105^1. x 95-1 35 Ml median spore wall yellow and 

smooth. 

United States: Florida. Original collection by John Donnell Smith, 

March, 1878, in southwest part of the peninsula; again collected by L. H. 

Tiffany in the same region in April, 1933. 

South Africa, Cape Town (E. L. Stephens Coll.). 

5. SiROGONiuM PSEUDOFLORIDANUM (Prcscott) Tfanscau 1944. 

Ohio Jour. Set. 44, p. 243. Farlowia. 1, pp. 360-61, Fig. i. 

1944. 

Vegetative cells 51-60 jn x 150-275/^, each with 4 to 5 chromatophores; 

straight, or making up to 1.5 turns in the cell; receptive gam- 

etangia somewhat inflated; zygospores eUipsoid, 63-70JU. x 100-120^; 

median wall brown, finely corrugate and granulate. (PI. XL, Fig. 6.) 

United States: Wisconsin, Vilas County. 

6. SiROGONiuM CEYLANicuM Wittrock 1889. WittFock and Nord- 


Vegetative cells 69-75 /a ^ 1 40-300 /x; 7 chromatophores, nearly 

straight; conjugation direct between reflexed gametangia; receptive 

gametangia inflated, 120-165/^ x 135-300/1; zygospores ellipsoid, 100- 

iiOju. X 135-195/i.; median spore wall thick, yellow-brown with minute 

shallow depressions that have no distinct edges but are easily seen 

when viewed edgewise. 

Ceylon. 

7. SiROGONiuM vENTERSicuM Transcau 1934. Trans. Amer. 

Micros. Soc. 53, p, 229. 

Vegetative cells 65-72 /j. x i i 0-250 /x; 5 to 8 chromatophores, straight, 

or making i turn; conjugation direct; receptive gametangia inflated to 

ioo-140/i; spores mostly ellipsoid, rarely somewhat ovoid, 80-90/x x 

133-152/4; median spore wall brown, densely and irregularly verrucose. 

(PI. XL, Fig. 7.) 

South Africa, Transvaal, Ventersdorp. 

8. SiROGONiuM MELANospoRUM (Randhawa) Transeau 1944. 

Ohio Jour. Sci. 44, p. 243. Proc. Indiaji Acad. Sci. 8, 

p. 364. 1938. 

Vegetative cells 70-90/1 x 140-260 /x, each with 6 to 9 nearly 

straight chromatophores; conjugation direct; receptive gametangia in- 

flated up to 120-166 /x; zygospores usually ellipsoid, go-iio/i x 140-160 /t; 

median spore wall brown to black, verrucose. (Pi. XL, Fig. 8.)

Coll.). 

SIROGONIUM 235 

United States: Mississippi, Greenville, August, 1945 (L. A. Whitford 

India, Fyzabad, Upper Punjab, September-October. 

Differs from S. ventersicum in being larger in all dimensions, and in 

having a black rather than a brown median spore wall. 

9. SiROGONiuM iLLiNoiENSE (Transcau) G. M. Smith 1933. Freshwater 

Algae of the United States, p. 557. Transeau. Amer. 

Jour. Bot, 1, p. 296, Figs. 1-3. 19 14. 

Vegetative cells 65-85 /x x 100-310 ft; 6 to 9 chromatophores, nearly 

straight or making up to i turn in the cell; both gametangia more or 

less reflexed, the receptive one inflated; zygospores ellipsoid, 85-1 15 ji^ x 

140-190^1; median wall yellow with scattered protuberances connected 

by a more or less prominent reticulum. (PI. XL, Figs. 12-13.) 

United States: Originally collected at Lerna, Illinois, from a single 

prairie pond now destroyed; not found elsewhere in central Illinois during 

7 years of collecting. Recently collected in eastern Oklahoma by C. E. Taft. 

10. SiROGONiuM Hui (Li) Transcau 1944. Ohio four. Sci. 44, 

p. 244. Bull. Fan Mem. Inst. Biol., Botany. 8, p. 91 (as 

Spirogyra hui Li). 1938. 

Vegetative cells 82-108 /^ x 140-256 ft, with plane end walls; 5 

to 10 

chromatophores; receptive gametangia inflated to 150ft; zygospores 

ellipsoid to ovoid, 88-ii5ft x 133-192 ft; outer spore wall thin, colorless; 

median wall of 2 layers; outer layer thin, irregularly wrinkled; inner 

layer yellow, verrucose; the inner wall thin and transparent. Akinetes 

86-92 ft X 64-96 ft are common. (PI. XL, Figs. lo-ii.) 

China, Kiangsi. 

This is the largest species in the genus and the only one with a double 

median spore wall. Described as a Spirogyra, but the figure is sufficient evidence 

that it should be classified as a Sirogonium. The description has been 

amended slightly after examination of the type material. 

11. Sirogonium indicum Singh 1938. ]our. Indian Bot. Soc. 17, 

p. 384, Fig. 6B. 

Vegetative cells 65-80 ft in diameter, with approximately 7 chromatophores 

which are nearly straight; conjugation scalariform between 

reflexed gametangia; receptive gametangia greatly inflated; zygospores 

ellipsoid, y^-ôiJ. x i35-i65ft; median spore wall thick, yellow, and 

scrobiculate. (PI. XL, Fig, 9.) 

India. 

12. Sirogonium phacosporum Skuja 1949. Nova Acta Soc. Sci. 

Upsali. Ser. 3, 14, p. 103, PI. 22, Figs. 1-5.

236 

ZYGNEMATACEAE 

Figs. H to K. Sirogonitim phacospoitim vegetative cells, conjugation pattern, and 

2 views of spore with markings. After Skiija. 

Vegetative cells 54-60 /

INDEX

INDEX 

Roman numerals refer to plates, arable numbers immediately following refer to figures in plates, and 

roman capital letters refer to illustrations in the body of the text. Page numbers are in boldface t^fpe. 

acadiana (Mougeotia), 100 

acanthophora (Spirog^ra), XXXVIII, 

16-17; 216 

ackleyana (Debarya), XII, 20-21; 77 

adnata (Mougeotia), XIII, 15-17; 91 

adpectinatum (Zygncma), III, 4; 25 

aequinoctialis (Spirogyra), XXVIII, 

10; 178 

affinis (Spirogyra), 157 

africana (Mougeotia), XIV, 11-12; 93 

africana (Spirogyra), 185 

americana (Mougeotia), XVIII, 1-3; 105 

americana (Zygnemopsis), VIII, 18-21: 53 

amplectens (Spirogyra), XXXVI, 8-9; 207 

angolensis (Mougeotia), XVI, 16; 100 

angolensis (Spirogyra), 170 

angusta (Mougeotia), XIII, i; 89 

anomala (Spirogyra), 186 

aphanosculpta (Spirogyra), XXV, 8; 166 

aplanospora (Spirogyra), XXIII, 17-18; 161 

areolata (Mougeotia), XV, 9-1 1; 96 

areolata (Spirogyra), XXXVIII, 2; 213 

areolatum (Zygnema), III, 5; 25 

arta (Spirogyra), XXXVII, 8; 210 

articulata (Spirogyra), XXXVII, 10; 212 

asiatica (Spirogyra), XXIV, 6; 163 

aspera (Mougeotia), 111 

atasiana (Spirogyra), 222 

atrocoeruleum (Zygnema), 38 

atubulosa (Mougeotia), XVII, 13-14; 103 

australensis (Spirogyra), XLI, 12; 167 

austriaca (Mougeotia), XIX, 11-12; 110 

azurcum (Zygnema), VI, 15; 39 

azygospora (Spirogyra), XLI, 16; 193 

baileyi (Spirogyra), XXVIII, 7; 177 

bellis (Spirog>Ta), XXXI, 17-18; 191 

bicalpytrata (Spirogyra), XXII, 2; 154 

bichromatophora (Spirogyra), XXVIII, 

6; 177 

biformis (Spirogyra), XXVI, 9-10; 169 

bohemicum (Zygnema), VI, 3; 36 

boodlei (Mougeotia), XVIII, 23-25; 108 

borgeana (Spirogyra), XXII, 8; XXIII, 

16; 155 

borinquinae (Pleurodiscus), XII, 12-15; 71 

borysthenica (Spirogvra), XXXIX, 

1-3; 217 

borzae (Zygnema), VII, 4; 42 

239 

braziliensis (Spirogyra), 182 

brunnea (Spirogyra), XXX, 1-2; 184 

buchetii (Spirogyra), 177 

bullata (Spirogyra), XXII, 13; 156 

caelestis (Mougeotia), XV, i; 95 

caimani (Mougeotia), XVII, 18; 105 

calcarea (Mougeotia), XIII, 10-12; 90 

calcarea (Spirogyra), 156 

calospora (Mougeotiopsis), XII, 16-17; 74 

calosporum (Zygnema), V, 4; 33 

capense (Zygogonium), XI, 9-1 1; 67 

capucina (Mougeotia), XVIII, 26-31; 107 

carinatum (Zygnema), IV, 11; 30 

carinthiacum (Zygncma), VI, 16; 39 

carterae (Zygnema), 23 

castanacea (Spirogyra), 181 

catenaeformis (Spirogyra), XXII, 12; 

