Alismataceae

Taxonomy

Family name: Alistmataceae Vent.

Synonym(s): Damasoniaceae Nakai; Limnocharitaceae Takht. ex Cronquist

Common name(s): water-plantain family

*Number of genera/species: 17/115

List of genera (GRIN-Global)

Disseminule

fruit (one-seeded) or seed

Description

Fruit dehiscent, folliclefollicle:
a dry to (rarely) fleshy fruit derived from a single carpel that opens along a single longitudinal suture; the seeds may be arillate or with a fleshy testa
(Butomopsis, Hydrocleys and Limnocharis) or aggregateaggregate:
fruit formed from a single flower with carpels several and distinct
of folliclesfollicles:
a dry to (rarely) fleshy fruit derived from a single carpel that opens along a single longitudinal suture; the seeds may be arillate or with a fleshy testa
(Damasonium), or indehiscentindehiscent:
not opening on its own, as in a fruit
, acheneachene:
a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point
, 0.8–45 mm long, linearlinear:
(shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide
to trigonoustrigonous:
3D shape—having three faces that meet at distinct angles; triangular in outline
, compressedcompressed:
flattened; in grasses, used to denote compression (not necessarily flattened) either laterally or dorsiventrally
, tereteterete:
approximately circular in cross section; width and thickness approximately equal
, or angularangular:
2D shape—having sides that meet at acute or obtuse angles  
in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
, often beakedbeaked:
a usually firm, terminal appendage, sometimes tapered
, sometimes with one laterallateral:
(of embryo) embryo lies along the side of the seed, generally towards one end; of, at, or from the side; in grasses, can refer to the sides adjacent to the dorsal and ventral sides
wing, one (achene) to many seeded (follicle). Pericarppericarp:
fruit wall or fruit coat
yellow to black, dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
, glabrousglabrous:
without hairs
or pubescentpubescent:
surface relief—bearing hairs
, smooth, ridged, wartywarty:
surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose
, spinyspiny:
having slender, stiff, sharp projections oriented in the general plane of the structure
, ribbedribbed:
surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface
, or groovedgrooved:
surface relief—linear depressions that may be single or form a series of grooves over the surface
, sometimes glandularglandular:
surface relief—covered with small, raised secretory glands, regular or irregularly shaped, translucent or opaque, and maybe distinctly colored
. In Damasonium, 6-10 folliclesfollicles:
a dry to (rarely) fleshy fruit derived from a single carpel that opens along a single longitudinal suture; the seeds may be arillate or with a fleshy testa
are clustered and appear star-shapedstar-shaped:
(of fruit), having a distal aspect like the stylized shape of a star, usually found in aggregate versus simple fruit
at maturity but usually fall singly.

Seed variously shaped, compressedcompressed:
flattened; in grasses, used to denote compression (not necessarily flattened) either laterally or dorsiventrally
to tereteterete:
approximately circular in cross section; width and thickness approximately equal
in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
, 1–7 mm long. Seed coat brown, thinthin:
having or being of relatively little depth
, membranousmembranous:
texture—extremely thin, pliable, and fairly tough
, smooth, striate to ribbedribbed:
surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface
, wartywarty:
surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose
, or spinyspiny:
having slender, stiff, sharp projections oriented in the general plane of the structure
, sometimes glandularglandular:
surface relief—covered with small, raised secretory glands, regular or irregularly shaped, translucent or opaque, and maybe distinctly colored
. Hydrocleys seeds are sparsely to densely glandular-pubescent.

Embryo strongly curvedcurved:
(of embryo) linear embryo is curved into an arch or horseshoe with the ends far apart
to horseshoe-shapedhorseshoe-shaped:
3D shape—relatively slender and strongly compressed, the whole strongly curved over its length in a plane perpendicular to the direction of compression and forming an incomplete circle, the ends somewhat straighter than the rest and parallel or nearly so
, often visible through seed coat. Endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
lacking.

