Brittonia, 39(2), 1987, pp. 210-224. 9 1987, by the New York BotanicalGarden, Bronx, NY 10458-5126 TAXONOMIC AND NOMENCLATURAL REARRANGEMENT IN THE HOOKERIALES WITH NOTES ON WEST INDIAN TAXA WILLIAM R. BUCK Buck, William R. (New York Botanical Garden, Bronx, NY 10458-5126). Taxonomic and nomenclatural rearrangement in the Hookeriales with notes on West Indian taxa. Brittonia 39: 210-224. 1987.--The Hookeriales are evaluated to discern familial limits. Five families are recognized in the order: Hookeriaceae, Leucomiaceae, Daltoniaceae, CaUicostaceae, and Adelotheciaceae faro. nov. Chaetomitrium Dozy & Molk., Chaetomitriopsisfileisch., Dimorphocladon Dix., and Elharveya Crum are transferred to the Hypnaceae. Hookeriopsis (Besch.) Jaeg. is split into four genera: Hookeriopsis s. str., Brymela Crosby & Alien, Thamniopsis (Mitt.) Fleisch., and Trachyxiphium Buck, gen. nov. The following new combinations are proposed to coincide with the recognition of these four genera rather than Hookeriopsis s. lat.: Brymela acuminata, B. calIicostelloides, B. euspidata, B. fissidentoides, B. fluminensis, B. obtusifolia, B. parkeriana, B. rugulosa, B. websteri, Thamniopsis cheiloneura, T. cruegeriana, T. diffusa, T. incurva, T. langsdorflii, T. pappeana, T. purpureophylla, T. secunda, T. sinuata, T. terrestris, T. undata, T. utacamundiana, T. versicolor, Trachyxiphium aduncum, T. guadalupense, T. heteroicum, T. hypnaceum, T. pernutans, T. subfalcatum, T. tenue, T. vagum, and T. variable. Excluded species are treated as Isopterygium plumicaule, Schizomitrium cirrhosum, and S. subsecundum. Schizomitrium belangerianum (Besch.) Buck, comb. nov. is considered distinct from S. depressum (Hedw.) Buck & Steere, and S. pallidum (Hornsch.) Crum & Anders. is shown to have a smooth seta sometimes. The taxonomy of the aquatic species of Cyclodictyon Mitt. and Lepidopilum (Brid.) Brid. is clarified, resulting in the recognition of three species, Cyciodictyon subtortifolium (Bartr.) Buck, comb. nov., C. roridum (Hampe) Kuntze and L, tortifolium Mitt. Two new combinations are proposed in Calyptrochaeta Desv., C. setigera and C. albescens. Familial Limits F o r a n o r d e r t h a t is e s s e n t i a l l y t r o p i c a l , t h e H o o k e r i a l e s h a v e r e c e i v e d a surp r i s i n g a m o u n t o f a t t e n t i o n in r e c e n t years. T h e t r a d i t i o n a l t r e a t m e n t o f t h e o r d e r ( B r o t h e r u s , 1925) r e c o g n i z e s six f a m i l i e s : N e m a t a c e a e ( = E p h e m e r o p s i d a c e a e ) , Pilotrichaceae, Hookeriaceae, Symphyodontaceae, Leucomiaceae, and Hypopt e r y g i a c e a e . T h e N e m a t a c e a e w e r e p u t in t h e i r o w n s u b o r d e r , t h e N e m a t a c i n e a e , a n d t h e o t h e r five f a m i l i e s w e r e a c c o m m o d a t e d in t h e H o o k e r i i n e a e . M o r e rec e n t l y , M i l l e r (1971) r e e v a l u a t e d t h e o r d e r o n t h e b a s i s o f p e r c e i v e d t r e n d s in moss evolution, following a Besseyan approach. Because Miller used generalized t e n d e n c i e s for all m o s s e s r a t h e r t h a n o n e s t a i l o r e d f o r t h e H o o k e r i a l e s , h i s t r e a t m e n t is n o t v e r y helpful. M i l l e r r e c o g n i z e d n i n e f a m i l i e s : P i l o t r i c h a c e a e , H o o k e r i a ceae, Distichophyllaceae, Daltoniaceae, Symphyodontaceae, Leucomiaceae, Ephemeropsidaceae, Hypopterygiaceae, and Cyathophoraceae. Miller retained the E p h e m e r o p s i d a c e a e in its o w n s u b o r d e r ( E p h e m e r o p s i d i n e a e ) a n d p u t t h e H y p o p t e r y g i a c e a e a n d C y a t h o p h o r a c e a e in a s e p a r a t e s u b o r d e r ( H y p o p t e r y g i i n e a e ) . T h e n e w e s t s c h e m e , d e v e l o p e d b y C r o s b y (1974), h a s g a i n e d s o m e f o l l o w i n g . Crosby divided the Hookeriales into two families: Hookeriaceae and Daltoniaceae. He mechanically sorted the genera into one family or the other solely on the basis of exostomial ornamentation--the Daltoniaceae with papillose exostomes and the Hookeriaceae with cross-stfiolate ones. B u c k a n d V i t t (1986), in a n o v e r v i e w o f t h e p l e u r o c a r p o u s m o s s e s , m o s t l y neglected the Hookeriales. They did, however, transfer the Hypopterygiaceae into 1987] BUCK: HOOKERIALES 211 the Bryales, and the Symphyodontaceae into the Leucodontales. In their opinion neither Miller (1971) nor Crosby (1974) had proposed satisfactory phylogenies and so, as a short-term measure, they recognized within the Hookeriales only the Ephemeropsidaceae, Hookeriaceae, and Leucomiaceae. Neither Miller's (1971) nor Crosby's (1974) scheme seems reasonable, primarily because apparently closely related genera are often placed in different families while, at times, very different genera are allotted confamilial status. A more appropriate interpretation of the "daltoniaceous" peristome is that it represents the result of repeated modifications from the "hookeriaceous" peristome. Thus, while these modifications may have resulted from similar ecological pressures, the "daltoniaceous" peristome itself is polyphyletic. To understand the generic affinities of the West Indian Hookeriales, I have now studied all the genera of the Hookeriales (sensu Buck & Vitt, 1986). The present study evaluates both gametophytic and sporophytic characters in an attempt to recognize families on the basis of correlated features. Although some standard characters such as costal development and areolation seem to be reliable in a general way, these have been supplemented with such nontraditional characters as stem anatomy, axillary hair morphology, pseudoparaphyllia, and calyptral anatomy and ornamentation. Because peristomial reduction is rampant in the Hookeriales, exostomial ornamentation has not been utilized except as confirmational data. The following familial scheme represents only a preliminary sketch. It will be expanded at a symposium talk at the XIV International Botanical Congress in Berlin, and subsequently published in greater detail. The families I am recognizing in the Hookeriales are five, as follows: 1. HOOKERIACEAESchimp., nom. cons. Hookeriaceae Schimp., Coroll. Bryol.Eur. 101. 1855 [1856]. Plants mostly robust; stems without hyalodermis, mostly with + undifferentiated outer and inner cortex, central strand usually present; axillary hairs (2) 35-celled, the basal one small and brown, the apical ones hyaline and elongate; pseudoparaphyllia filamentous or absent. Leaves large, unbordered; costa single and forked or absent; cells large, short, lax, hexagonal, thin-walled, porose. Setae often short, smooth; annulus present; exostome teeth cross-striolate, furrowed or not. Calyptrae mitrate, not fringed, naked, 4-6 cells thick. Genera: Achrophyllurn Vitt & Crosby, Cyathophorella (Broth.) Fleisch., Cyathophorum P.