XXIV, 16; 157 

catenatum (Zygnema), 40 

ceylanicum (Sirogonium), 234 

chalybeospermum (Zygnema), VI, 8; 38 

chekiangensis (Spirogyra), XXXIX, 

13; 220 

chenii (Spirogyra), XXXIII, 14; 198 

cherokeana (Mougeotia), XVII, 23; 105 

chlamydata (Mougeotia), XIII, 19; 113 

chungii (Zygnema), II, 12; 24 

chungkingensis (Spirogyra), XXIX, 

1-2; 180 

chuniae (Spirogyra), XXXVI, i; 206 

circumcarinatum (Zygnema), IV, 8-9; 30 

circumlincata (Spirogyra), XXII, 3; 154 

cleveana (Spirogyra), XXXVIII, i; 213 

coeruleum (Zygnema), IV, 3-4; 28 

colligata (Spirogyra), XXXI, 11-13; 190 

collinsianum (Zygnema), VI, 11-13; 38 

collinsii (Spirogyra), XXXIII, 12-13; '98 

Columbiana (Spirogyra), XXVI, 15; 170 

Columbiana (Zygnemopsis), VIII, 

15-17; 53 

communis (Spirogyra), XXI, i; 150 

condensata (Spirogyra), XXI, 11; 152 

conspicua (Spirogyra), 201 

conspicuum (Zygnema), II, 8; 23 

corniculata (Mougeotia), XVIII, 4-5; 105 

corrugata (Spirogyra), XXXIV, lo-ii; 201 

costata (Debarya), XII, 22-23; 76 

cotopaxicnsis (Mougeotia), XIII, 20; 114

240 

crassa (Mougcotia), 95 

crassa (Spirogyra), XXXII, 6; F; 193 

crassispina (Spirogvra), XXXIX, 

14-16: 220 

crassiuscula (Spirogyra), 195 

crassiusculum (Zygncma), VI, 6-7; 37 

crassivallicularis (Spirogyra), XXXIX, 

6; 219 

crassoidca (Spirogyra), XXXIII, i; 195 

cratcrophora (Mougcotia), XVIII, 

11-14; 106 

croasdalcac (Spirogyra), XXXVII, 14; 211 

cruciatum (Zygncma), I, 9; 36 

cyanea (Mougcotia), XVII, 15-17; 102 

cyancum (Zygncma), VI, 9-10; 38 

cyanosporuni (Zygncma), 27 

cylindrica (Spirogyra), XXXV, 9-10; 203 

cylindricum (Zygncma), VII, 9; 41 

cylindrospcrmuin (Zygncma), IV, 16; 31 

cylindrospora (Spirogyra), 188 

cylindrosporum (Zygncma), VI, 2; 36 

czurdae (Spirogyra), XLI, lo-ii; 222 

czurdae (Zygncma), III, 13-14; 27 

daedalea (Spirogyra), XXV, 9-10; 166 

daedaleoides (Spirogyra), XXV, 

13-15; 167 

daytonae (Mougcotia), XVI, 5; 98 

Debarya, 75-78 

species of 

-ticscriptions, 76-78 

-illustrations, XII, 18-30 

-key, 76 

dccimina (Spirogyra), XXVII, 16; 175 

dccussata (Zygncmopsis), IX, 12-15; 57 

decussatum (Zygncma), II, 7; 23 

dclicata (Mougcotia), XVIII, 17; 107 

dcnticulata (Spirogyra), XXXVII, 15; 213 

dcntircticulata (Spirogyra), XXXVI, 

17-18; 209 

dcprcssa (Mougcotia), XVII, i; 101 

desmidioidcs (Zygnemopsis), VIII, 

12-14; 53 

dictyospora (Spirogyra), XXVIII, 14; 179 

diluta (Spirogyra), XXX, 19-20; 188 

discoidca (Spirogyra), XXXI, 7; 189 

discrcta (Spirogyra), XXXVI, 6: 207 

disjuncta (Mougcotia), XVII, 7-S; 102 

distcnta (Spirogyra), 174 

drouetii (Mougcotia), I, lo; 92 

dubia (Spirogyra), XXVIII, 8; 178 

cchinata (Spirogyra), XXXI, 1-2; 188 

cchinospora (Spirogyra), XXX, 17-18; 188 

cicgantula (Mougcotia), XVIII, 21-22; 108 

cliipsoidca (Mougcotia), XIII, 14; 91 

cllipsoidcum (Zygncma), A; 44 

cilipsospora (Spirogyra), XXVIl, 11; 173 

clliptica (Spirogyra), XXVII, 6; 172 

cmiliancn.sis (Spirogyra), XXVII, 12; 174 

ZYGNEMATACEAE 

Entransia, 121 

species of 

-description, 121 

-illustration, XX, 15 

cricetorum (Zygogonium), X, 10-16; 65 

esthonica (Spirogyra), XXXIV, 2-3; 200 

cxcommunc (Zygncma), VII, 3: 40 

cxcomprcssum (Zygncma), VI, 14; 39 

cxcrassum (Zygncma), III, 7; 26 

exilis (Spirogyra), XXVII, 13; 174 

extenuc (Zygncma), IV, 12; 31 

cxuviclliforme (Zygogonium), XII, 6-8; 68 

fallax (Spirogyra), XXXVIII. 13; 216 

fanicum (Zygncma), V, 13-14; 35 

farlovvii (Spirogyra), I, 3; 204 

fennica (Spirogyra), XXII, 4; 154 

fcrtilis (Zygncmopsis), IX, 17; 57 

fimbriata (Entransia), XX, 15; 121 

flavcscens (Spirogyra), XXIII, i; 157 

flavum (Zygncma), V, 3; 33 

floridana (Mougcotia), 104 

floridana (Zygncmopsis), VIII, 8-9; 52 

floridanum (Sirogonium), 233 

fluviatilis (Spirogyra), XXX, 5; 184 

formosa (Spirogyra), XXXII, 4: 192 

fossa (Spirogyra), XXVIII, 15-16: 179 

foveolata (Spirogyra), XXXVI, 5: 206 

fragilis (Mougcotia), 111 

fragiJis (Spirogyra), XXI, 6: 152 

frankliniana (Spirogyra), 190 

frigidum (Zygncma), I, 6; 41 

fritschiana (Spirogyra), XXXVI, 

19-20; 208 

fucllebornci (Spirogyra), XXVI, 4; 168 

gallica (Spirogyra), XXIII, 8; 159 

gangcticum (Zygncma), 43 

gedcanum (Zygncma), III, 11-12; 27 

gelatinosa (Mougcotia), XVI, 17; 101 

genuflcxa (Mougcotia), XI\', 16-17: 94 

gcrmanicum (Zygncma), V, 8-9; 35 

ghosci (Spirogyra), XXV, 12; 187 

gibberosa (Spirogyra), XXII, lo-ii; 155 

giganteum (Zygncma), III, 9-10; 27 

glabra (Spirogyra), XXXI, 16; 191 

globosum (Zygncma), III, 2-3; 25 

giobulispora (Mougcotia), X\', 15-16; 98 

glyptospcrma (Debarya), XII, 18-19; 76 

goctzci (Sjiirogyra), XXX\'I, 21; 208 

gorakhporcnsc (Zygncma). 29 

godandica (Mougcotia), XV, 14: 97 

gracilis (Spirogyra), XXI, 5; 152 

gracilis (Zygncmopsis), VIII, 6-7; 52 

gracillima (Mougcotia), XIX, 1-2; 108 

granulata (Spirogyra), XXXIX, 7-8; 219 

granulosa (Mougcotia), XVIII, 18-20; 107 

gratiana (Spirogyra), XXXVIII, 8-9; 215 

grcvillcana (Spirogyra), XXXV, 19-20; 205 

grocnianilicn fSpirogyra), XXXVI, 

10-13; 207

grossii (Spirogyra), XXX, 6; 185 

Hallasia, 61 

species of 


-illustrations, X, 1-9 

handelii (Mougeotia), XVI, 6; 99 

hansgirgii (Zygogonium), XI, 4-6; 66 

hardyi (Debarya), XII, 29-30; 17 

hartigii (Spirogyra), XXXVIII, 5-6; 214 

hassallii (Spirogyra), XXXVIII, 4; 214 

hatillensis (Spirogyra), XXVII, 10; 173 

hausmannii (Zygnema), IV, 17-18; 32 

heeriana (Spirogyra), XXXII, 12-13; 194 

heterosporum (Temnogametum), XX, 

10; 118 

heydrichii (Zygogonium), XI, 13-15; 67 

himalayense (Zygnema), II, 4; 23 

hirnii (Mougeotia), XIV, 13; 94 

hodgettsii (Zygnemopsis), IX, 22; 58 

hoehnei (Spirogyra), XXIV, 13; 164 

hollandiae (Spirogyra), XXVI, 6-7; 168 

hopeiensis (Spirogyra), XXXV, 17; 204 

hui (Sirogonium), XL, lo-ii; 235 

hunanensis (Spirogyra), XXXI, 6; 189 

hungarica (Spirogyra), XXXIV, 12; 202 

hyalina (Spirogyra), XXVI, 11-12; 170 

hydrodictya (Spirogyra), XXXIII, 2-4; 196 

hymerae (Spirogyra), XXVII, 3; 171 

hypnosporum (Zygnema), VII, 12; 42 

illinoiense (Sirogonium), XL, 12-13; 235 

inconspicuum (Zygnema), VI, 5; 37 

inconstans (Spirogyra), XXXVIII, 

18-20; 217 

incrassata (Spirogyra), XXXVI, 2-4; 206 

indica (Spirogyra), XLI, 20-21; 222 

indica (Zygnemopsis), VIII, 26-27; 54 

indicum (Sirogonium), XL, 9; 235 

indicum (Zygogonium), 68 

inflata (Spirogyra), XXXV, 7-8; 203 

insigne (Zygnema), V, 10-12; 35 

insignis (Spirogyra), XLI, 17; 216 

insignisporum (Zygnema), 34 

intorta (Spirogyra), XXI, 2; 150 

irregulare (Zygnema), VII, 8; 43 

irregularis (MougeoUa), XVIII, 15-16; 106 

irregularis (Spirogyra), XXVI, 3; 168 

iyengarii (Zygnemopsis), IX, 2-3; 55 

jaoensis (Spirogyra), 177 

jaoi (Spirogyra), XXXIX, 12; 220 

jassiensis (Spirogyra), XXXII, 5; 192 

jatobae (Spirogyra), XXXII, 8-9; 194 

jogensis (Mougeotia), XIV, 9-10; 93 

juergensii (Spirogyra), I, i; XXI, 3; 151 

jugalis (Spirogyra), XXVIII, 4; 176 

kaffirita (Spirogyra), XXV, 11; 166 

kerguelensis (Mougeotia), XIV, i; 92 

INDEX 241 

khannae (Zygnema), D-E; 44 

kiangsiense (Zygnema), IV, 5; 29 

kumaoensc (Sirocladium), XX, 11-14; 119 

kumaoense (Zygogonium), XI, 16-19; 67 

kuusamciensis (Spirogyra), XXXVI, 7; 207 

kvvangsiensis (Mougeotia), 114 

kwangtungense (Zygnema), VII, 15; 43 

labyrinthica (Spirogyra), 167 

lacustris (Spirogyra), XXIII, 10; 159 

laetevirens (Mougeotia), XVI, 9-1 1 ; 100 

laetevircns (Zygnema), 26 

laevis (Mougeotia), XV, 17: 98 

laevisporum (Zygnema), II, 5-6; 23 

lagerheimii (Spirogyra), XXI V^, 7; 163 

lamberuana (Spirogyra), XXXVII, i; 209 

lamellata (Zygnemopsis), IX, 8-9; 56 

lamellosa (Mougeotia), XV, 18-19; 97 

lamellosa (Spirogyra), XXXVII, 16; 211 

latviensis (Spirogyra), 212 

lawtonianum (Zygnema), II, 9; 24 

laxa (Spirogyra), 211 

laxistrata (Spirogyra), XXXVII, i j; 209 

leiospermum (Zygnema), 32 

lenticularis (Spirogyra), XXXII, 

14-15; 195 

liana (Spirogyra), XXXIII, lo-ii: 197 

longata (Spirogyra), XXIII, 5; 158 

lushanensis (Spirogyra), XXXIII, 6; 199 

luteospora (Spirogyra), XXIV, 3; 162 

luteosporum (Zygnema), V, 2; 33 

lutetiana (Spirogyra), XXIII, 11-13; 160 

macrospora (Mougeotia), XIV, 15; 94 

macrospora (Spirogyra), XLI, 18; 221 

majus (Zygnema), 29 

majuscula (Spirogyra), XXXI, 14-15; 190 

malmeana (Spirogyra), XXX, 14-16; 186 

maltae (Mougeotia), XIV, 2; 92 

manoramae (Spirogyra), XXXII, 7; 194 

maravillosa (Spirogyra), XXVI, 1-2; 167 

marchica (Spirogyra), XLI, 22-23; 223 

margaritata (Spirogyra), XXVIII, 5; 176 

maxima (Spirogyra), XXXII, lo-ii; 194 

mayori (Mougeotia), XIX, 29; 113 

megaspora (Mougeotia), XV, 5; 96 

megaspora (Spirogyra), 195 

megasporum (Sirogonium), XL, 5; 233 

melanosporum (Sirogonium), XL, 8; 234 

melanosporum (Zygnema), 39 

miamiana (Mougeotia), XIX, 22-23; 112 

miamiana (Spirogyra), 180 

microgranulata (Spirogyra), XXXVII, 

2-3; 209 

micropora (Mougeotia), XV, 8; 96 

micropunctata (Spirogyra), XXXIV, 9; 200 

micropunctatum (Zygnema), IV, 7; 29 

microspora (Spirogyra), XXVI, 5; 168 

microverrucosa (Mougeotia), XV, 20; 97 

mienningensis (Spirogyra), XXIX, 6; 181


minor (Spirogyra), 184 

minuta (Zygncmopsis), VIII, lo-ii; 52 

minutifossa (Spirogyra), XXIV, in; 164 

mirabile (Zygogonium), X, 17-10: 66 

mirabilis (Spirogyra), XXIII, 4: 158 

mirandum (Zygncma), VI, 4; 37 

mirificum (Zygncma), R-C; 44 

mocbii (Spirogyra), 192 

momonicnsc (Zygncma), 29 

Mougcotia, 79-116 

species of 

-descriptions, 89-114 

-illustrations, 1, 10; XIII-XIX 

-key, 82-89 

-list, 114-16 

Mougeotiopsis, 73 74 

species of 



mucigenum (Zygncma), XLI, 6-7; 43 

narcissiana (Spirogyra), XXXV, 1-3; 202 

natchita (Spirogyra), 179 

nawashini (Spirogyra), 218 

ncglccta (Spirogyra), XXVII, 14-15; 175 

neocruciatum (Zygncma), 37 

neopectinatum (Zygncma), III, 8: 26 

nitida (Spirogyra), XXVII, 1-2; 171 

normani (Zygncma), V, 6; 34 

notabilis (Spirogyra), 185 

novae-angliac (Spirogyra), XXX, 7: 186 

nummuloides (Mougcotia), XV, 2-3; 95 

nyctigama (Spirogyra), XXXV, 18; 205 

oblata (Spirogyra), XXXII, 1-3; 192 

oblongata (Mougcotia), XVI, 8; 99 

obovata (Spirogyra), XXIV, 5; 162 

occidental is (Spirogyra), XXIV, 2; 162 

oedogonioides (Mougcotia), XVII, 

9-10; 102 

oltmannsii (Spirogyra), XXIII, 6; 159 

opclouscnsis (Mougcotia), XVI, 

13-15; 100 

opcrculata (Mougcotia), XVII, 11-12; 103 

orientalis (Spirogyra), XXIX, 3; 181 

oricntalis (Zygncmopsis), VIII, ^-5; 52 

ornata (Mougcotia), XV, 6-7; 96 

ornatum (Zygncma), VII, 2; 40 

ovalis (Mougcotia), XVII, 2-3: 101 

ovalispora (Mougcotia), XIV, 14; 94 

ovcidanum (Zygncma), II, 3; 22 

ovigera (Spirogyra), 186 

paludosa (Mougcotia), XIX, 17-18; 111 

paludosa (Spirogyra), XXIII, 3; 158 

papulata (Spirogyra), XXV, 3-5; 165 

paraguaycnsis (Spirogyra), XXIX, 

17-18; 183 

parvispora (Spirogyra), XXVI, 16; 171 

parvula (Mougcotia), XIII, 3-5; 89 

parvula (Spirogyra), XXII, 5-6; 155 

paschcriana (Spirogyra), XXXV, 

12-13; 204 

pawhuskac (Mougcotia), XVII, 24-25; 

103 

pawhuskac (Zygncma), IV, 10: 30 

pawneanum (Zygncma), VII, i; 40 

pcctinata (Zygncmopsis), IX, 18-21; 58 

pcctinatum (Zygncma), III, 6: 26 

pcctosa (Mougcotia), XVII, 4-6; 101 

pectosum (Zygogonium), XI, 1-3; 66 

pcipingensis (Spirogyra), XXXIX, 20; 221 

peliosporum (Zygnema), VI, 17; 39 

pcllucida (Spirogyra), XXXI, 8; 190 

pcrforans (Spirogyra), XXIV, 9; 163 

phacosporum (Sirogonium), H-K; 236 

plakountiosporum (Zygogonium), XII, 

9-11; 68 

plena (Spirogyra), XXVIII, 1-2; 176 

Pleurodiscus, 71 

species of 



poinciana (Mougcotia), XVII, 21; 104 

polycdrica (Debarya), XII, 24-26; 77 

polymorpha (Spirogyra), XXIII, 

14-15; 161 

poly taenia ta (Spirogyra), 177 

porangabae (Spirogyra), XXIV, 11; 164 

porticalis (Spirogyra), XXIII, 9; 160 

pratensis (Spirogyra), I, 7; XXII, 

14-18; 156 

prescottii (Spirogyra), 198 

proavita (Spirogyra), XXXVIII, 7; 215 

producta (Mougcotia), XIX, 5-6: 109 

prona (Mougcotia), XIX, 26-28; 112 

propria (Spirogyra), 187 

protecu (Spirogyra), XXXVII, 19; 212 

pscudofloridanum (Sirogonium), XL, 

6; 234 

pscudogranulata (Spirogyra), XXXIX, 

9; 220 

pscudoncglecta (Spirogyra), XXVI, 

13-14; 170 

pseudopectinatum (Zygncma), 25 

pseudorcticulata (Spirogyra), XLI, 

13-15; 222 

pseudosprcciana (Spirogyra), XXXV, 

11; 204 

pscudovarians (Spirogyra), XXI, 

12-14; 153 

pulchclla (Mougcotia), XVI, 1; 98 

pulchrifigurata (Spirogyra), XXIX, 

8-9; 182 

punctata (Mougcotia), XIX, 15; 110 

punctata (Spirogyra), XXXI\', 1; 199 

punctatum (Zygogonium), XI, 12; 67 

puncticulata (Spirogyra), XXVIII, 9; 178

punctiformis (Spirogyra), XXXIV, 

5-6; 200 

punctulata (Spirogyra), XXX, 11-13; 187 

quadrangulata (Mougeotia), XIX, 

19-20; 1 1 

quadrangulatum (Zygnema), VII, 14; 42 

quadrata (Spirogyra), XXXVI, 14-16; 208 

quadrata (Zygnemopsis), IX, 4-5; 56 

quadriiaminata (Spirogyra), XXIX, 

11-13; 182 

quinquelaminata (Spirogyra), XXXIX, 

lo-ii; 219 

ralfsii (Zygnema), IV, 6; 29 

rava (Mougeotia), XIX, 25; 113 

rectangularis (Spirogyra), XXXVIII, 

11-12; 215 

rectispira (Spirogyra), 196 

recurva (Mougeotia), XIII, 13; 91 

reflexa (Spirogyra), XXXIV, 7-8; 200 

regellii (Mougeotia), XIX, 7-8; 109 

regularis (Spirogyra), XXXVII, 11-12; 213 

reinhardii (Spirogyra), XXXI, 3-5; 189 

reinschii (Mougeotia), XIV, 3; 92 

reticulata (Hallasia), X, 1-9; 61 

reticulata (Spirogyra), XXXIX, 5; 218 

rhizobrachialis (Spirogyra), XXIX, 

14-16; 183 

rhizoides (Spirogyra), 178 

rhizopus (Spirogyra), XXVIII, 11-13; 179 

rivularis (Spirogyra), XXVI, 8; 169 

robusta (Mougeotia), XVI, 2-4; 98 

robusta (Spirogyra), XXIV, 14-15; 165 

rotundangulata (Mougeotia), XIX, 

13-14; 110 

rugosa (Spirogyra), 206 

rugulosa (Spirogyra), XXXIV, 14; 201 

sahnii (Spirogyra), 160 

sanfordiana (Mougeotia), XVI, 7; 99 

scalaris (Mougeotia), XIV, 7-8; 93 

schmidtii (Spirogyra), XXVIII, 19-20; 180 

schwabei (Zygnema), VII, 10; 42 

scripta (Spirogyra), XXX, 3-4; 184 

scrobiculata (Spirogyra), XXIV, 17; XXV, 

6-7; 165 

seminoleana (Mougeotia), XVII, 22; 103 

semiornata (Spirogyra), XXXV, 

15-16; 205 

setiformis (Spirogyra), XXVII, 4-5; 172 

shangtungcnsis (Spirogyra), XXIX, 7; 182 

siamensis (Spirogyra), 175 

sibirica (Spirogyra), XLI, 8-9; 222 

sikangensis (Zygnemopsis), VIII, 1-2; 52 

silvicola (Spirogyra), XXI, 7; 151 

sinense (Zygnema), III, i; 25 

sinense (Zygogonium), XII, 1-5; 67 

sinensis (Mougeotia), XV, 4; 95 

INDEX 243 

sinensis (Spirogyra), XXXI, 10; 190 

sinensis (Zygnemopsis), VIII, 24; 54 

singularis (Spirogyra;, XXI, 4; 151 

Sirocladium, 119 

species of 


-illustrations, XX, 11-14 

sirogonioides (Spirogyra), XXXIII, 

7-8; 199 

Sirogonium, 231-36 

species of 


-illustrations, XL; G-K 

-key, 232 

-list, 236 

skujae (Spirogyra), XXIV, 12; 164 

skujae (Zygnema), 24 

smithii (Debarya), XII, 27-28; 77 

smithii (Spirogyra), XXVIII, 17-18; 180 

sphaerocarpa (Mougeotia), XIV, 4-6; 92 

sphaerocarpa (Spirogyra), XXXIX, 

17-18; 221 

sphaerospora (Spirogyra), XXXI, 9; 189 

sphaerospora (Zygnemopsis), IX, 6-7; 56 

spiralis (Zygnemopsis), IX, 16; 57 

Spirogyra, 123-229 

species of 


-illustrations, I, i, 3-5, 7; XXI-XXXIX; 