-Beauv., Dendrocyathophorum Dix., Hookeria J. E. Sm., Schimperobryum Marg. The genera can be sorted into two lineages, one centered around Hookeria (Hookeria, Achrophyllum, and Schimperobryum), and another around Cyathophorum (Cyathophorum, Cyathophorella, Dendrocyathophorum). Although Buck and Vitt (1986) transferred the Hypopterygiaceae (including Cyathophorum and allied genera) to the Bryales, they did not evaluate the genera in the family. However, more careful study shows that Cyathophorum and Hypopterygium Brid. have little to do with one another. Hypopterygium, like most Bryales, differs from Cyathophorum in the strong, single costa, bordered leaves, nonporose cells, and cernuous capsules. The cyathophoroid genera also differ from Hypopterygium in the little- or unbranched stems, hexagonal leaf cells, short setae and multistratose calyptrae. Although Cyathophorurn and Hypopterygium have traditionally been associated on the basis of leaf arrangement, ranked leaves and reduced underleaves occur independently in both the Bryales and Hookeriales. 212 BRITTONIA [VOL. 39 2. LEUCOMIACEAEBroth. LeucomiaceaeBroth. in Engler & Prantl, Nat. Pfl. 1(3): 1095. 1908. Plants slender to robust; stems with little internal differentiation, central strand none; axillary hairs 2-celled, the basal one small and brown, the apical one elongate and hyaline; pseudoparaphyllia absent. Leaves unbordered, ecostate; cells elongate, lax, thin-walled, not porose. Setae elongate, smooth; annulus present; exostome teeth cross-striolate, furrowed; endostome with cilia. Calyptrae cucullate. Genera: Leucomium Mitt. and Rhynchostegiopsis C. Miill. Although this family is the only one in the order with cucullate calyptrae and endostomial cilia, all other features are typically hookerialean. The 2-celled axillary hairs, undifferentiated stem anatomy, lax leaf cells, lack of alar differentiation, collenchymatous exothecial cells, furrowed exostome teeth, and endostomial segments with baffle-like crosswalls all argue for an alliance in the Hookeriales. The endostomial morphology, not previously mentioned in the literature, seems unique within the pleurocarps. Typically, the crosswalls do not project, but are just seen as lines across the segments. However, in the Hookeriales these walls project into the keel of the segment so that the segments look something like a bamboo culm in longitudinal section. Although Crosby (1974) transferred Leucomium to the Hypnaceae and retained Rhynchostegiopsis in the Hookeriaceae, the two genera differ almost only in leaf margins (Rhynchostegiopsis--serrate; Leucomium--entire) and are surely very closely related. 3. DALTONIACEAESchimp. Daltoniaceae Schimp., Syn. Musc. Eur. 478. 1860. Plants mostly small; stems usually with poor differentiation between inner and outer cortex (occasionally with hyalodermis), central strand none; axillary hairs 3-4 (12)-celled, the basal one small and brown, the apical ones elongate and hyaline; pseudoparaphyllia absent. Leaves bordered; costa single, strong, rarely single and forked to absent; ceils short, mostly firm-walled. Setae elongate, often roughened; annulus present or absent; exostome cross-striolate and furrowed or, papillose, unbordered and not furrowed. Calyptrae mitrate, fringed, otherwise mostly naked, unistratose. Genera: Calyptrochaeta Desv., Crosbya Vitt, Daltonia Hook. & Tayl., Distichophyllidium Fleisch., Distichophyllum Dozy & Molk., Ephemeropsis Goeb., Leskeodon Broth., and Leskeodontopsis Zant. Despite peristomial differences, pairs of genera such as Daltonia and Crosbya, and Leskeodon and Distichophyllum, are obviously closely related as evidenced by virtually identical gametophytic morphologies. If one wishes to sort taxa purely on the basis of exostome ornamentation, then one has to assume very strong convergence of gametophytic structure. Calyptrochaeta is somewhat out of place in this alliance with its well structured stem anatomy and weak costa. However, the axillary hairs, bordered leaves, and fringed, unistratose calyptra argue for an alignment within the Daltoniaceae. Although Ephemeropsis has long been given familial, if not subordinal, status, it seems best situated here. It is an old genus, with a much wider range in antiquity, as evidenced by European fossils from the Eocene (K/Sck, 1939). However, Daltonia itself still occurs in Britain and Macaronesia and, like Ephemeropsis, probably also occurred on the European continent during the lower Tertiary. There is no reason to think that Ephemeropsis evolved from the stock which then later gave rise to all the rest of the Daltoniaceae, which 1987] BUCK" HOOKERIALES 213 is the necesary assumption to give it familial rank. Rather, it is probably reduced from a plant that would now be placed in the Daltoniaceae. Culture work and the use of desuppressant chemicals might provide interesting results (cf. Basile & Basile, 1984). 4. CALLICOSTACEAECrum CallicostaceaeCrum, Bryologist87: 210. 1984. Plants mostly medium-sized to robust; stem anatomy with inner and outer cortex well differentiated, sometimes with a hyalodermis, central strand none; axillary hairs 2-celled, the basal one small and brown, the apical one elongate and hyaline; pseudoparaphyllia present or absent. Leaves mostly not bordered; costa strong and double to absent, never single; cells often elongate, rarely isodiametric, smooth, papillose, or prorulose. Setae elongate or short, often roughened at apex; annulus present or absent; exostome teeth cross-striolate and furrowed or, papillose, often broadly bordered and not furrowed; endostome without or rarely with cilia. Calyptrae mitrate, not fringed, often hairy, often roughened above, unistratose. Genera: Actinodontium Schwaegr., Amblytropis (Mitt.) Broth., Brymela Crosby & Allen, Callicosta C. Miill., Callicostellopsis Broth., Crossomitrium C. Miill., Cyclodictyon Mitt., Diploneuron Bartr., Helicoblepharum (Mitt.) Broth., Hemiragis (Brid.) Brid., Hookeriopsis (Besch.) Jaeg., Hypnella (C. Miill.) Jaeg., Lepidopilidium (C. Mfill.) Broth., Lepidopilum (Brid.) Brid., Philophyllum C. Mfill., Pilotrichidium Besch., Saulorna (Hook.f. & Wils.) Mitt., Schizomitr]um B.S.G., Stenodesmus (Mitt.) Jaeg., Stenodictyon (Mitt.) Jaeg., Tetrastichium (Mitt.) Card., Thamniopsis (Mitt.) Fleisch., Trachyxiphium Buck, and Vesiculariopsis Broth. The Callicostaceae accommodate the majority of genera in the Hookeriales. All have strong double costae, or one that is reduced from it. It is odd that a family name for the double-costate genera only dates from Crum's (1984) replacement name for the illegitimate Pilotrichaceae Kindb.