XLI, 8-23; F 

-key, 129-50 

-list, 223-29 

splendens (Zygnemopsis), VIII, 25; 55 

splendida (Spirogyra), XXVII, 17; 174 

spontaneum (Zygnema), VII, 5-7; 41 

spreeiana (Spirogyra), XXXVII, 4-6; 210 

stagnale (Zygnema), 31 

stellinum (Zygnema), I, 8; V, 16; VI, i ; 36 

stephensiae (Zygnemopsis), IX, i; 55 

stephensiae (Zygogonium), XLI, 1-5; 69 

sterile (Zygnema), VII, ii; 41 

sticticum (Sirogonium), XL, 1-4; G; 233 

subcrassa (Mougeotia), XIV, 18; 94 

subcruciamm (Zygnema), V, 7; 34 

subcylindricum (Zygnema), VII, 13: 43 

subcylindrospora (Spirogyra), XXIX, 

4-5; 181 

subfanicum (Zygnema), V, 15; 35 

submarina (Spirogyra), 169 

submaxima (Spirogyra), 191 

subpaludosa (Mougeotia), XIX, 32; 113 

subpapulata (Spirogyra), XXV, 1-2; 165 

subpellucida (Spirogyra), XXXIX, 19; 221 

subreticuiata (Spirogyra), XXIX, 

19-21; 183 

subsalina (Spirogyra), XXII, 9; 157 

subsalsa (Spirogyra), XXIII, 2; 158 

substellinum (Zygnema), V, i; 32 

subtile (Zygnema), 31

244 

succica (Spirogyra), XXIII, 7; 159 

sulcata (SpiroRvra), XXI\'. 4; 162 

sumatrana (Mougcotia), XV, 12: 96 

suomiana (Spirogyra), XXXIV, 4; 200 

supcrvanans (Spirogyra), XXII, 7: 154 

synadclphum (Zygncma), IV, 1-2; 28 

szcchwanensis (Spirogyra), XXVIII, 

3; 176 

taftiana (Spirogyra), XXIV, 8; 163 

talguppcnsc (Zygogonium), XI, 7-8; 66 

talyschcnsis (Mougcotia), XV, 13; 97 

taylorii (Spirogyra), XXXIII, 9; 197 

Tcmnogametum, 1 17-1 

species of 

—descriptions, 1 18 

-illustrations, XX, i-io 

-key, 117 

tenerriina (Mougcotia), XIX, 30-31; 111 

tenuc (Zygncma), IV, 14-15; 32 

tenuissima (Mougcotia), XIII, 2; 89 

tenuissima (Spirogyra), XXXV, 5-6; 203 

tenuius (Sirogonium), 232 

teodoresci (Spirogyra), XXI, 8; 153 

tcrrcstrc (Zygncma), VII, 16-18; 28 

tetrapla (Spirogyra), XXXIX, 4; 218 

texcnsis (Spirogyra), XXXIII, 5; 196 

thaxteri (Tcmnogametum), XX, 7-9; 118 

tholosporum (Zygncma), IV, 13; 32 

thylespora (Mougcotia), XVIII, 6-8; 106 

tiflFaniana (Zygnemopsis), VIII, 22-23; 54 

tjibodensis (Spirogyra), 211 

tolosana (Spirogyra), XXXVIII, 3; 214 

torta (Spirogyra), XXIX, 10; 182 

trachycarpa (Spirogyra), 187 

transcaui (Mougcotia), XVII, 19-20; 104 

transcaui (Tcmnogametum), XX, 5-6; 118 

iranseauiana (Spirogyra), XXXVIII, 

10; 215 

transeauiana (Zygnemopsis), IX, lo-ii; 56 

transcauianum (Zygncma), 35 

triplicata (Spirogyra), 174 

tropica (Mougcotia), XIX, 2i; 112 

tsingtaoensis (Spirogyra), XXXVII, 7; 210 

tubcrculata (Spirogyra), 166 

tubifcra (Mougcotia), XIII, 6-9; 90 

tumida (Spirogyra), XXXVII, 9; 210 

tumidula (Mougcotia), XIX, g-iir. 109 

turfosa (Spirogyra), XXVI, 17; 171 

ubcrosperma (Mougcotia), XVIII, 

9-10; 106 

ulcanum (Tcmnogametum), XX, 1-4; 118 

ZYC^NEMATACEAE 

unduliscpta (Spirogyra), XXXV, 4; 203 

vaginatum (Zygncma), 34 

varians (Mougcotia), X\'I, 12; 99 

varians (Spirogyra), XXII, i; 153 

variformis (Spirogyra), XXI, 9-10; 152 

vauchcrii (Zygncma), V, 5; 33 

vclata (Spirogyra), XXIV, i; 161 

ventcrsicum (Sirogonium), XL, 7; 234 

vcntricosa (Mougcotia), XIX, 24; 112 

venusta (Spirogyra), XXXVII, 17-18; 212 

verrucosa (Spirogyra), XLI, 19; 223 

verrucosum (Zygncma), II, lo-ii; 24 

vcrruculosa (Spirogyra), XXX, 8-10; 186 

victoriensis (Mougcotia), XIII, 18; 91 

viresccns (Mougcotia), XIX, 16; 110 

viridis (Mougcotia), XIX, 3-4; 109 

visenda (Spirogyra), XXXIV, 15; 202 

wabashensis (Spirogyra), XXXIV, 13; 201 

wangi (Spirogyra), XXXVIII, 14-15; 216 

wcberi (Spirogyra), XXXV, 14; 205 

weiwitschii (Spirogyra), 170 

westii (Spirogyra), 162 

woilnyi (Spirogyra), 172 

wrightiana (Spirogyra), I, 4-5; XXVII, 

7-8; 173 

wuchangensis (Zygnemopsis), VIII, 

28-29; 55 

yunnancnse (Zygncma), 31 

yunnanensis (Spirogyra), XXVII, 9; 173 

Zygnema, 13-47 

species of 


-illustrations, I, 2, 6, 8-9; II-VII; 

XLI, 6-7; A-E 

-key, 17-22 

-list, 45-47 

Zygnemopsis, 49-59 

species of 

—descriptions, 52-58 

-illustrations, VIII-IX 

-key, 50-51 

-list. 58-59 

Zygogonium, 63-69 

species of 

-ilcscriptions, 65-69 

-illustrations, X, 10-19; ^'s ÎI> i-u; 

XLI, 1-5 

-key, 64-65 

-list, 69

PLATES

246 

ZY(;\KMATACEAE 

PLATE I 

Ri PRoiu cTivii Structlkls oh Zvgxemataceae 

Fig. I.—Akinetes of Spirogyra jucrgensii from Crystal Springs, Mis- 

sissippi, y\pril, 1925. The usual form of akinetes in this species is similar to 

that of the vegetative cells. Fig. 2.—Akinetes of a Zygnema found at 

Arcadia, Florida, February, 1931. Fig. 3.— Akinetes and zygospore of Spiro- 

gyra jarlotvii from Topinohee, Michigan, July, 1934. Figs. 4-5.—Vegetative 

cell and two aplanospores of Spirogyra wrightiana from Parahiba, Brazil, 

July, 1934. Fig. 6.—Vegetative cell and two aplanospores of Zygnema frig- 

idum from Smithville, Oklahoma, May, 1932. Fig. 7.—Aplanospores of 

Spirogyra pratensis from Charleston, Illinois, May, 191 2. On two of the spo- 

rangia figured are outgrowths that suggest the initials of conjugating tubes. 

In many species these outgrowths are alternately or spirally arranged in suc- 

cessive cells. When present they occur in only some of the sporangia. 

Fig. 8.—Zygospores and parthenospores of Zygnema stcllnium from 

Charleston, Illinois, May, 1912. This camera-lucida drawing also demon- 

strates the distance between filaments through which conjugation may take 

place. Fig. 9.—Aplanospores and zygospores of Z.ygnema cruciatam from 

Coffeen, Illinois, May, 1915. Note that aplanospores occur in both male 

and female filaments. Fig. 10.—Four zygospores of Mougeotia drouetii 

from Fortaleza, Ceara, Brazil, October, 1935. This figure exemplifies sev- 

eral species in which the cytoplasmic residues form a film enclosing the 

zygospores.

PLATE 1 247.

248 

ZYGNEMATACEAE 

PLATE II 

Zygnema 

Fig. I.—Usual aiul unusual chromatophores in a filament of Zygnema 

collected near Fort Myers, Florida. Fig. 2.—Chromatophorc patterns in 

iilaments from West Point, Mississippi, and Pittsburgh, Pennsylvania. 

Fig. 3.—Z. oveidanum from Florida, zygospore, parthenospore, and ap- 

pearance of chromatophores during conjugation. Fig. 4.—Z. himalayense 

from India, scalariform and lateral conjugation and zygospores. In lateral 

conjugation the gametes unite through the end walls. After Randhawa. 

Figs. 5-6.—Z. lacvispoi-um, vegetative cell, scalariform and lateral conjuga- 

tion, and mature zypospore from Falmouth, Massachusetts. After Jao. 

Fig. 7.—Z. decussatum, three zygospores and adjoining gametangia from 

Charleston, Illinois. Fig. 8.—Z. conspicuutn , zygospores and gametangia, 

from central Illinois. Fig. 9.—Z. lawtonianum, zygospores and gametangia 

from Medicine Park, Oklahoma. After Taft. Figs, io-ii.—Z. verrucosum, 

zygospores, gametangia, and details of spore wall, from Szechwan, China. 

After Jao. Fig. 12.—Z. chungii, zygospore patterns from Wuchang, China. 

After Li.

PLATE ir 249

250 

ZYGNEMATACEAE 

PLATE III 

Zygnema 

Fig. I.—Z. sinense, zygospores and gametangia from Szechwan, China. 

After Jao. Figs. 2-3.—Z. globosuni, conjugation pattern and detail of spore 

walls from Bohemia. After Czurda. Fig. 4.—Z. adpectitnitum, gametangia 

and zygospore from Charleston, Illinois. Fig. 5.—Z. areolatum, gametangia 

and zygospores from Smithville, Oklahoma. Fig. 6.—Z. pectinatum, scalar- 

iform and lateral conjugation, aplanospore, and zygospores with spore wall 

markings, from Cofileen, Illinois. Fig. 7.—Z. excrassum, zygospores and 

gametangia from Casey, Illinois. Fic. 8.—Z. neopectinatum , gametangia 

and zygospore from Illinois. Figs. 9-10.—Z. giganteiitn, aplanospore. zygo- 

spores and parthenospores from Punjab, India. Modified after Randhawa. 

Figs. 11-12.—Z. gedeanum, lateral conjugation, zygospore, and partheno- 

spores from Java. After Czurda. Figs. 13-14.—Z. czurdae, zygospores after 

partial disintegration of the gametangial walls, from Punjab, India. After 

Randhawa.

PLATE III 251

252 

zygnemataceaf: 

PL ATI-. IV 

ZvGNhMA 

Figs. 1-2.—Z. synadelphuin, zygospores and vegetative cells enclosed by 

pectic sheath with prominent structural lines. Figure i from Latvia, after 

Skuja; Fig. 2 from Douglas Lake, Michigan. Figs. 3-4.—Z. coirulvum 

zygospores and gametangia, and spore wall pattern, trom Bohemia. After 

Czurda. Fig. 5.—Z. }{iangsiense, zygospores and gametangia from China. 

After L. C. Li. Fig. 6.—Z. ralfsii, conjugation pattern after G. S. West. 

Fig. 7.—Z. micropunctatum , zygospore and gametangia from Douglas Lake, 

Michigan. Figs. 8-9.—Z. circumcarinatum , zygospore and details of spore 

wall from Bohemia. After Czurda. Fig. 10.—Z. paivhusl{ae, gametangia 

and zygospores from Oklahoma. After Taft. Fig. ii.—Z. carinaturn, zygo- 

spores and gametangia from Oklahoma. Fig. 12.—Z. extenuc, zygospores 

and beginning of lateral conjugation from Szechwan, China. After Jao. 

Fig. 13.—Z. tholosporum, zygospore from Uruguay. After Magnus and 

Wille. Figs. 14-15.—Z. tenue, zygospores, gametangia, and details of spore 

wall from China. After Jao. Fig. 16.—Z. cylindrospermum , zygospores and 

gametangia from the Shetland Islands. After W. & G. S. West. Figs. 17- 

18.—Z. hausmannii, zygospores and gametangia from Austria. After 

Czurda.

PLATE IV 253

ZYCiNEMATACHAE 

PLATE V 

Zygnema 

Fig. I.—Z. substcllinitni , vegetative cells and the enlarged receptive 

gametangia from Bartlesviile, Oklahoma. Fic. 2.—Z. lutcosporum, gam- 

etangia and zygospore from Bohemia. After Czurda. Fig. 3.—Z. fiuvum, 

zygospore, vegetative cells, and akinete from Eden, Texas. After Taft. 

Fig. 4.—Z. calosponim, zygospores and vegetative cell from Szechwan, 

China. After Jao. Fig. 5.—Z. vaucherii, gametangia and zygospores from 

Cape Cod, Massachusetts. Fig. 6.—Z. normani, zygospore and gametangia 

from Norman, Oklahoma. After Taft. Fig. 7.—Z. iubcriiciatiim, zygo- 

spores and gametangia from China. After Jao. Figs. 8-9.—Z. germanictim 

zygospores and gametangia from Germany. After Czurda. Figs. 10-12. 

Z. insignc, conjugation patterns and zygospores. After Jao, and de Bary. 

Figs. 13-14.—Z. janicutn, scalariform conjugation and zygospores from 

China. After Li, and Jao. Fig. 15.—Z. subjanicum, zygospore and gam- 

etangia from China. After Jao. Fig. 16.—Z. stellinum, aplanospores and 

zygospores from Starkville, Mississippi, April, 1925. Note relative length of 

aplanosporangia and gametangia. (See also Plate I and Plate VI.)

PLATE V 255

256 

ZVGNEMATACEAE 

PLATE \'I 

ZvCNliNfA 

Fig. I.—Z. stt'/linuni, zygospores formed by lateral and scalaritorm con- 

jugation frt)ni Illinois. (See also Plates I and V for figures of partheno- 

spores and aplanospores.) Fig. 2.—Z. cylmdrosporuni, zygospores and 

gametangia from Macedonia. After Czurda. Fig. 3.—Z. bohcmtcum, 

gametangia and zygospores from Bohemia. After Czurda. Fig. 4.— Z. 

mirandum, zygospores, vegetative cell, and akinete, from Austin, Texas. 

After Taft. Fig. 5.—Z. inconspicuum, zygospores and gametangia from 

Manchuria. After Czurda. Figs. 6-7.—Z. aassiuscidum , zygospores and 

details of spore wall from Cape Town, South Africa. Fig. 8.—Z. chalybeo- 

spermum, lateral and scalariform conjugation, with resulting zygospores 

from Bohemia. Modified from Czurda. Figs. 9-10.—Z. cyaneum, scalar- 

iform and lateral conjugation from Bohemia. After Czurda. Figs. 11-13. 

Z. collinsianum, zygospores in relation to gametangia, zygospore, and 

aplanospore with details of spore wall markings from central Illinois. 

Fig. 14.—Z. excompressum, zygospores and sjx)re markings from Bohemia. 

After Czurda. Fig. 15.—Z. azureum, zygospores and gametangia from 

Medford, Oklahoma. After Taft. Fig. 16.—Z. carinthiacum, zygospore, 

gametangia, and spore wall markings from Szechwan, China. After Jao. 

Fig. 17.—Z. peliosporum, zygospores and gametangia from Alabama.

PLATE VI 257

2

PLATE VII 259

26o ZYCJNEMATACEAE 

PLATE VIII 

Zygnemopsis 

Figs. 1-2.—Z. sil{angensis, vegetative cells and zygospores from Yiin- 

nan, China. After L. C. Li. Figs. 3-5.—Z. orientalis, vegetative cells, 

immature and mature zygospores from northern India. After Carter. 