--which had been used only for a couple of not closely related genera. Indeed, Callicosta, in its best-known dendroid condition seems only distantly related to many of the other genera that are here placed in the family. However, some of the rarer, Lesser Antillean species are flaccid, not erect, with elongate leaves and cells, and scarcely crested costae. This morphology is not so different from that of some aquatic species of Schizomitrium. Similarly, Cyclodictyon with its well defined bordered and isodiametric leaf cells seems isolated. However, some of its aquatic and semiaquatic species are distressingly similar to the bordered species of Lepidopilum (see below). There appear to be two basic lines of evolution in the family: genera with and without a hyalodermis. In both lines the costa has been reduced or lost, and the exostomes have gone from cross-striolate to papillose. In the lineage without the hyalodermis (in which Schizomitrium is the largest genus), when the exostome becomes reduced, it is not or scarcely bordered (e.g., Callicosta). However, in t h e group with a hyalodermis, when the exostome is reduced it is strongly bordered (e.g., Lepidopilurn). Of note are some taxonomic differences between Crosby's (1974) work and the present treatment. Crosby synonymized Callicostellopsis with Helicoblepharum. However, the stronger costae, papillose (rather than smooth) leaf cells, and smooth (rather than spinose) setae argue for recognition of Callicostellopsis. Crosby synonymized Achrohypnella Herz. with Sauloma. Instead, the type and sole species, A. subenervis Herz., is a synonym of the type and sole species of Vesiculariopsis, V. spirifolium (Dus.) Broth. A new synonym of Sauloma, though, is Pulvinella 214 BRITTONIA [VOL. 39 Broth. & Herz. The only species, P. albicans Broth. & Herz., is a synonym of S. tenella (Hook.f. & Wils.) Mitt. Although Allen et al. (1985) have placed Tetrastichium in the Leucomiaceae because o f endostomial cilia, that interpretation has not been followed here. In Tetrastichium the differentiated outer stem cortex, not (or weakly) furrowed exostome teeth, and mitrate calyptra argue against an alliance with the Leucomiaceae. Rather, Tetrastichium's Macaronesian distribution gives reason to suspect that the genus may be relictual, and perhaps maintains a primitive character state. Under any circumstances, endostomial cilia alone are not sufficient evidence upon which to base evolutionary speculation. In a recent review of Hypnella, Crosby et al. (1985) transferred the genus to the Sematophyllaceae on the basis of leaf characters, especially the serially arranged papillae. However, they apparently chose to ignore the evidence that suggests a hookerialean alliance, for example, the strong, double costa, the lack of alar differentiation, the rough seta, the baffle-like crosswalls of the endostomial segments, and the mitrate calyptra. It is for these reasons that Hypnella seems best aligned with the Hookeriales, and it is left there without reservation. 5. ADELOTHECIACEAE Buck Adelotheciaceae Buck, fam. nov. Plantae complanatae. Caulium epidermis incrassata, filo centrali nullo, pili axillares 10-15-cellulares ceUulis omnibus brevibus hyalinis, pseudoparaphyllia filamentosa. Folia immarginata, costa unica, cellulae breves incrassatae porosae. Propagula ramis microphyllinis insidentia. Setae breves; capsulae erectae; exostomii dentes transverse striolati perforati. Calyptrae mitratae nonfimbriatae dense hirsutae unistratosae. Plants medium-sized; stems with well differentiated outer and inner cortex, without hyalodermis or central strand; axillary hairs 10-15-celled, all short and hyaline; pseudoparaphyllia filamentous, numerous. Leaves not bordered; costa single, strong; cells short, thick-walled, porose; propagula on specialized microphyllous branches. Setae short, roughened; annulus absent; exostome teeth crossstriolate, perforate. Calyptrae mitrate, not fringed, densely hairy, unistratose. Genus: Adelothecium Mitt. The Adelotheciaceae differ from the only other unicostate family, the Daltoniaceae, in the unbordered leaves and nonfringed, hairy calyptrae. The family differs from the Hookeriaceae, which can have a + single costa, in lacking a central strand and in having small, thick-walled leaf cells and unistratose calyptrae. It is distinct from all the families of the Hookeriales in the many-celled, hyaline axillary hairs and propagula borne on specialized microphyllous branches. The position of Bryobrothera ThOr. has not yet been resolved. In some ways it is similar to Adelothecium, and indeed may belong in the same family. Both genera have unbordered, unicostate leaves on stems without a hyalodermis. The exostome teeth are perforate, and the calyptrae are mitrate and hairy. However, Bryobrothera has 2-3-celled axillary hairs with a brown basal cell, an inclined capsule, and propagula on rhizoids. I know nothing firsthand of its habitat or ecology; additional material and study is needed. Excluded or U n k n o w n Genera Chaetomitrium Dozy & Molk., Chaetomitriopsis Fleisch., and Dirnorphocladon Dix. have been included in the Hookeriales on the basis of their mitrate calyptrae. However, the calyptrae are slender throughout, rather than expanded at the base as in other Hookeriales. In other words, they appear to represent a cucullate 1987] BUCK: HOOKERIALES 215 calyptra that does not split up one side. Also, there is a small but definitely differentiated alar region. The exostome teeth are cross-striolate, not furrowed, and the endostomial segments are without the hookerialean signature of bafflelike crosswalls. For these reasons, and others (e.g., areolation, leaf shape, margins, etc.), I prefer to place these three closely related genera in the Hypnaceae of the Hypnales. Two monotypic genera have recently been described from Mexico, both only known from sterile material (Crum, 1984, 1985). Elharveya Crum is known only from the type collection. Although the pale green color of plants and the lax areolation of the leaves are suggestive of the Hookeriales, a number of other morphological features argue against such an alliance. In cross-section the stems have small, thick-walled outer cells and a central strand. The only family of Hookeriales with a central strand is the Hookeriaceae. However, in that family the cortical cells are mostly not differentiated and the leaf cells, although lax, are much larger and the cell walls are porose. The pseudoparaphyllia, essentially filamentous, which Crum (1985) illustrated and prominently mentioned in the protologue, are also out of place in the Hookeriales, where foliose or lack of pseudoparaphyllia predominate. The axillary hairs in Elharveya are 4-celled, with the basal cell short and brown, and the apical cells elongate and hyaline. This condition is unlike most Hookeriales but completely in accord with the Hypnaceae, e.g., Ectropothecium Mitt. with identical axillary hairs and Vesicularia (C. Mfill.) C. Mfill. with similar ones but with only two apical cells. Elharveya and Vesicularia also share similar pseudoparaphyllia. Finally, although not conspicuous, the alar cells are decidedly differentiated in Elharveya, unlike any genus in the Hookeriales. Therefore, I place Elharveya in the Hypnaceae in the vicinity of Ectropothecium and Vesicularia. Curviramea Crum is based on Pilotrichum (=Callicosta) mexicanum ThOr., and was excluded from Pilotrichum Brid. by Crosby (1969), who suggested the Leucodontaceae as a possible family but made no formal nomenclatural transfer. The Leucodontaceae is an improbable home for the species on the basis of the strong double costa, non-rounded laminal cells and relatively small alar region. Except for the double costa, the genus might well be a member of the Hypnales. The well developed central strand and, at least seasonally, xeric habitat also help eliminate the Hookeriales as a possible affiliation. As unsatisfactory as it may be, placement of Curvirarnea must await the discovery of sporophytes. Hookeriopsis (Besch.) Jaeg. Hookeriopsis, as traditionally defined (Brotherus, 1925), is a diverse assemblage of species, many of which seem not at all or only slightly related to one another. Indeed, Hookeriopsis is little more than a dumping ground for residual Hookeriales not accommodated by other, relatively well defined genera. The genus is truly confusing because within what is here considered a single line of evolution, tremendous amounts of variation have occurred. This is further complicated by incredible species plasticity. Therefore, to make sense of the relationships among the West Indian species, a type study was undertaken of as many species as reasonably possible. Only after a majority of species were examined were trends perceptible. All types from NY and BM were examined and these account for about three-fourths of the described taxa. As a result of this study, several groups of species were recognized that are treated here as genera. Unfortunately, there is little assistance from sporophytic characters; peristomial features in many Hookeriales are uniform. 