Figs. 6-7.—Z. gracilis, vegetative cells and aplanospores from Fyzabad, 

India. After Randhawa. Figs, 8-9.—Z. ftoridana, zygospores in face and 

lateral views, from Florida. Figs, io-ii.—Z. minuta, zygospore and aplan- 

ospores from Michigan. Figs. 12-14. ^'- desmidioides, zygospores, face 

and edgewise views, and vegetative cells from Latvia. After Skuja. Figs. 

15-17.—Z. Columbiana, zygospores in face and edgewise views, and an 

aplanospore from British Columbia. Figs. 18-21.—Z. amcricana, various 

forms of zygospores and a pair of parthenospores from Ontario, Canada. 

Figs. 22-23. ^- ti§(iniana, zygospores from Fort Myers, Florida. Fig. 24. 

Z. sinensis, vegetative cell and zygospore from Hupeh, China. Fig. 25.—Z. 

splcndcns, zygospore from Fyzabad, India. After Randhawa. Figs. 26-27. 

Z. indica, zygospore and aplanospore from Hamira, India. After Randhawa. 

Figs. 28-29.—^- wuchangcnsis, zygospore and vegetative cell from Hupeh, 

China. After L. C. Li.

PLATE VIII 261

262 ZYGNEMATACHAF. 

PLATH IX 

Zygnemopsis 

Fig. I.—Z. stephensiae, two zygospores from Cape Colony, South 

Africa. Figs. 2-3.—Z. iycngarii, zygos{X)res and aplanospores from Fyzabad, 

India. Drawn from type material. Figs. 4-5.—Z. quadrata, zygospores 

from Szechwan, China. After Jao. Figs. 6-7.—Z. splnicrospora, zygospores 

from Fyzabad, India. After Randhawa. Figs. 8-9.—Z. lamellata, face and 

lateral views of zygospores from India. Drawn from type material. Figs. 10- 

II.—Z. transeauiana, aplanospores and vegetative cell trom Fyzabad, India. 

After Randhawa. Figs. 12-15.—^- decussatu, vegetative cells, zygospores, 

parthenospores, and aplanospores from Ilinois. Fig. 16.—Z. spiralis, group 

of zygospores from Michigan. After Prescott. Fig. 17.—Z. jcrtilis, aplan- 

ospores from South Africa. After Fritsch and Rich. Figs. 1H-21.—Z. pcc- 

tinata, variations in chromatophores and aplanospores from Kentani, South 

Africa. Fig. 22.—Z. hodgettsii, immature a|>lanospores from Stellenhosch, 

South Africa. After Hodgetts.

PLATE IX 263

264 

ZYGNEMATACEAE 

PLATE X 

Hallasia and Zygogonium 

Figs. 1-9. Hallasia reticulata, vegetative cells and aplanospores. In 

some of the aplanospores secondary spores are formed which are released by 

the separation of the two valves of the aplanospore wall. In Fig. 9 a several- 

celled sporeling is depicted. After Hallas. Figs. 10-16. Zygogonium 

ericetorum, vegetative cells, akinetes, aplanospores, and zygospores in various 

stages of development. All but Fig. 14 are from Longwood, Florida. In 

Fig. 14 are filaments with an aplanospore and three encysted and united 

gametes, from Kwangtung, China. Figs. 17-19. Z. mirabile, zygosporangia 

and vegetative cells from Portuguese West Africa. After G. S. West.

PLATE X 265 

'^=S

266 

ZYGNEMATACEAE 

PLATE XI 

Zygogonium 

Figs. 1-3.—Z. pcctositm, zygospores and gametangia, modes of branch- 

ing, and aplanospore from Louisiana. After Taft. Figs. 4-6.—Z. /uinsgirgii, 

filaments with aplanospores and spore markings, from India. After 

Schmidle. Figs. 7-8.—Z. talguppcnsc, sporangia aiul aplanospores from 

India. After Iyengar. Figs. 9-1 i.—Z. capensc, aplanospores and sporangia, 

details of spore wall, from Stellenbosch, South Africa. After Hodgetts. 

Fig. 12.—Z. punctatum , zygospore and elongated gametangia from Louisi- 

ana. After Taft. Figs. 13-15.—Z. heydrichii, lateral conjugation and zygo- 

spores, release of spore through separation of two halves of sporangium 

wall, and akinete from Sydney, Australia. After Schmidle. Figs. 16-19. 

Z. \umaoer7se, aplanospores and branching filament from northern India. 

After Randhawa.

PLATE XI 267

268 ZYC;.\HMATACEAE 

PLATE XII 

ZVGOGONIUM, PlLURODISCUS, MoLGhOTIOPSIS, AND DiBARYA 

Figs. 1-5. Zygogoniutn sincnsc, zygospores, vegetative cells, partheno- 

spores, lateral conjugation, and resulting zygospore; also remnants of 

sporangium wall after escape of zygospore; details of spore wall. Figs. 6- 

8. Z. exuvielUjorme, zygospores formed by lateral and scalaritorni con- 

jugation, and details of spore wall, from Colombia, South America. After 

Jao. Figs. 9-11.—Z. plaf{ountiosporum, zygospores formed by lateral and 

scalariform conjugation. Note bilateral asymmetry of spore wall markings 

from Colombia, South America. After Jao. Figs. 12-15. Pleurodiscus 

borinqmnae , vegetative cells with disc-shaped chromatophores; zygospores 

and details of sporangium and spore walls from Puerto Rico. .After Tirfany. 

Figs. 16-17. Mougeotiopsis calospora, vegetative cells with chromatophores 

in different positions; zygospores with characteristic deep pits in the spore 

wall from Latvia. After Skuja. Figs. 18-19. Debarya glyptosptrma, 

arched gametangia and zygospores from Sweden. Figs. 20-21. D. acl{lcy- 

ana, face and side views of zygospores from Michigan. Figs. 22-23.—D. 

costata, zygospores in face and side views from Fyzabad, India. Figs. 24- 

26.—D. polyedrica, zygospores and gametangia from Yunnan, China. After 

Skuja. Figs. 27-28. D. smithii, vegetative cell and mature zygospore; 

lower figure shows growth of the two chromatophores and the multiplica- 

tion of pyrenoids during the early stages of conjugation, from Fresno, 

California. Figs. 29-30.—D. hardyi, conjugating gametangia and immature 

spore; cannot be placed in this genus with certainty until mature zygospores 

are lound.

PLATE XII 269

zy(;nemataceae 

PLATE XIII 

MoUGEOTIA 

Fig. I. M. angusta, gametangia and zygospore. ;\tter Hassall. Fig. 2. 

A/, tcnuissima, zygospore and gametangia. After de Bary. Figs. 3-5 M. 

parvula, zygospores and subtending gametangia from Finland; third figure, 

aplanospore and sporangium from Burgaw, North Carolina. Figs. 6-9. 

M. tubijera, figures in order illustrate an early stage in conjugation; usual 

form of mature zygospore; zygospore resulting from conjugation through 

lateral wall of one of the tubes; the last exemplifies a pair of tubes that 

failed to unite and produced a pair of parthenospores. Note that the tubes 

have about the same diameter as the vegetative cells. The cells are too long 

to be illustrated on this plate. Specimens from Wilmington, North Carolina. 

Figs. 10-12. M. calcarea, aplanospore, three zygospores, and the form of 

zygospore which has been distinguished as "bicalyptrata."" First two figures 

after Wittrock. Fig. 13. M. recurva, usual position of zygospore between 

gametangia. Fig. 14.—M. ellipsoidea, zygospore and gametangia. After 

G. S. West. Figs. 15-17. M. adnata, zygospores resulting from scalariform 

and lateral conjugation, from India. After Iyengar. Fig. 18.— .\/. victor- 

iensis from Australia, gametangia and zygospore enclosed by thick pectic 

layer. After West. Fig. 19.—A/, chlamydata, zygospore with remnants of 

outer layer of sporangium wall surrounding each half of the conjugating 

tube, from Ecuador. After Prescott. Fig. 20.—A/, cotopi/xitnsis, zygospore 

pattern, from volcano Cotopaxi, Ecuador. After Prescott.

PLATE XIII 271

272 

ZYGNEMATACEAE 

PLATE XI\' 

MoUGEOTIA 

Fig. I. M. fêrguclcnsis, zygospores and gamctangia Iroiii ihc Klt- 

guelen Islands, in the southern Indian Ocean. After Krieger. Fig. 2. M. 

maltae, zygospore and gametangia from Latvia. After Skuja. Fig. 3. 

A/, reinschii, zygospore by lateral conjugation, from central Illinois. Figs. 

4-6.—M. sphaerocarpa, zygospores, parthenospores, and aplanospores from 

Columbus, Ohio. The walls of the gametangia and tubes are often greatly 

thickened, and the cytoplasmic residues may form a veil around the zygo- 

spore as in Fig. 5. Figs. 7-8.—A/, scalaris, zygospore by scalariform con- 

jugation and parthenospore after incomplete lateral conjugation, from 

Michigan. Figs. 9-10.—A/, jogensis, zygospores after scalariform and lateral 

conjugation, from India. After Iyengar. Figs. 11-12.—A/, ajncana, aplan- 

ospore and zygospore from the Philippine Islands. Fig. 13.—A/, hirnii, 

zygospore and gametangia from Finland. After Hirn. Fig. 14.—A/, ort//- 

/j/jo/w, zygospore and gametangia from Germany. After Krieger. Fig. 15. 

A/, macrospora, zygospore and gametangia from Pennsylvania. After Wolle. 

Figs. 16-17.—^^- gt^nuflcxa, zygospores by lateral and scalariform conjuga- 

tion, from Illinois. Fig. 18.—A/, siibcrassa, zygospore and gametangia from 

Australia. After G. S. West.

PLATE XIV 273

274 

ZYCINEMATACEAE 

PLATE X\' 

Mot'GEOTIA 

Fig. I.—A/, aiclcstis, zygospore and two aplanospores with local thick- 

ening of sporangial walls, from Miami, Oklahoma. Figs. 2-3. M. num- 

muloides, three aplanosporangia with characteristic bend where the spore 

is formed, and a zygospore and gametangia, troni Burgaw, North Carolina. 

Fig. 4.—A/, sinensis, two zygospores with reticulate median spore wall, from 

Tinghai, China. After Li. Fig. 5. M. mcgaspora, zygospore and gam- 

etangia, from Sweden. After Wittrock. Figs. 6-7.—A/, ornata, zygospores 

and detail of spore walls, from Szechwan, China. After Jao. Fig. 8.—M. 

micropora, zygospore and gametangia, from Oklahoma. Figs. 9-1 i.— 

A/, areolata, aplanospore, zygospore, and details of spore wall, from Oveida 

Springs, Florida. Fig. 12. M. sumatrana, zygospore and gametangia, from 

Sumatra. After Schmidle. Fig. 13. M. talyschensis, zygospores and gam- 

etangia, from Baku, U.S.S.R. After Woronichin. Fig. 14. M. gotlandica, 

zygospore with characteristic spore markings, from Sweden. After Wittrock. 

Figs. 15-16.—A/, globulispora, zygospore and details of spore wall, from 

Szechwan, China. After Jao. Fig. 17. M. laevis, zygospore and gam- 

etangia, from England. After Archer. Figs. 18-19. M. lamellosa, zygo- 

spore, gametangia, and spore wall details, from Szechwan, China. After 

Jao. Fig. 20.—A/, microverrucosa, zygospores and gametangia from Ger- 

many. After Kricger.

PLATE XV 275

276 ZYCNFAfATACEAE 

PLATE XVI 

MOUGEOTIA 

Fig. I.—A/, pulchclla, vegetative cell and zygospores from Douglas 

Lake, Michigan. Figs. 2-4.—M. robusta, vegetative cells, zygospores, and 

gametangia Irom Winchester, Massachusetts. A cell in which the chro- 

matophore has divided completely with the nucleus between the halves is 

represented in Fig. 4. One not infret]uently Hnds chromatophores ot this 

and a few other species with ends cleft to various depths. Fig. 5.—.V/. day- 

tonae, zygospore and gametangia from Daytona, Florida. Fig. 6. M. 

handelii, zygospore, gametangia, and vegetative cell from Yiinnanfu, China. 