216 BRITTONIA [VOL. 39 Hookeriopsis was originally described by Bescherelle (1876) as a section of Hookeria for two Lesser Antillean species in which the costa is short and double and the leaf margins are subentire to serrulate. In the strict sense Hookeriopsis still has only these two original species, H. leiophylla (Besch.) Jaeg. and H. luteorufescens (Besch.) Jaeg., although each now has synonyms. They are plants of small stature with concave, unbordered leaves. The stem has no hyalodermis. Recently Crosby and Allen (1985) described Brymela for a single Panamanian species of exceptionally large stature and beauty. They compared it to a fairly similar species of Hookeriopsis, H. parkeriana (Hook. & Grey.) Jaeg., but argued for its generic segregation. Although on superficial, macroscopic features B. tutezona Crosby & Allen is distinctive, microscopically it shows close, significant similarities to a group of other tropical American mosses in Hookeriopsis s. lat., but here segregated as Brymela. These are characterized by large plants without enlarged epidermal cells of the stem. The leaves are almost always undulate and mostly acute, and not bordered by elongate cells. The costa is strong but either does not project or does so only slightly at its apex; it is never toothed. The margins are serrulate with the teeth not swollen or bifid. The leaf cells are very thick-walled and porose and homogeneous throughout the leaf. Brymela differs from Hookeriopsis s. str. by the much larger plants, much stronger costa, and more strongly serrulate leaves. Also, the plants are only rarely falcate (and then usually only homomallous), whereas they are often falcate in Hookeriopsis. The two genera are similar in the lack of a hyalodermis, unbordered leaves, and homogeneous leaf areolation. Thamniopsis is expanded to accommodate the largest group of Hookeriopsis s. lat. In fact, all Old World species fall into this group and several New World ones as well. Thamniopsis has a well differentiated, hyaline, thin-walled stem epidermis. The leaves vary from obtuse to short-acuminate and are bordered, usually obscurely so, by several rows of elongate cells. The upper margins, in all but a few species (including the type species), are strongly toothed. There is considerable variation in tooth morphology, ranging from teeth that are swollen, bifid, and short-celled to those that are not at all swollen, never bifid, and long-celled. However, almost every intermediate is possible. When looking at the two most common American species of Thamniopsis, T. incurva (Hornsch.) Buck and T. undata (Hedw.) Buck, it is hard to imagine them as congeneric. However, the Asian and African taxa show a complete range of intermediates between these two species and even the American T. cruegeriana (C. Miill.) Buck resembles T. undata in leaf structure but T. incurva in leaf marginal ornamentation. The costa in Thamniopsis often projects apically but only rarely is spinose as well. Also distinctive of Thamniopsis is the laminal areolation. The upper cells are often short, sometimes even isodiametric, and the basal (ca. 1/3)cells are elongate, often relatively abruptly so. In those species with acuminate leaf apices, with subsequently correlated elongate upper leaf cells, the basal cells are conspicuously broader, still giving evidence of a heterogeneous areolation. Thamniopsis differs from Hookeriopsis in its hyalodermis, bordered leaves, serrate leaf margins, strong costa, and heterogeneous areolation. It is likewise separated from Brymela, except that Brymela has a strong costa. Trachyxiphium is an American endemic with its greatest diversity in the northern Andes and eastern Brazil. It is characterized by mostly slender plants with an undifferentiated stem epidermis. In a few larger taxa, the stem epidermis may be differentiated but then the branch epidermis is not differentiated. The leaves are always flaccid and unbordered. They are mostly long-acuminate, often slenderly so, but may be only short-acuminate. The margins are typically armed with 1987] BUCK: HOOKERIALES 217 c l o s e l y - s p a c e d , s w o l l e n , bifid teeth. T h e c o s t a is s t r o n g a n d o f t e n h a s p a i r e d o r b i f i d t e e t h in t h e u p p e r p o r t i o n . T h e a r e o l a t i o n is e s s e n t i a l l y h o m o g e n e o u s a n d t h e u p p e r cells f r e q u e n t l y h a v e p r o j e c t i n g u p p e r e n d s ( p r o r u l a e ) . Trachyxiphium is s i m i l a r in s t a t u r e t o Hookeriopsis, a n d l i k e w i s e often h a s f a l c a t e - s e c u n d l e a v e s a n d o f t e n l a c k s a h y a l o d e r m i s . H o w e v e r , its l e a v e s a r e t y p i c a l l y s e r r a t e , flaccid, a n d n o t c o n c a v e ; t h e c o s t a is s t r o n g a n d o f t e n s p i n o s e . Trachyxiphium differs f r o m Brymela in its m u c h s m a l l e r s t a t u r e , a c u m i n a t e l e a v e s , s t r o n g l y s e r r a t e l e a f m a r g i n s , a n d less t h i c k - w a l l e d l e a f cells. Trachyxiphium is p r o b a b l y m o s t c l o s e l y r e l a t e d to Thamniopsis as e v i d e n c e d b y t h e s w o l l e n , b i f i d t e e t h o n t h e l e a f m a r g i n s a n d t h e d i f f e r e n t i a t e d s t e m e p i d e r m i s in a c o u p l e o f t h e l a r g e s t s p e c i e s o f Trachyx i p h i u m a n d all Thamniopsis species. H o w e v e r , it differs in t h e m u c h s m a l l e r s t a t u r e , a c u m i n a t e , u n b o r d e r e d leaves, m u c h m o r e s p i n o s e c o s t a , a n d h o m o g e neous areolation. K e y to t h e g e n e r a s e g r e g a t e d f r o m Hookeriopsis s. lat. 1 Stem with well defined hyalodermis; basal laminal cells different from apical ones .... Tharnniopsis 1 Stem without (or rarely with) hyalodermis; areolation homogeneous. 2 Leaves concave; costa short ........................................................................................................................................... Hookeriopsis 2 Leaves plane; costa strong. 