After Skuja. Fig. 7. M. sanjordiana, from Daytona, Florida. Fig. 8. 

M. oblongata, a pair of zygospores with attached gametangia from Fort 

Myers, Florida. Figs. 9-11. M. laetevirens, two forms of zygospore and 

an aplanospore from Long Island, New York. Fig. 12. M. varians, zygo- 

spore from Sweden. After Wittrock. Figs. 13-15. M. opelousensis, three 

zygospores seen at different angles, from Opelousas, Louisiana. After Taft. 

Fig. 16.—A/, angolensis, zygospore from Angola, Africa. After West. 

Fig. 17. M. gelatinosa, zygospore wifh pectic sporangium wall from 

Sweden. After Wittrock.

PLATE XVI 277

.78 

ZYGNEMATACEAE 

PLATE XVII 

MOUGEOTIA 

Fig. I.—A/, depressa, zygospore and garhetangia from Germany. After 

Kiitzing. Figs. 2-3. M. ovalis, gametangia and zygospore, and details of 

spore wall. After Wittrock and Nordstedt. Figs. 4-6. M. pectosa, zygo- 

spore and aplanospores from Fort Myers, Florida. Figs. 7-8.—A/, disjuncta, 

zygospores, one with change of sporangium wall to pectic compound, the 

other without. Specimens from Fort Myers, Florida. Figs. 9-10. M. 

oedogonioides, zygospores resulting from lateral and scalaritorm conjugation. 

Note unique remnants of conjugating tubes. Figs. 11-12.—A/, operculata, 

gametangia, zygospore, and details of spore wall from Florida. Figs. 13- 

14.—A/, atubulosa, zygospores in pectic-walled sporangia, and details of 

spore wall from Java. After Krieger. Figs. 15-17.— A/, cycmeii, zygospores, 

and aplanospore, and details of spore wall from Michigan. Fig. 18.—A/. 

caimani, part of group of interconjugating filaments from Haiti. Figs. 19- 

20. M. transeaui, two forms of zygospores and an aplanospore from Illinois. 

Fig. 21. M. poinciana, zygospores and an aplanospore from Fort Myers, 

Florida. Differs from the preceding only in having larger dimensions. 

Fig. 22. M. seminoleana, zygospore and aplanospore from Fort Myers, 

Florida. Fig. 23. M. cherokeana, zygospores and arching gametangia from 

Oklahoma. Figs. 24-25. M. pawhuskjxe , gametangia and zygospores, and 

spore wall details from Oklahoma.

PLATE XVII 279

28o ZYGNEMATACEAE 

PLATK XVIII 

MOUGEOTIA 

Figs. 1-3. M. amcncana, zygospores and gametangia, and an aplanospore 

with its relatively long sporogenous cell from Oneida Lake, New 

York. Figs. 4-5.—M. corniculata, zygospore and vegetative cell from Bo- 

hemia. Modified from figure by Hansgirg. Figs. 6-8.—M. thylespora, 

zygospores and gametangia from Estonia. After Skuja. In Fig. 6 are aplan- 

ospores from Florida where zygospores were found with them. Figs. 9- 

10. M. uberosperma, vegetative cell, aplanospore, and zygospore from 

Kentani, South Africa. Figs. 11-14. M. craterophora, four zygospores 

from the Azores. After Bohlin. Figs. 15-16. M. irregularis, two zygo- 

spores from Angola, Africa. After West. Fig. 17. M. delicata, zygospore 

and gametangia from Austria. After Beck. Figs. 18-20.—M. granulosa, 

vegetative cell, parthenospore, and two zygospores from Cape Town, South 

Africa. Figs. 21-22.—A/, elegantula, zygospores and an aplanospore. Fig. 

21 after Wittrock. Figs. 23-25.—M. boodlei, two aplanospores and the 

very rare zygospore, from Charleston, Illinois. Figs. 26-31. M. capucina, 

vegetative cell, zygospores, an aplanospore, and a parthenospore. The last 

figure shows scalariform conjugation between two adjacent cells, from 

Tupper Lake. New York.

PLATE XVIII 281


PLATE XIX 

MOUGEOTIA 

Figs. 1-2.—A/, grciril/inui, aplanospore and zygospore from Oneida 

Lake, New York. Figs. 3-4. M. viridis, aplanospore and zygospore from 

Saugatuck, Michigan. Figs. 5-6. M. producta, aplanospore and zygospore 

from Burma. After West. Figs. 7-8.—M. rcgellii, zygospores, face and 

lateral views from Greece. After Skuja. Figs. 9-10. M. tumidula, zygo- 

spore, aplanospore, and vegetative cell from Illinois. Figs. 11-12.—A/, aus- 

tr'iaca, two zygospores from Wiener-Neustadt, Austria. After Czurda. 

Figs. 13-14. M. rotundangulata, zygospore and details of spore wall from 

Szechwan, China. After Jao. Fig. 15.—A/, punctata, zygospore from 

Sweden. After Wittrock. Fig. 16. M. virescens, zygospore from England. 

After Hassall. Figs. 17-18.—M. paludosa, two zygospores from England. 

After West. Figs. 19-20. M. quadrangulata, aplanospore and zygospore 

from Illinois. Fig. 21. M. tropica, aplanospore (in optical section) and a 

vegetative cell from Angola, Africa. After West. Figs. 22-23. ^- '"'^""'- 

ana, two forms of aplanospores from the same filament, from Miami, Okla- 

homa. Fig. 24. M. ventricosa, aplanospores from Sweden. After Wittrock. 

Fig. 25. M. rava, aplanospores variously placed in the sporogenous cell, 

from Starkville, Mississippi. Figs. 26-28. M. prona, vegetative cell, early 

stage of aplanospore formation, and mature aplanospores from High Hill, 

Long Island, New York. Fig. 29. M. mayori, an aplanospore from Colom- 

bia, South America. After West. Figs. 30-31. M. tenerrima, vegetative 

cell and aplanospore from Colombia, South America. Alter West. Fig. 32. 

M. suhpahidosa, zygospore from Kwangtung, China. After Ley.

PLATE XIX 283


PLATE XX 

Temnogametum, Sirocladium, and Entransia 

Figs. 1-4. Temnogametum uleanum, vegetative cells and gametangia, 

zygospores formed by scalariform and lateral conjugation, from Brazil. 

After Mobius. Figs. 5-6. T. transeaui, mature zygospores formed by scalar- 

iform and lateral conjugation; early stages similar to the preceding species, 

from Ecuador. After Prescott. Figs. 7-9.—T. thaxtert, vegetative cell, two 

gametangia, zygospore, and aplanospore from Trinidad, British West Indies. 

Fig. 10.—T. hetcYosporum, vegetative cell, lateral and scalariform conjuga- 

tion from Angola. After West. Figs. 11-14. Sirocladium kumao'ense, 

vegetative cells, three aplanospores, a parthenospore (Fig. 13), and a zygo- 

spore and gametangia from northern India. Drawn from type specimens. 

Fig. 15. Entransia fimbriata, vegetative cells with characteristic parietal 

chromatophores with nucleus between, from Nova Scotia. After Hughes.

PLATE XX 285


PLATE XXI 

Spirogyra 

Fig. I.—5. communis, gametangia and zygospores from Illinois. Fig. i. 

—5. intorta, conjugating filaments and zygospores from Szechwan, China. 

After Jao. Fic. 3. S. juergensii, typical gametangia and zygospores from 

Illinois. Fig. 4. S. singularis, gametangia and zygospores from Illinois. 

Fig. 5.- S. gracilis, gametangia and zygospores from Ohio. Fig. 6. S. 

jragilis. gametangia and zygospores. Note separation of receptive gam- 

etangia following conjugation, from Szechwan. After Jao. Fig. 7. S. sil- 

i'icola, gametangia and zygospores from northern Illinois. After Britton. 

Fig. 8. S. teodorcsci, gametangia and zygospores from Illinois. Figs. 9- 

10. S. vartjormis, vegetative cell, gametangia, and zygospores variously 

deformed by the gametangial walls from Cape Town, South Africa. 

Fig. II. S. condensata, lateral and scalariform conjugation, vegetative cell, 

and zygospores from Charleston, Illinois. Figs. 12-14.—5. pseudovarians, 

gametangia, zygospores, and optical section of spore wall from Czecho- 

slovakia. After Czurda.

PLATE XXI 287


PLATE XXII 

Spirogyra 

Fig. I. S. varians, gametangia, zygospores, and inflated sterile cell 

from central Illinois. Fig. 2. S. bicalyptrata, gametangia and zygospores 

from Czechoslovakia. After Czurda. Fig. 3. S. circumlineata, gametangia, 

zygospores, and sterile cell from central Illinois. Fig. 4. S. jennicu, lateral 

and scalariform conjugation, and zygospores from Szechwan, China. After 

Jao. Figs. 5-6. S. parvula, scalariform and lateral conjugation, and an 

aplanospore from central Illinois. Fig. 7. S. supervarians, gametangia and 

zygospores from Cape Town, South Africa. Fig. 8. S. borgeana, gam- 

etangia and zygospores from Illinois. (See also Fig. 16, PI. XXIII.) Fig. 9. 

— S. subsalina, gametangia and zygospore from Finland. Figs, io-ii.—5. 

gibberosa, lateral and scalariform conjugation, separation of receptive gam- 

etangia, and zygospores from Szechwan. After Jao. Fig. 12. S. catenae- 

jormis, scalariform and lateral conjugation, and sterile cell from central 

Illinois. (See also Fig. 16, PI. XXIV.) Fig. 13. S. bullata, zygospores, 

gametangia, and sterile cells from Szechwan. After Jao. Figs. 14-18.—5. 

pratensis, vegetative cells, aplanosjwres, and zygospores. Note growth of 

cells during development of aplanosporangia of which there are two extreme 

types, also the bullate type of sterile cells. Type material from Charleston, 

Illinois.

PLATE XXII 289

290 

zv(;nemataceae 

PLATE XXIir 

Spirogyra 

Fig. I. S. fhivt'sccns, zygospores aiul gamctangia from Michigan. 

Fig. 2. S. subsalsa, gametangia and zygospore from Florida. Fig. 3. S. 

paludosa, gametangia and zygospores from Bohemia. After Czurda. Fig. 4. 

—5. mirabilis, zygospore (very rare) and aplanospore (the usual method of 

reproduction) from Douglas Lake, Michigan. Fig. 5. S. longata, zygo- 

spores and gametangia from China. After Jao. The spores are not always 

so long but are always ovoid. Fig. 6. S. oltmannsii, aplanospores and 

sporangia from South Africa. After Huber-Pestalozzi. Spores are "possibly 

scrobiculate" when mature. Fig. 7. S. suecica, gametangia and zygospores 

from Sweden. After Borge. Fig. 8.—5. gallica, gametangia and zygospores 

from France. After Petit. Fig. 9. S. porticalis, zygospores and gametangia 

from Illinois. Fig. 10. S. lacustris, gametangia, zygospore, and conjugating 

tubes from Austria. Figs. 11-13. S. lutetiana, various forms of zygospores 

from France. After Petit. Figs. 14-15.—5. polymorpha, zygospores, par- 

thenospores, and variously shaped gametangia from China. After )ao. 

Fig. 16. S. borgeana, a remarkably rare instance of conjugation through 

end walls of two filaments with two adjoining receptive gametangia of 

another filament. Figs. 17-18.—5. aplanospora, lateral conjugation and 

aplanospore formation from India. After Randhawa.

PLATE XXIII 291

292 

ZYCINEMATACEAE 

PLATE XXIV 

Spirogyra 

Fig. I. S. velata, spore wall pattern. After Jao. Fig. 2. S. occt- 

dentalis, gamctangia and zygospores from Illinois. Fig. 3. S. lutcospora, 

zygospore and receptive gametangium from Bohemia. After Czurda. Fig. 4. 

— S. sulcata, zygospores and gametangia from Wisconsin. After Blum. 

Fig. 5. S. obovata, gametangia and zygospores from Szechwan. China. 

After Jao. Fig. 6. S. asiatica, zygospore from Tibet. After Czurda. Fig. 7. 

—5. lagerheimii, lateral conjugation and zygospore from Sweden. After 

Wittrock. Fig. 8. S. tajtiana, gametangia, zygospore, and sterile cells from 

Texas. After Taft. Fig. 9. S. perjorans, gametangia and zygospores from 

Florida. Fig. 10. S. minutijossa, zygospore and gametangia from Massa- 

chusetts. After Jao. Fig. ii.— S. porangabae, gametangia, zygospores, and 

sterile cells from northern Brazil. Fig. 12. S. skjujae, gametangia and zygo- 

spores from India. After Randhawa. Fig. 13. S. hoehnei, gametangia and 

zygospore from Kentucky. Figs. 14-15. S. robusta, gametangia and zygo- 

spores from South Africa. After Nygaard. Fig. 16.—5. catenaejormis, a not 

uncommon form of a laterally conjugating filament from Illinois. Fig. 17. 

— S. scrobiculata, unusual form of receptive gametangia and conjugation 

through end wall of filament from Illinois.

PLATE XXIV 293

294 

ZYGNEMATACEAE 

PLATE XXV 

Spirogvka 

Figs. 1-2. S. subpapulata, zygospores, aplanosporcs, aiui sterile cells 

from Szechwan, China. After Jao. Figs. 3-5. S. papulata, scalariform and 

lateral conjugation, zygospores, and spore wall pattern from Szechwan. 

After Jao. Figs. 6-7. S. scrobiculata, scalariform conjugation, zygosjwres, 

and details of spore wall from Austria. After Czurda. Fig. 8. S. aphano- 

sculpta, scalariform conjugation and zygospores from Cireece. After Skuja. 

Figs. 9-10. S. daedalea, scalariform conjugation, zygos[x»res, and spore 

wall pattern, from Yugoslavia. After Czurda. Fig. ii.— S. fâffirita, zygo- 

spores and gametangia from South Africa. Fic. 12. S. ghosei, gametangia 

and mature zygospores from India. After Singh. Figs. 13-15. S. daedci- 

leoides, vegetative cell, lateral and scalaritorm (.onjiigation, and zygospores 

from Latvia. After Skuja.

PLATE XXV 295

296 

ZYGNEMATACEAE 

PLATE XX\'I 

Spirocyka 

Figs. 1-2. S. maiavillosa, vegetative cell and aplanospores from north- 

ern Brazil. Fic. 3. S. irregularis, gametangia and zygospores from Illinois. 

Fig. 4.—5. juellebornci, gametangia and zygospores from Nyassa Lake re- 

gion, Africa. After Schmidle. Fig. 5. S. microspora, zygospores resulting 

from lateral conjugation, from Szechwan, China. Alter Jao. Figs. 6-7.—5. 

hollandiae, gametangia and zygospores from New (luinea. After Taft. 

Fig. 8. S. rivularis, gametangia and zygospores from Kansas. Figs. 9-10. 

S. bijormis, lateral and scalariform conjugation and zygospores from China. 

After Jao. Figs. 11-12. S. hyalina, lateral and scalariform conjugation, and 

resulting zygospores, also a parthenospore from Mississippi. Figs. 13-14. 

S. pseudoneglccta, lateral and scalariform conjugation, and zygospores from 

Moravia. After Czurda. Fig. 15.—5. columbicma, gametangia and zygo- 

spore from Colombia, South America. After Czurda. Fig. 16. S. parvi- 

spora, gametangia and zygospores from Florida. After Wood. Fig. 17. S. 

turjosa, gametangia, zygospore, and vegetative cell from Spain. After Gay.

PLATE XXVI 297

298 

ZYGNEMATACEAE 

PLATE XXVII 

Spirogyra 

Figs. 1-2. S. nitida, gametangia and zygospores from Szechwaii, 

China. After Jao. Fig. 3. S. hymerae, vegetative cell, zygospore, and gam- 

etangia from Indiana. After Britton. Figs. 4-5. S. setijormis, gametangia 

and zygospore from Charleston, Illinois. Fig. 6. S. elliptica, zygospore and 

gametangia from Szechwan, China. After Jao. Figs. 7-8. S. wrightiana, 

vegetative cell, aplanospores, and sporangia from Parahiba, Brazil. Fig. 9. 

S. yunnanensis, zygospores and gametangia from Yiinnan, China. After 

L. C. Li. Fig. 10. S. hatillensis, zygospores and gametangia from Puerto 

Rico. Fig. ii.—5. ellipsospora, zygospore and vegetative cell from Illinois. 

Fig. 12. S. emilianensis, zygospores and gametangia from Massachusetts. 

Fig. 13. S. exilis, gametangia, zygospores, and sterile cell from lûrma. 

After West. Figs. 14-15. S. neglecta, zygospores and gametangia. Mod- 

ified after Czurda. Fig. 16. S. decimina, zygospores and gametangia. 

After Jao. Fig. 17. S. splendida, zygospore and gametangium. After G. S. 

West.

PLATE XXVII 299

300 Z^'(;NE\fATACF.AH 

PLATE XXVIII 

Spirogyra 

Figs. i-2.^.S'. plena, receptive gametangia and zygospores formed by 

lateral and scalaritorm conjugation from Burma. After West. Fig. 3. S. 

szcchwanensis, gametangia and zygospore from Chungking, China. After 

Jao. Fig. 4. S. jugalis, receptive gametangium and zygospore from Illinois. 

Fig. 5.—5. margaritata, receptive gametangium and zygospore from spec- 

imens collected at Dresden, (jermany. Fig. 6. S. bichromatophora, gam- 

etangia and zygospores from India. After Randhavva. Fig. 7. S. baileyi, 

gametangia and zygospores from Australia. After Schmidle. Fig. 8.—5. 

dubia, gametangia and zygospores. After Kiitzing. Fig. 9. S. puncticulata, 

zygospores and gametangia from Massachusetts. After Jao. Fig. 10. S. 

aequinoctialis, zygospore and gametangia from central Africa. After West. 

Figs. 11-13. S. rhizopus, zygospores, gametangia, holdfast, and details of 

spore wall, from Peiping, China. After Jao. Fig. 14. S. dictyospora, veg- 

etative cell, gametangia, and zygospores from Chungking, China. After Jao. 

Figs. 15-16.—5. ]ossa, gametangia, zygospore, and spore wall details from 

Massachusetts. After Jao. Figs. 17-18. S. smithii, gametangia, zygospores, 

and details of outer and inner layers of median spore wall. Figs. 19-20. S. 

schmidtii, zygospores and gametangia from Koh Chang, Siam. After West.

PLATE XXVIII 301

302 

zv(;nfmataceae 

PLATE XXIX 

Spikogvra 

Figs. 1-2. S. chungîngcnsis, gametangia, zygospores, and details of 

spore wall. After Jao. Pic. 3.—5. oricntalis, receptive gametangiutn and 

zygospore from Burma. After West. Fics. 4-5. S. subcylindrospora, gam- 

etangia, zygospore, and spore wall pattern, from Szechwan, China. After 

Jao. Fig. 6. S. nuenningcnsis, zygospore and gametangia from Yunnan, 

China. After Li. Fig. 7. S. shantungensis, zygospore and gametangia from 

China. After Li. Figs. 8-9.—5. pulchrifigurata, gametangia, zygospores, 

and spore wall details from Szechwan. Alter Jao. Fig. 10.—5. torta, gam- 

etangia and zygospores from Massachusetts. After Blum. Figs. 11-13. S. 

quadnlcitninata, zygospore, optical section of spore wall, and spore wall 

pattern, from Szechwan. After Jao. Figs. 14-16. S. rhizobrachialis, gam- 

etangia, zygospore, rhizoid, and spore wall pattern, from Chungking, 

China. After Jao. Figs. 17-18.—5. paraguayensis, zygospores and spore 

wall pattern from South America. After Borge. Figs. 19-21.—5. subretic- 

nlata, zygospore, optical section of spore wall, and spore wall pattern, from 

South Africa. After Fritsch.

PLATE XXIX 303

304 

ZYGNEMATACEAE 

PLATE XXX 

Spikogyka 

Figs. 1-2.—5. brunnca, gametangia, zygospores, and s[)orc wall pattern, 

from Transvaal. After Fritsch and Rich. Figs. 3-4. S. scripta, gametangia, 

and zygospores from Transvaal. After Nygaard. Fig. 5. S. fluviutdis, 

receptive gametangium and zygospore from Illinois. Fig. 6. S. grossii, 

zygospore from Yugoslavia. After Schmidle. Fig. 7. S. novae-angliae, 

gametangia and zygospore from New York. After Blum. Figs. 8-10. S. 

verruculosa, vegetative cell, zygospore, and spore wall pattern from Hang- 

chow, China. After Jao. Figs. 11-13. S. punctulata, vegetative cell, gam- 

etangia, zygospore, and cell wall details, from China. After Jao. Fics. 14- 

16. S. malmeana, gametangia, zygospores, and spore wall pattern from 

Brazil. After Borge. Figs. 17-18. S. echinospora, chromatophores, gam- 

etangia, zygospore, and median spore wall pattern from New Hampshire. 

After Blum. Figs. 19-20. S. d'lluta, conjugating filaments, and character- 

istic orientation of spores, also spore wall details. In part after Wood.

PLATE XXX 305


PLATE XXXI 

Spikogyra 

Figs. 1-2.—5. cchinata, zygospores, gamclangia, and details of spore 

wall from Montgomery, Iowa. After Blum. Figs. 3-5. S. reinhardii, veg- 

etative cell, gametangia, and spore wall patterns, from Brazil. After Borge. 

Fig. 6. S. hunanensis, chromatophores, gametangia, and zygospore from 

China. After Jao. Fig. 7. S. discoidea, vegetative cell, gametangia, and 

zygospores from Cape Town, South Africa. Fig. 8. S. pellucida, gam- 

etangia, and two views of zygospore from England. After West. Fig. 9.—5. 

sphaerospora, gametangia, conjugating tubes, and zygospores from Finland. 

After Hirn. Fig. id.— S. sinensis, gametangia and zygospore from Hang- 

chow, China. After L. C. Li. Figs. n-13. S. colligata, twisted filament, 

end walls of cells, gametangia, and zygospores from England. Alter 

Hodgetts. Figs. 14-15. S. majuscula, zygospores and an aplanospore from 

Illinois. Fig. 16. S. glabra, gametangia and zygospores from V'ienna, 

Austria. After Czurda. Figs. 17-18.—5. bellis, gametangia, zygospore, and 

spore wall details. After Czurda.

PLATE XXXI 307


PLATE XXXII 

Spirogyra 

Figs. 1-3. S. oblata, vegetative cell, gametangia, zygospores, and de- 

tails of spore wall structure from Hangchow, China. After Jao. Fig. 4. S. 

jormosa, zygospores and receptive gametangia from Illinois. Fig. 5. S. jas- 

siensis, lateral conjugation and zygospores from Bessarabia. After Teo- 

doresco. Fig. 6.—5. crassa, receptive gametangia and zygospores from 

France. After Petit. Fig. 7.—5. manoramae , gametangia and zygospores 

from India. After Randhawa. Figs. 8-9. S. jatobae, receptive gametangia, 

zygospores, and vegetative cell from Brazil. Figs, io-ii.— S. maxima, 

zygospores and spore wall pattern from South America. After Borgc. 

Figs. 12-13. S. heeriana, gametangia and zygospores, also spore wall pat- 

tern, from Vienna, Austria. After Czurda. Figs. 14-15. S. lenticularis, 

receptive gametangia, zygospores seen from different angles, and spore wall 

pattern, from Cape Town, South Africa.