3 Plants large; marginal teeth of leaves simple, not swollen; laminal cells porose, smooth; costa apex smooth or with a small spine .............................................................................................................. Brymela 3 Plants small; marginal teeth of leaves bifid, swollen; laminal cells not porose, often prorulose; costa apex often with prominent spines ................................................................... Trachyxiphium T h e f o l l o w i n g n o m e n c l a t u r a l n o v e l t i e s a n d a l t e r a t i o n s a r e n e c e s s a r y for t h e b r e a k - u p o f Hookeriopsis s. lat. O n l y t a x a f o r w h i c h t y p e s h a v e b e e n s t u d i e d a r e i n c l u d e d . W h e n a t y p e is a close, b u t n o t a n exact, m a t c h t o a n o t h e r , it is i n c l u d e d as a p r o b a b l e s y n o n y m . BRYMELA C r o s b y & A l l e n Brymela Crosby & Allen, Monogr. Syst. Bot. Missouri Bot. Gard. 11:211. 1985. TYPE: Brymela tutezona Crosby & Allen. Brymela acuminata ( M i t t . ) B u c k , c o m b . n o v . Hookeria acuminata Mitt., J. Linn. Soc., Bot. 12: 357. 1869. TYPE: ECUADOR. Andes Quitenses, ad ft. Bombonasa, Spruce 684 (HOLOTYPE:N~lr!). Brymela callicostelloides ( H e r z . & Th6r.) B u c k , c o m b . n o v . Hookeriopsis callicostelloides Herz. & Th6r. in Herz., Hedwigia 74:110. 1934. TYPE: PANAMA. Cerro Canajague, Apr 1929, Troll s.n. (ISO'rYPE:NY!). Hookeriopsis panamensis Bartr. in Willis, Bryologist 42: 156. 1939, syn. nov. TYPE: PANAMA. Barro Colorado Island, 1938, Willis s.n. (HOLOTYPE:FH!). Brymela cuspidata (Jaeg.) B u c k , c o m b . n o v . Hookeriopsis cuspidata Jaeg., Ber. T~itigk. St. Gallischen Naturwiss. Ges. 1875-1876: 359. 1877. Hookeria cuspidata Mitt., J. Linn. Soc., Bot. 12: 355. 1869, horn. illeg., non Dozy & Molk. (1844) nec C. Mfill. (1851). TYPE: ECUADOR. Andes Quitensis, Canelos, Spruce 682 (HOLOTYPE:NY!). Hookeriopsis laevinervis Ren. & Card., Bull. Soc. Roy. Bot. Belgique 32(1): 196. 1893 [1894], syn. nov. TYPE: COSTA RICA. Rio Naranjo, [1893, Tonduz s.n.] Pittier, Fl. Costaricensiss 5663 (ISOTYPE:N-Y!). Brymela f i s s i d e n t o i d e s ( H o o k . f . & W i l s . ) B u c k , c o m b . n o v . Hookeriafissidentoides Hook.f. & Wils. in Hook., Icon. P1. Rar. 8: 716A. 1845. TYPE: JAMAICA. Purdie s . n . (HOLOTYPE:BM!; ISOTYPE:NY!). Brymela f l u m i n e n s i s ( H a m p e ) Buck, c o m b . n o v . Hookeriafluminensis Hampe ex Geh., Nora 64:412.1881. TYPE:BRAZIL. Rio de Janeiro, Glaziou 11727 (ISOTYPE:NY!). 218 BRITTONIA [VOL. 39 Hookeria drepanophylla Geh. & Hampe ex Geh., Flora 64:411. 1881, syn. nov. TYPE: BRAZIL. SAo PAULO: Near Apiahy, Jun 1879, Puigarri 179, 192 (SYNTYPES: Both BM!). Brymela obtusifolia (Bartr.) Buck, comb. nov. Hookeriopsis obtusifolia Bartr., Contr. U.S. Natl. Herb. 26: 101. 1928. TYPE: COSTA RICA. PRov. HEREDIA: Cerro de las Caricias, Standley 52068 (HOLOTYPE:FH!). Brymela parkeriana (Hook & Grev.) Buck, comb. nov. Hookeria parkeriana Hook. & Grey., Edinburgh J. Sci. 2: 229. 1825. TYPE: GUYANA. Demerara, Parker s . n . (HOLOTYPE:BM!). Brymela rugulosa (Mitt.) Buck, comb. nov. Hookeria rugulosa Mitt., J. Linn. Soc., Bot. 12: 358.. 1869. TYPE: ECUADOR. Andes Quitenses, Canelos, Spruce 683, 670 (LECTOTVPE--designated here: 683, NY!; SYNTYPE: NY!). Brymela websteri (Crum & Bartr.) Buck, comb. nov. Hookeriopsis websteri Crum & Bartr., Bull. Inst. Jamaica, Sci. Ser. 8: 52. 1958. TYPE: JAMAICA. John Crow Mountains, 1.5 mi SW of Ecclesdown, Webster 5199 (HOLOTYPE:CANM!; ISOTYPE: FH!). THAMNIOPSIS (Mitt.) FIeisch. Thamniopsis (Mitt.) FIeisch., Musci ]71. Buitenzorg 3: 952. 1908; Hookeria sect. Callicostella subsect. Thamniopsis Mitt., J. Linn. Soc., Bot. 12: 338. 1869. TYPE: Thamniopsispendula (Hook.) FIeisch. Thamniopsis cheiloneura (C. Miill. ex Broth.) Buck, comb. nov. Hookeria cheiloneura C. MtilI. ex Broth., Bot. Jahrb. Syst. 24: 257. 1897. TYPE: CAMEROON. Bibundi, Dus~n s.n. (ISOTYPE: NY!). Thamniopsis cruegeriana (C. Miill.) Buck, comb. nov. Hookeria cruegeriana Sonder ex C. Mtill., Syn. Musc. Frond. 2: 208. 1851. TYPE: TRINIDAD. Monte Tamanaco, 10 Aug 1847, Criiger s. n. (LECTOXVVE--designated here: NY!). Thamniopsis diffusa (Wils.) Buck, comb. nov. Hookeria diffusa Wils. in Seemann, Bot. Voy. Herald 245. 1854. TYPE: PANAMA. 1847, Seemann S.~q. (ISOTYPE:NY!). Thamniopsis incurva (Hornsch.) Buck, comb. nov. Chaetephora incurva Hornsch., Horae Phys. Berol. 65. 1820. TYPE: CHILE. Chamisso 1487 (LECTOTYPE--designated here: BM!). Hookeriopsis subincurva Th6r., Mem. Soc. Cub. Hist. Nat. "Felipe Poey" 14: 369. 1940, syn. nov. TYPE: CUBA. Loma del Gato, Hioram 7260 (ISOTYPE:NY!). THAMNIOPSIS KILLIPII ( W i l l i a m s ) B a r t r . Thamniopsis killipii (Williams) Bartr., Contr. U.S. Natl. Herb. 26(3): 103.1928. TYPE: COLOMBIA. DPTO, VALLE: C6rdoba, Killip 5246 (HOLOTYPE: NY!). Hookeriopsis maguirei Bartr. in Mag., Wurd. & collab., Mem. New York Bot. Gard. 10(2): 9. 1960, syn. nov. TYPE: VENEZUELA. AMAZONAS: Cerro de la Neblina, Maguire, Wurdack & Maguire 42543b (ISOTYPE: NY!). Thamniopsis langsdorflii (Hook.) Buck, comb. nov. Hookeria langsdorffii Hook., Musci Exot. 2: tab. 121. 1819 (non Hypnum langsdorffii Hook. in Kunth (1822) =Mittenothamniurn, with which it has been nomenclaturally confused). TYPE: BRAZIL. Rio de Janeiro, Langsdorffs.n. (HOLOTYPE: BM!). Hookeria glaziovii Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn ser. 3, 6:158. 1875, syn. nov. TYPE: BRAZIL. Rio de Janeiro, Glaziou 7090 (XSOTYPE:NY!). Hookeria hornschuchiana Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn ser. 3, 6: 159. 1875, horn. illeg., non Hampe, 1844, syn. nov. TYPE: BRAZIL. Rio de Janeiro, Glaziou 6354 (HOLOTYPE: BM!). Hookeria caldensis Angstr., Ofvers. F6rh. Svenska Vetensk.-Akad. 33(4): 25. 1876, syn. nov. TYPE: BRAZIL. Caldas, Regnell 9 (mOTYPE: BM!). Hookeria luteo-viridis Besch., J. Bot. (Morot) 5: 344. 1891, syn. nov. TYPE: PARAGUAY. Cerro Le6n, Pirayu, Balansa 3638 (HOLOTYPE: BM!). Hookeria saprophila C. Miill. ex Broth., Bih. Kongl. Svenska Vetensk.-Akad. Handl. 21 Afd. 3(3): 41. 1895, syn. nov. TYPE: BRAZIL. Rio DE JANEmO: Corcovado, Mosdn 161 (HOLOTYPE: H-BR). 1987] BUCK: HOOKERIALES 219 Hookeriopsis schiffneri Broth., Denkschr. Kaiserl. Akad. Wiss., Math.-Naturwiss. KI. 83:327.1926, syn. nov. TYPE: BRAZIL. SAo PAULO:Apiahy, Schiffner 1890 (ISOTYPE:BM!). Thamniopsis pappeana (Hampe) Buck, comb. nov. Hookeria pappeana Hampe, Icon. Musc. 2. 1844. TYPE: SOUTH AFRICA. Zwellendam, Pappe s.n. (HOLOTYPE:BM!). Hookeria macropyxis Rehm. ex Geh., Rev. Bryol. 5: 70. 1878, nom. nud. Based on: SOUTH AFRICA. Rehmann 91 (NY!). Hookeria angolensis Welw. & Duby in Duby, M6m. Soc. Phys. Gen6ve 21: 442. 1871, prob. syn. TYPE: ANGOLA. PROV. PUNGO-ANDONGO:Near Pungo-Andongo, Welwitsch [108]; Prov. Golungo-Alto, Welwitsch [193] (SYNTYPES:Both BM!). Lepidopilum darntyi Schimp. ex Besch., Ann. Sci. Nat. Bot. s6r. 6, 10: 281. 1880, prob. syn. TYPE: MAURITIUS. Mont Pouce, Darnty 19 (HOLOTYPE:BM!). T h a m n i o p s i s p u r p u r e o p h y l l a (C. MOll. e x B r i t t . ) B u c k , c o m b . n o v . Hookeria purpureophylla C. M011. ex Bfitt., Bull. Torrey Bot. Club 23: 492. 1896. TYPE: BOLIVIA. Near Yungas, Rushy 3164 (HOLOTVPE:NY!; ISOTYPE:BM!). T h a m n i o p s i s s e c u n d a (Griff.) B u c k , c o m b . n o v . Hookeria secunda Griff., Calcutta J. Nat. Hist. 3: 280. 1843. TYPE: INDIA. Mumbree, 1835-1836, GriJfith s.n. (ISOTYPE:NY!). Lepidopilum purpuratum Mitt., J. Linn. Soc., Bot. Suppl. 1:116. 