PLATE XXXII 309

3IO ZYCJNHMA'rACEAH 

PLATl'. XXXIII 

Spirocvra 

Fic. I. S. crassoidea, two views of zygospore from Illinois. Figs. 2-4. 

—5. hydrodictya, zygospores and gametangia after scalariform conjugation; 

early stage in lateral conjugation. Note unusual thickness of the tuhe walls. 

Specimen from Coffeen, Illinois. Fig. 5. S. texensis, gametangia and zygo- 

spore from Karnac, Texas. After Taft. Fig. 6. S. lushanensis, zygospores 

and gametangia from China. After Li. Figs. 7-8. S. sirogonioides, scalar- 

iform and lateral conjugation with resulting zygospores from Charleston, 

Nova Scotia. After Hughes. Fig. 9. S. taylorii, gametangia and zygospores 

from Massachusetts. After Jao. Figs, io-ii.—5. liana, lateral and scalar- 

iform conjugation and zygospores from China. Figs. 12-13.—'^- collinili, 

zygospores formed by lateral and scalariform conjugation from Mississippi. 

Fig. 14.—5. chenii, lateral and scalariform conjugation, zygospores, and 

sterile cell from Szcchwan, China. After Jao.

PLATE XXXIII 311

312 

ZYGNEMATACEAE 

PLATE XXXIV 

Spirogvka 

Fig. I. S. punctata, vegetative cells, gametangia, and zygospores trom 

China. After Jao. Figs. 2-3.—5. tsthonua, conjugating filaments and me- 

dian spore wall, from Estonia. After Skuja. Fig. 4. S. suomiana, zygo- 

spore and gametangia from Finland. After Hirn. Figs. 5-6.—5. puncti- 

jormis, vegetative cells, zygospores, and spore wall details from Illinois. 

Figs. 7-8. S. reflexa, gametangia and zygospores from Illinois. The lower 

figure illustrates an example of "cross conjugation." Fig. q.^S. micro- 

punctata, zygospores and gametangia from Illinois. Figs, io-ii.—5. cor 

rugata, vegetative cell, conjugating tube, zygospore, and spore wall details. 

In part after Jao. Fig. 12. S. hungarica, scalariform conjugation and zygo- 

spores from Sopron, Hungary. After Langer. Fu;. 13. S. wabashensis, 

gametangia and zygospores from Brownsville, Illinois. After Tiffany. 

Fig. 14. S. rugulosa, gametangia and zygospores from Bologoe, Russia. 

After Ivanof. Fig. 15. S. visenda, vegetative cell, gametangia, and zygo- 

spore from (x)lumhus, Mississippi.

PLATE XXXIV 313

314 

ZYCJNEMATACEAE 

PLATE XXXV 

Spikogvka 

Figs. 1-3.—5. narcissicina, vegetative cell with seiiiireplicate end walls, 

aplanospores, and sporangia from Charleston, Illinois. Fig. 4.—5. unduli- 

septa, zygospores and gametangia from Upper Punjah, India. Figs. 5-6. S. 

tenuissima, zygospores and gametangia trom China. After Jao. Figs. 7-8. 

— S. inflata, lateral and scalariform conjugation, and resulting zygospores 

from China. After Jao. Aplanospores from Illinois. Figs. 9-10. S. cylin- 

drica, lateral and scalariform conjugation with resulting zygospores from 

Austria. After Czurda. Fic. 11. S. pscudosprceiana, gametangia and zygo- 

spore from Szechwan, China. After Jao. Figs. 12-13.—5. pascheriana, 

lateral and scalariform conjugation and resulting zygospores from Czecho- 

slovakia. After Czurda. Fig. 14. S. weberi, gametangia and zygospores 

from (lermany. After Czurda. Figs. 15-16. S. semiornatu, lateral and 

scalariform conjugation, and resulting zygospores from China. After Jao. 

Fig. 17. S. hopciensis, gametangia and zygospore from North China. 

After Jao. Fig. 18. S. nyctigama, vegetative cell, gametangia, and zygo- 

spores from Cape Colony, South Africa. Figs. 19-20. S. grei'ilUanu, lateral 

and scalariform conjugation from Bohemia. After Czurda.

PLATE XXXV 315

3i6 ZYCINEMATACEAE 

PLATE XXXVI 

Spirocvra 

Fig. I. S. chuniiw, zygospores and gametangia from (!!hina. After Jao. 

Figs. 2-4. S. incrassata, lateral and scalariform conjugation and details of 

spore wall from Berlin. After Czurda. Fig. 5.—5. jovcolata, zygospore and 

gametangia from Latvia. After Skuja. Fig. 6.—5. discreta, zygospore and 

gametangia from central Illinois. Fig. 7.—5. \uusamoensis, gametangia 

and zygospores from Finland. After Hirn. Figs. 8-9. S. amplcctcns, 

lateral conjugation and details of spore wall Irom China. After Skuja. 

Figs. 10-13. ^- g'oenlandica, vegetative cell, lateral and scalariform con- 

jugation, zygospores, and an aplanospore from Boston, Massachusetts. 

Figs. 14-16.—5. quadrata, scalariform and lateral conjugation, and resulting 

zygospores from Szechwan, China, after Jao; the aplanospores were collected 

in Illinois. Figs. 17-18. S. dentireticulata, zygospores and details of spore 

wall from China. After |ao. Figs. 19-20. S. jritsch'uina, zygospores and 

gametangia from South Africa. After Fritsch and Rich. Fig. 21. S. goetzei, 

zygospores and receptive gametangia from Lake Nyassa. After Schmidle.

PLATE XXXVI 317

3i8 zv(;\i;mata(:i-..\k 

PLATE XXX \' 1 

Spik()(;vi

PLATE XXXVII 319

320 

ZYGNEMATACEAE 

PLATE XXXVIII 

Spirogyra 

Fig. I. S. licvcLinci, gametangia and zygospores troin S/.cchwan, C^hina. 

After Jao. Fig. 2. S. areolata, gametangia and zygospore from central 

Illinois. Fig. 3.— i'. tolosana, zygospores and gametangia from Indiana. 

Fig. 4.-5. hcissaUii, lateral conjugation and zygospore from Szechwan, 

China. After lao. Figs. 5-6. S. hartigii, scalariform and lateral conjuga- 

tion, conjugating tubes, and zygospores. After Kiitzing. Fig. 7.—5. proarita, 

lateral conjugation and tube. After Langer. Figs. 8-9. S. gratiana, straight 

conjugating filaments, scalariform and lateral conjugation, zygospores, and 

aplanospores. Fig. iu.— S. transeauiana, gametangia and zygospore from 

Szechwan, China. After Jao. Figs. 11-12.—5. rectangulans, scalariform 

and lateral conjugation with resulting zygospores from central Illinois. 

Fig. 13. S. jallax, gametangia and zygospores from Bohemia. After Hans- 

girg. Figs. 14-15. S. wangi, vegetative cell, gametangia, and zygospore 

from Hangchow, China. After Li. Figs. 16-17. ^- acanthophora, gam- 

etangia, zygospores, and details of spore wall from Latvia. After Skuja, 

Figs. 18-20. S. inconstans, lateral and scalariform conjugation with result- 

ing zygospores, and details of spore wall from Casey, Illinois. Note in 

Fig. 19 an almost complete absence of the reticulum on the spore wall. This 

depicts the extreme variation from Fig. 20.

PLATE XXXVIII 321

322 

ZVCXKMATACEAE 

PLATE XXXIX 

Spirogvra 

Figs. 1-3. S. borysthcnicci, gametangia, zygospore, and optical sections 

of spore wall from Ukraine. After Kasanofsky and Smirnoff. Fig. 4. S. 

tetrapla, vegetative cell, gametangia, and zygospores from central Illinois. 

Fig. 5. S. reticulata, gametangia, and zygospore with outer Jiiedian wall 

partly cut away exposing the reticulations on the inner median wall from 

Brazil. Fig. 6.—5. crassivallicularis, gametangia and zygospore from Massa- 

chusetts. After Jao. Figs. 7-8. S. granulata, vegetative cell, receptive gam- 

etangium, and zygospore from Szechwan, China, .\fter Jao. Fig. 9. S. 

pseiidogranulata, receptive gametangium and zygospore from Tong-Kau, 

China. After Ley. Figs, io-ii.— S. quinqucUiminata, gametangia, zygo- 

spore, aplanospore, and details ot spore wall, Ironi Szechwan, China. After 

jao. Fig. 12. S. jaoi, gametangia and zygospore from Tong-Kau, China. 

After Ley. Fig. 13. S. che /(îangen sis, gametangia and zygospore from 

W'enchow. China. After Jao. Figs. 14-16. S. crassispina, scalarilorin and 

lateral conjugation, zygospores, conjugating tubes, and details of spore wall 

from Haimen, (-hina. .After Jao. Figs. 17-18.—5. sphacrocarpa, gametangia 

and zygospores, trom VW-nchow, China, .\tter Jao. Fig. 19.—5. subpel- 

lucida, gametangia and zygospores from Wenchow. After Jao. Fig. 20. S. 

pcipingen sis, gametangia, and zygospores Irom China. After Jao.

PLATE XXXIX 323

324 

Z^'CNFMATACHAH 

PLATE XL 

SlROGONllM 

Figs. 1-4.—5. sticticun), various types ot conjugalion ami zygospores. 

The Hrst three figures based on collection from Mayhew, Mississippi: {a) 

two pairs ot equal gametangia, {b) conjugation between pairs of the larger 

subdivisions ol the progametangia, (r) zygospore from three gametes 

54 /x X 144/1. Alternating pairs of conjugants between long and short 

gametangia, from India. After Randhawa. Fig. 5.—5. megasporum, gam- 

etangia and zygospore from Szechwan, China. After Jao. Fig. 6. S. pscudo- 

floridanum, gametangia and zygospore from Wisconsin, .\fter Prescott. 

Fig. 7. S. ventcrsicum, gametangia and zygospore from the Transvaal. 

Fig. 8. S. melutiosponim, gametangia and zygospore from India. After 

Randhawa. Fig. 9.—5. indicum, zygospore and gametangia from India. 

After Singh. Figs, io-ii.— S. hut, vegetative cell, zygospore, and details 

of spore wall from Kiangsi, China. After L. C. Li. Figs. 12-13. S. tlli- 

noicnsc, early stage in conjugation with pectic ring around adhesion disc, 

mature zygospore, and subtending gametangia. On some spores the retic- 

ulum is less prominent than in this figure.

PLATE XL 325

326 

ZVCiNHMATACEAE 

PLATE XLI 

/yg(k7onium, Zygnema, and Spirogvka 

Figs. 1-5. Zygogonium stephensiae, \egetati\'e cells, and gamctangium 

(note relative length); iinmaturc and mature zygospores by scalariform 

conjugation; conjugation through end wall and mature spore; and the only 

instance of lateral conjugation seen in the abundant collections from Cape 

Colony. Figs. 6-7. Zygnema mucigeniim, scalariform and lateral conjuga- 

tion, and mature spores from northern India. After Randhawa. Figs. 8-9. 

—Spirogyra sibiriia, bullate sterile cell, scalariform conjugation, zygospores, 

and spore wall markings from Lake Zaisan region, Russia. After Skvortzof. 

Figs, io-ii.—5. czurdae, scalariform conjugation, zygospores, and spore 

markings from Kashmir, India. After Misra. Fig. 12. S. australensis, 

vegetative cells and zygospore from Australia, Queensland. After Mobius. 

Figs. 13-15. S. pseudoreticulata, lateral and scalariform conjugation, spore 

form, and details of spore markings. After Borge. Fig. 16. S. azygospora, 

aplanospores, and sporangia from north India. After Singh. Fig. 17. S. in- 

signis, vegetative cell, gametangia, and zygospore. After Petit. Fig. 18. 

5. macrospora, spores and gametangia from India. After Rao. Fig. 19.—5. 

verrucosa, gametangia and zygospores from central India. After Rao. Figs. 

20-21. S. indica, lateral and scalariform conjugation. After Rao. Figs. 22- 

23. S. marchica, mature spores following scalariform and lateral conjuga- 

tion. After Krieger.

PLATE XLI 327

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