1859, prob. syn. TYPE: SIKKIM. Hooker 707 (HOLOTYPE:NY!). Hookeriopsis geminidens Broth., Philipp. J. Sci. C, 5: 156. 1910, prob. syn. TYPE: PHILIPPINES. LUZON: Prov. Benguet, Bacani (For. Bur. 15929) (ISOTYPE:NY!). Thamniopsis sinuata (Mitt.) Buck, comb. nov. Hookeria sinuata Mitt., J. Linn. Soc., Bot. 12: 358. 1869. TYPE: ECUADOR. Andes Quitenses, Pallatanga, Spruce s.n. (HOLOTYPE:NY!). Thamniopsis terrestris (Mitt.) Buck, comb. nov. Hookeria terrestris Mitt., J. Linn. Soc., Bot. 12: 356. 1869. TYPE: PERU. Monte Guayrapurina, Spruce 676 (HOLOTYPE:NY!). Thamniopsis undata (Hedw.) Buck, comb. nov. Leskea undata Hedw., Sp. Musc. 214. 1801. TYPE: JAMAICA. Swartz s.n. (ISOTYPE:NY!). Hookeria crispa C. M011., Bot. Zeitung (Berlin) 13: 768. 1855, syn. nov. TYPE: VENEZUELA. 1845, Moritz s.n. (LECTOTVPE--designated here: BM!). Hookeria acicularis Mitt., J. Linn. Soc., Bot. 12: 354. 1869, syn. nov. TYPE: JAMAICA. s.d., s.coll. (HOLOTYPE"NY!). Hookeria undatula C. M011., Nuovo Giorn. Bot. Ital. n.s. 4: 131. 1897, syn. nov. TYPE: BOLIVIA. Prope Yungas, 1885, Rushy s.n. (LECTOTVPE--designated here: NY!). Thamniopsis utacamundiana (Mont.) Buck, comb. nov. Hookeria utacamundiana Mont., Ann. Sci. Nat. Bot. s6r. 2, 17: 247. 1842. TYPE: INDIA. Montibus Nilgheriensibus, prope Ootacamund, Perrottet s.n. (ISOTYPE:NY!). Lepidopilum macropus Bosch & Lac., Bryol. Jav. 2: 41. 1862, prob. syn. TYPE: INDONESIA. JAVA: Monte Oengarang, Junghuhn s.n. (ISOTYPE:NY!). Hookeria purpurea C. M011., Flora 82: 459. 1896, prob. syn. TYPE: UNITED STATES. HAWAII: Hillebrand s.n. (n.v., but this is the only species in the group in Hawaii). Thamniopsis versicolor (Mitt.) Buck, comb. nov. Lepidopilum versicolor Mitt., J. Linn. Soc., Bot. 7:159. 1864; Hookeriopsis mittenii P.-Varde, Arch. Bot. Bull. Mens. 1(7): 139. 1927, non H. versicolor (Besch.)Jaeg. (I 877). TYPE: FERNANDO PO. Mann s . n . (HOLOTYPE:NY!). TRACHYXIPHIUM B u c k Traehyxiphium Buck, gen. nov. Thamniopse alfine, a quo plantis minoribus, caulibus plerumque sine hyalodermide, foliis flaccidis immarginatis acuminatis, marginibus dentibus tumidis bifidis, costa valida apicem versus dentibus geminis vel bifidis provisa, areolatione homogenea et cellulis prorulosis differt. TYPE: T r a c h y x i p h i u m g u a d a l u p e n s e ( B f i d . ) B u c k . 220 BRITTONIA [VOL. 39 Trachyxiphium aduncum ( M i t t . ) B u c k , c o m b . n o v . Hookeria adunca Mitt., J. Linn. Soc., Bot. 12: 362. 1869. TYPE: PERU. Tarapoto, Spruce 650 (HOLOTYPE:NY!). Hookeria asprella Harnpe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjabenhavn ser. 3, 9-10: 266. 1878, syn. nov. TYPE: BRAZIL. Rio de Janeiro, Glaziou 9081, 9082, 9085 (LE~rOTVPE-designated here: 9085, BM!; ISOLECTOTYPE:NY!)." Traehyxi0hium guadalupense (Brid.) Buck, comb. nov. Hypnum guadalupense Spreng. ex Brid., Muscol. Recent. Suppl. 2:96.1812. TYPE:GUADELOUPE. Ex herb. Candolle, s.coll. (HOLOTYPE:B!). Hookeriafalcata Hook., Musci Exot. 1: 54. 1818, syn. nov. TYPE: COLOMBIA. Inter Almaguer et Pasta, Humboldt & Bonpland s.n. (ISOTYPE:NY!). Hookeria repens Hook. &Grev., Edinburgh J. Sci.-2: 231. 1825. TYPE: ST. VINCENT. Guilding s.n. (ISOTYPE NY!). Hookeria velutina Hampe, Linnaea 31: 528. 1862, prob. syn. TYPE: COLOMBIA. Cipac6n, Aug 1861, Lindig s.n. (HOLOTYPE:BM!; prob. ISOTYPE:NY!). Hookeria gracilis Mitt., J. Linn. Soc., Bot. 12: 360. 1869, syn. nov. TYPE: ECUADOR. Andes Quitenses, Jameson s.n.; Canelos, Spruce s.n. (LECTOTYPE--designated here: Spruce, NY!). Hookeria guadalupensis Par. longifolia Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 237. 1876. TYPE: MARTINIQUE. Hahn 712 (HOLOTYPE:BM!). Hookeria hypniformis Bescb., Ann. Sci. Nat. Bot. s6r. 6, 3: 237. 1876, syn. nov. TYPE: GUADELOUPE. L'Herminier 45 (HOLOTYPE:BM!). Hookeria tufa Schimp. ex Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 236. 1876, syn. nov. TYPE: GUADELOUPE. Houelmont, Morne de la Decouverte, Husnot 176 (ISOTYPE:NY!). Hookeria versicolor Schimp. ex Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 238. 1876. TYPE: GUADELOUPE. L'Herminier s.n. (HOLOTYPE:BM!). Hookeriafalcatula Schimp. ex Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 237. 1876, syn. nov. TYPE: GUADELOUPE. L'Herminier s.n. (HOLOTYPE:BM!). Hookeria harrisii C. M011., Bull. Herb. Boissier 5:564.1897, syn. nov. TYPE: JAMAICA. Newhaven Pass, Harris 11015 (ISOTYPE:NY!). Hookeria dimorpha C. M011., Bull. Herb. Boissier 5: 564. 1897, syn. nov. TYPE: JAMAICA. Newhaven Pass, Harris 10097 (ISOTYPE:NY!). Trachyxiphium heteroieum (Card.) Buck, comb. nov. Hookeriopsis heteroica Card., Rev. Bryol. 37:51. 1910.TYPE: MEXICO. VERACRUZ:Jalapa, Pringle 15145 (ISOTYPE:NY!). T r a c h y x i p h i u m h y p n a c e u m (C. M i i l l . ) B u c k , c o m b . n o v . Hookeria hypnacea C. M011., Bot. Zeitung (Berlin) 14: 421. 1856. TYPE: BRAZIL. Santa Catharina, Pabst s.n. (LECTOTYVE--designated here: BM!). Hookeria subaurescens Geh. & Hampe ex Geh., Flora 64:411. 1881, prob. syn. TYPE: BRAZIL. S~O PAULO:Apiahy, Puiggari 641 b (HOLOTYPE;BM!). T r a c h y x i p h i u m p e r n u t a n s (C. M i i l l . ) B u c k , c o m b . n o v . Hookeria pernutans C. Miill., Linnaea 42: 496. 1879. TYPE: VENEZUELA. Fendler 127 (ISOTYPES: BM!, NY!). Trachyxiphium subfalcatum (Hampe) Buck, comb. nov. Hookeria subfalcata Hampe, Ann. Sci. Nat. Bot. s6r. 5, 5: 305. 1866. TYPE: COLOMBIA. Bogatfi, Tequeudama, Lindig [2150] (ISOTYPE:NY!). Hookeria curvifolia Mitt., J. Linn. Sac., Bot. 12: 362. 1869, syn. nov. TYPES: ECUADOR. Andes Quitenses, Penipe, Spruce 675; Tungnragua, Spruce 674 (SYNTYPES:Both NY!). Hookeria scabrella Mitt., J. Linn. Sac., Bot. 12: 362. 1869, syn. nov. TYPE: ECUADOR. Andes Quitenses, Tunguragua, Spruce 658 (HOLOTYPE:NY!). Hookeria viridissima Mitt., J. Linn. Soc., Bot. 12: 362. 1869, syn. nov. TYPE: COLOMBIA. Magdalena, Weir 381 (HOLOTYPE:NY!). Trachyxiphium tenue (Mitt.) Buck, comb. nov. Hookeria tenuis Mitt., J. Linn. Soc., Bot. 12: 355. 1869. TYPE: PERU: Campana, Spruce 367; Tarapoto, Spruce 638; Guayrapurina, Spruce 639; Huallaga, Spruce 640; Shillicaia, Spruce 641 (LECTOXVPE--designated here: 641 NY!). Hookeriopsis longiseta Williams, Bull. New York Bot. Gard. 6: 246. 1910, prob. syn. TYPE: BOLIVIA. Between San Jos6 and Apalo, Williams 2042 (HOLOTYPE:NY!). 1987] BUCK: HOOKERIALES 221 Trachyxiphium vagum (Mitt.) Buck, c o m b . n o v . Hookeria vaga Mitt., J. Linn. Soc., Bot. 12: 266. 1869. TYPE:ECUADOR. Andes Quitenses, Jameson [178] (HOLOTYPE:NY!). Hookeriopsis cubensis Th6r., Mern. Soc. Cub. Hist. Nat. "Felipe Poey" 14: 368. 1940, syn. nov. TYPE: CUBA. Sierra Maestra, La Bayamesa, Ekman 7187 p.p.; Pico Turquino, Ekman 5470 (LECTOTVPE--designatedhere: 5470, S (n.y.); ISOLECTOTYPES:FH!, NY!). Trachyxiphium v a r i a b l e (Mitt.) Buck, c o m b . n o v . Hookeria variabilis Hornsch. ex Mitt., J. Linn. Soc., Bot. 12: 359. 1869. TYPE:COLOMBIA. Andes Bogotenses, Weir 149. BRAZIL:Sierra dos Orgaos, Beyrich s. n.; Rio de Janeiro, Gardner s. n.; Ohla de Agua, Weir s.n. (LEC'roTYPE--designatedhere: Gardner s.n. NY!). Hookeria planiuscula Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn ser. 3, 6: 161.1875, syn. nov. TYPE:BRAZIL. Rio de Janeiro, Glaziou 7152, 7164 (LEC'rOTYPE--designated here: 7152, BM!; ISOLECTOTYPE:NY!). Hookeria tenera Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn ser. 3, 6:161. 1875, syn. nov. TYPE: BRAZIL. Rio de Janeiro, Glaziou 6354 p.p. (HOLOTVPE:BM!). A few species s t u d i e d d i d n o t b e l o n g i n a n y o f the segregate g e n e r a o f H o o k eriopsis. T h e s e are t r e a t e d as follows: I s o p t e r y g i u m p l u m i c a u l e (C. Miill.) Buck, c o m b . n o v . Hookeria plumicaulis C. Miill., Linnaea 42: 496. 1879. TYPE:VENEZUELA. Fendler 129 (ISOTYPE: NY!). Schizomitrium e i r r h o s u m ( H a m p e ) Buck, c o m b . n o v . Hookeria cirrhosa Hampe, Vidensk. Meddet. Dansk Naturhist. Foren. Kjobenhavn set. 3, 6: 162. 1875. TYPE:BRAZIL. Rio de Janeiro, Glaziou 7164 (HOLOTYPE"BM!; ISOTYPE:NY!). Schizomitrium subseeundum (Mitt.) Buck, c o m b . n o v . Hookeria subsecunda Mitt., J. Linn. Soc., Bot. 12: 358. 1869. TVPE:ECUADOR. Andes Quitenses, Tunguragua, Spruce 649 (HOLOTYPE:NY!). Schizomitrium B.S.G. T h e g e n u s S c h i z o m i t r i u m has b e e n u s e d i n r e c e n t years to r e p l a c e the later s y n o n y m Callicostella (C. M ~ i l l . ) M i t t . ( C r o s b y , 1975). I n c o n f o r m i t y w i t h this usage, the f o l l o w i n g t r a n s f e r is necesary: Schizomitrium belangerianum (Besch.) Buck, c o m b . n o v . Hookeria belangeriana Besch., Ann. Sci. Nat. Bot. s6r. 6, 3" 233. 1876. TYPE: MARTINIQUE. B~langer 489 (HOLOTYPE:BM!; ISOTYPE:NY!). Hookeria herminieri Schimp. ex Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 233. 1876, syn. nov. TYPE: GUADELOUPE. L'Herminier s.n. (HOLOTYPE:BM!). Hookeria herminieri var. rubella Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 233. 1876, syn. nov. TYPE: GUADELOUPE. L'Herminier s.n. (HOLOTYPE:BM!). Hookeria depressula C. Mtill. e• Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 233. 1876, hom. illeg., non C. Miill. (1874). Callicostella depressula Jaeg., Ber. T~itigk. St. Gallischcn Naturwiss. Ges. 18751876: 352. 1877, syn. nov. TYPE:GUADELOUPE. Duchassaing s.n. (HOLOTYPE:BM!). Hookeria hahniana Besch., Ann. Sci. Nat. Bot. s6r. 6, 3: 234. 1876, syn. nov. TYPE:GUADELOUPE. L'Herminier s.n.; MARTINIQUE.Hahn 712 p.p. (LECTOTVPE--designatedhere: L'Herminier, BM!). S c h i z o m i t r i u m b e l a n g e r i a n u m has m o s t r e c e n t l y (Welch, 1976) b e e n s y n o n y m i z e d with S. d e p r e s s u m (Hedw.) B u c k & Steere. H o w e v e r , i n S. d e p r e s s u m the leaf apex is a b r u p t l y t a p e r e d a n d the costal apices h a v e a c l u s t e r o f 3 - 6 t e e t h o n t h e m . I n c o n t r a s t , S. b e l a n g e r i a n u m h a s g r a d u a l l y a c u m i n a t e l e a v e s a n d the costal apex has (0) 1-2 teeth. Schizomitrium pallidum (Hornsch.) C r u m & Anders., a widespread tropical A m e r i c a n species, has long b e e n c o n s i d e r e d to h a v e a p a p i l l o s e seta. H o w e v e r , o n the basis o f h a b i t a t p r e f e r e n c e a n d l e a f m o r p h o l o g y , s m o o t h - s e t a e d p l a n t s m u s t be i n c l u d e d in the c o n c e p t o f the species. T o assign these c o l l e c t i o n s to S. de- 222 BRITTONIA [VOL. 39 pressum solely on the basis of seta ornamentation, as Welch (1976) did, is surely an error. Schizomitrium pallidurn, whether the seta is rough or smooth, has regularly serrate leaf margins and usually occurs on soil or rock. In contrast, S. depressum has irregularly serrate margins and grows on rotten wood. Also, the papillae o f those collections of S. pallidum with roughened setae are low and broad, not at all conspicuous like those on the setae of S. rivulare (Mitt.) Crum. Indeed, some collections can be found in which the papillae are very inconspicuous on some setae and absent on others of the same population. Aquatic Cyclodictyon Mitt. and Lepidopilum (Brid.) Brid. Although Cycloclictyon appears to be isolated in the Callicostaceae because of its well defined leaf border, its aquatic species approach the more gradually bordered (and sometimes aquatic) species of Lepidopilum. These two genera are usually distinct, but as in many other genera, aquatic species are atypical and problematic in placement. This problem is compounded because the aquatic species are rarely fertile (even if autoicous) and therefore sporophytic features are often unavailable. In this particular instance, additional complications have arisen because o f the misinterpretation, and subsequent misuse, of some epithets. In an effort to sort this out, all appropriate types were examined as well as numerous specimens from the West Indies, Central and South America. All the species included tend to have contorted and bordered leaves with relatively short cells. However, in Cyclodictyon the border remains strong from the leaf apex to the base, whereas in Lepidopilum it becomes weaker below. Also, in Cyclodictyon the costa is consistently stronger than in Lepidopilum. Therefore, the following transfer is proposed, even though the plants have never been found fertile: Cyclodictyon subtortifolium (Bartr.) Buck, comb. nov. Lepidopilum subtortifolium Bartr., Bryologist 4 9 : 1 1 9 . 1946. TYPE: GUATEMALA. DPTO. SAN MARCOS: Along road between San Sebastifin and San Mareos, Steyermark 35714 (HOLOTYPE: FH!). Arnblytropis denticulata ThOr., Mem. Soc. Cub. Hist. Nat. "Felipe Poey" 14: 367. 1940, syn. nov., non Cyclodictyon denticulatum Kuntze (1891). TYPE: CUBA. Pico Turquino, Acufza 391 (mOTYPE: NY!). A mblytropis pocsii Duarte, Acta Bot. Cubana 13: 1. 1982, syn. nov. TYPE: CUBA. Pico La Bayamesa, T. P6r 9066/CC (~-Duarte 3743) (HOLOTYPE: HAC!; ISOTYPE: NY!). In addition to the leaves strongly bordered to the base, C. subtortifoliurn is characterized by the leaf apex acute to apiculate and composed only of border cells; the laminal cells are only 1 1-15 um wide. The other aquatic Cyr is: CYCLODICTYON RORIDUM (Hampe) Kuntze Hookeria rorida Hampe, Linnaea 32: 155. 1863; Cyclodictyon roridurn (Hampe) Kuntze, Revis. Gen. PI. 2: 835. 1891. TYPE: COLOMBIA. Bogotfi Boquer6n, 2800 m, Lindig 59 (HOLOTYPE: BM!). Hookeria capillata Mitt., J. Linn. Soc., Bot. 12:341. 1869; Cydodietyon eapillaturn (Mitt.) Kuntze, Revis. Gen. P1.2: 835. 1891, syn. nov. TYPES: ECUADOR. Tunguragua, Mapa-yacu, Spruce 580, 581. COLOMBIA. Bogotfi Boquer6n, Weir 331, 337, 367 (LECTOTVPE--designated here: Weir 331, NY!). Hookeria obliquieuspis C. Miill., Bull. Herb. Boissier 5: 564. 1897; Cyclodietyon obliquieuspis (C. Miill.) Crum & Barlr., Bull. Inst. Jamaica, Sci. Ser. 8: 50. 1958, syn. nov. TYPE: JAMAICA. Newhaven Pass, Harris 10097 (ISOTVPE: NY!). Cyclodictyon roridum is characterized by its long, slenderly acuminate leaf apex and small laminal cells. It most often grows on moist humus rather than in truly aquatic situations. The other species involved in the confusion is truly a Lepidopilum, as evidenced by the peristome in the type collection. 1987] BUCK" HOOKERIALES 223 LEPIDOPILUM TORTIFOLIUM M i t t . Lepidopilum tortifolium Mitt., J. Linn. Soc., Bot. 12: 374. 1869. TYPE: COLOMBIA. Andes Bogotenses, prope Bucaramanga, Weir 147. ECUADOR. Andes Quitenses, ft. Bombonasa, Spruce 783 (LECTOTVPE--designatedhere: NY!). Hookeria riparia Mitt., J. Linn. Soc., Bot. 12: 345. 1869; Cyclodictyon riparium (Mitt.) Kuntze, Revis, Gen. P1. 2: 835. 1891, syn. nov. TYPE: ECUADOR. Andes Quitenses, ft. Bombonasa, Spruce 593 (HOLOTYPE:NY!). L i k e Cyclodictyon subtortifolium, t h e l e a v e s in L. tortifolium (as t h e n a m e i m plies) are c o n t o r t e d . H o w e v e r , in L. tortifolium t h e b o r d e r a t t h e l e a f b a s e is i n d i s t i n c t b e c a u s e all b a s a l cells a r e e l o n g a t e , a n d the large l a m i n a l cells ( 2 8 - 3 3 ~tm wide) e x t e n d i n t o t h e a c u m e n . It differs f r o m C. roridum in t h e s h o r t e r l e a f a p e x a n d larger l e a f cells. Calyptrochaeta Desv. F o r n o m e n c l a t u r a l r e a s o n s , Eriopus B r i d . h a s t o b e r e p l a c e d b y Calyptrochaeta. A n u m b e r o f t h e c o m b i n a t i o n s i n t o Calyptrochaeta h a v e b e e n m a d e , b u t m a n y m o r e a w a i t s t u d y b e f o r e t h e i r t r a n s f e r is a p p r o p r i a t e . A c o u p l e o f t h e s e c o m b i nations, pertinent to my work, are made here. Calyptrochaeta setigera ( M i t t . ) Buck, c o m b . n o v . Eriopus setigerus Mitt., J. Linn. Soc., Bot. 12: 392. 1869. TYPE: BRAZIL. Inter Santos et S. Paulo, prope Rio Grande, Weir 6 (HOLOTYPE:NY[). Calyptrochaeta albescens ( H a m p e ) B u c k , c o m b . n o v . Lepidopilum albescens Hampe, Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn ser. 3, 910: 265. 1878. TYPE: BRAZIL. Rio de Janeiro, Glaziou 9096 (ISOTYPE:NY[). Acknowledgments A p p r e c i a t i o n is e x t e n d e d to W . C. Steere, H o w a r d C r u m , D a n a Griffin, B r u c e A l l e n , S t e v e n C h u r c h i l l , a n d J o s e p h R o h r e r for t h o u g h t f u l d i s c u s s i o n . R u p e r t Barneby once again tamed my aberrant Latin. The National Science Foundation is g r a t e f u l l y a c k n o w l e d g e d for t h e i r s u p p o r t o f t h i s w o r k t h r o u g h g r a n t B S R 8 0 2 1 7 2 9 . S p e c i a l t h a n k s go to A l a n H a r r i n g t o n for his g e n e r o u s a s s i s t a n c e w h i l e I v i s i t e d t h e B r i t i s h M u s e u m . T h e c u r a t o r s o f B, F H , a n d C A N M a r e a l s o t h a n k e d for t h e l o a n o f m a t e r i a l . Literature Cited Allen, B. H., R. E. Magill & M. R. Crosby. 1985. Observations on the peristome and systematic position of Tetrastichium fontanurn (Musci). J. Bryol. 13:515-522. Basile, D. V. & M. R. Basile. 1984. Probing the evolutionary history ofbryophytes experimentally. J. Hattori Bot. Lab. 55: 173-185. Bescherelle, I~. 1876. Florule bryologique des Antilles fran~aises. Ann. Sci. Nat. Bot. srr. 6, 3: 175265. Brotherus, V. F. 1925. Hookeriales. In: A. Engler & K. Prantl, Die natiidichen Pflanzenfamilien, ed. 2, l l : 214-278. Buck, W . R . & D . H . Vitt. 1986. Suggestions for a new familial classification ofpleurocarpous mosses. Taxon 35: 21-60. Crosby, M.R. 1969. A revision of the tropical American moss genus Pilotrichum. Bryologist 72: 275-343. 1974. Toward a revised classification of the Hookeriaceae (Musci). J. Hattori Bot. Lab. 38: 129-141. 1975. Lectotypification of Schizomitrium B.S.G. (Musci, Hookeriaceae). Taxon 24: 353355. - & B. H. Allen. 1985. Brymela tutezona (Musci: Hookeriaceae), a new genus and species from 224 BRITTONIA [VOL. 39 western Panama. In: Contributions to systematic bryology dedicated to Lewis E. Anderson. Monogr. Syst. Bot. Missouri Bot. Gard. 11: 211-216. - & R. E. Magill. 1985. A review of the moss genus Hypnella. Bryologist 88: 121-129. Crum,'H. 1984. Notes on tropical American mosses. Bryologist 87: 203-216. 1985. A new genus of Hookeriaceae from Mexico. Bryologist 88: 23-24. K/Sck, C. 1939. FossileKryptogamenausdereoz~inenBraunkohledesGeiseltales. NovaActaLeop. n.s. 6: 333-359, Tar. 37-45. Miller, H.A. 1971. An overview of the Hookeriales. Phytologia 21: 243-252. Welch, W. H. 1976. Hookeriaeeae. N. Amer. F1. II, 9: 1-133. BOOK REVIEW a n d the W o r l d ' s Food. By D o n a l d J. Plucknett, Nigel J. H. Smith, Gene B a n k s J. T. Williams, and N. M u r t h i Anishetty. Princeton U n i v e r s i t y Press, Princeton, N J 08540. I S B N 0-691-08438-6. 1987. 247 pp. $35 (cloth). This b o o k , which is a p p r o p r i a t e l y dedicated to Nikolai Vavilov, is an excellent review o f the current world situation o f the collection a n d storage o f germ p l a s m o f food crops. The c o m b i n e d experience o f the four authors provides a t h o r o u g h coverage o f m a n y aspects o f the p r o b l e m s that face the future o f agriculture in the world. T h e topics c o v e r e d v a r y f r o m a discussion o f historic collectors o f living plant material to the use o f biotechnology a n d tissue storage. Botanists will especially enjoy reading the chapters on plant collectors a n d gene b a n k s a n d on wild species. In the latter chapter a strong case is m a d e for the need to preserve wider gene pools o f food plants f r o m their wild relatives. M a n y good e x a m p l e s o f the use o f genes f r o m wild species to incorporate disease resistance a n d forest tolerance into crops are given, such as the use o f M a n i h o t glaziovii for resistance against cassava mosaic disease and o f Solanum megistacrolobum to p r o d u c e a frost resistant potato. The e x a m p l e s given p r o v i d e a strong case for the vital i m p o r t a n c e o f wild species, yet t o d a y these species account for less t h a n two percent o f gene b a n k accessions and only wild relatives o f wheat, potato, t o m a t o , and corn h a v e been extensively collected for gene banks. This t h e m e is repeated in different ways in several chapters such as the one on sources o f seeds for the future. A good balance is m a i n t a i n e d between what we can learn f r o m history, the present situation, and the future needs. T h e r e is a fascinating case study o f the d e v e l o p m e n t o f the rice variety I R 3 6 f r o m cultivated and wild rice stocks. Thirteen rice varieties f r o m six countries and a wild species were used to p r o d u c e IR36, which is now the m o s t widely planted variety o f rice in the world. T h i s b o o k will be an invaluable aid to e c o n o m i c b o t a n y courses that deal with the m a j o r food crops. A useful a p p e n d i x provides the m e a n i n g o f the a c r o n y m s o f the n u m e r o u s institutions that are i n v o l v e d in the distribution and storage o f germ plasm. A c r o n y m s such as I B P G R (International B o a r d for Plant G e n e t i c Resources), C I M M Y T (Centro N a c i o n a l de M e j o r i m e n t o de Maiz y Trigo), a n d C E N A R G E N (Centro N a c i o n a l de Recursos Gen&icos) are thrown a r o u n d liberally b y those i n v o l v e d in international germ p l a s m work. The b o o k is well indexed a n d cites a large n u m b e r o f references. Systematists will like the strong support given for the value o f botanic gardens, herbaria, a n d systematic research on page 91. T h e reading o f this well-written a n d b r o a d review leaves the reader rather depressed a b o u t the current world situation regarding crop germ p l a s m a n d aware o f the need to actively p r o m o t e the p r e s e r v a t i o n o f the plant genetic resources o f the world. -- GHILLEAN T. PRANCE, N e w Y o r k Botanical Garden.