Habitat and crop association

Several species are weedy. Sagittaria sagittifolia L. is a federal noxious weed, more available on the Federal Noxious Weed Disseminules of the U.S. and Aquarium & Pond Plants of the World (APPW). APPW tool also includes descriptions and images of other species in this family, which may be encountered.

Identification features

Fruit
Type	achene, follicle
Size range	0.8–45 mm long
Shape(s)	globose, ellipsoidellipsoid: 3D shape—elliptic , ovoidovoid: 3D shape—ovate , linearlinear: (shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide , lanceoloidlanceoloid: 3D shape—lanceolate , cylindricalcylindrical: 3D shape—a cylinder, with parallel sides and a circular cross-section; tubular or rod-shaped , trigonoustrigonous: 3D shape—having three faces that meet at distinct angles; triangular in outline , reniform
Texture	membranous, spongy
Surface relief	smooth or glandularglandular: surface relief—covered with small, raised secretory glands, regular or irregularly shaped, translucent or opaque, and maybe distinctly colored , ridgedridged: surface relief—raised, thick ridges, sharp edged or rounded, usually in a series that may cover the entire surface , wartywarty: surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose , spinyspiny: having slender, stiff, sharp projections oriented in the general plane of the structure , ribbedribbed: surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface , grooved
Color(s)	black, brown, yellow
Unique features	Genera can be identified based on ornamentation of pericarppericarp: fruit wall or fruit coat .
Seed
Size range	1–7 mm long
Shape(s)	curved, hippocrepiformhippocrepiform: 3D shape—horseshoe-shaped , oblongoblong: 2D shape—much longer than broad with nearly parallel sides, corners are rounded , ellipsoidellipsoid: 3D shape—elliptic , ovoidovoid: 3D shape—ovate , conicalconical: 3D shape—cone-shaped, with the point of attachment at the broad end , polygonal
Surface relief	smooth, striatestriate: surface relief—having fine, parallel lines, grooves or ridges , ridgedridged: surface relief—raised, thick ridges, sharp edged or rounded, usually in a series that may cover the entire surface , ribbedribbed: surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface , spinyspiny: having slender, stiff, sharp projections oriented in the general plane of the structure , wartywarty: surface relief—distinct, rounded projections that are large relative to the fruit size; tuberculate, verrucose , glandularglandular: surface relief—covered with small, raised secretory glands, regular or irregularly shaped, translucent or opaque, and maybe distinctly colored , sometimes pubescent
Color(s)	brown
Unique features	Seeds with strongly curvedcurved: (of embryo) linear embryo is curved into an arch or horseshoe with the ends far apart embryos visible through seed coat.
Other
Embryo	strongly curvedcurved: (of embryo) linear embryo is curved into an arch or horseshoe with the ends far apart , large
Nutritive tissuenutritive tissue: tissue within the seeds that nourishes the developing embryo; such as endosperm, perisperm, or chalazosperm in angiosperms; megagametophyte in gymnosperms	endosperm endosperm: nutritive starch- and oil-containing tissue present in many seeds lacking

Distribution

Nearly worldwide distribution. Occurs throughout most of the Americas including the West Indies, Eurasia, Africa, Indian Ocean Islands, and Australia.

Distribution map courtesy of Angiosperm Phylogeny Website.

References

Baskin and Baskin 2021Baskin and Baskin 2021:
Baskin C and Baskin J. 2021. Relationship of the lateral embryo (in grasses) to other monocot embryos: A status up-grade. Seed Science Research 31 (3): 199-210. doi:10.1017/S0960258521000209; Carter 1960Carter 1960:
Carter S. 1960. Alismataceae. In: Hubbard CE and Milne-Redhead E, eds. Flora of Tropical East Africa. Vol 4. Crown Agents for Oversea Governments and Administrations, London UK. 16 pp.; Dahlgren et al. 1985Dahlgren et al. 1985:
Dahlgren RMT, Clifford HT, and Yeo PF. 1985. The families of the monocotyledons: structure, evolution, and taxonomy. Springer-Verlag, Berlin. 520 pp.; Flora of Australia 2021+Flora of Australia 2021+:
Flora of Australia. Australian Biological Resources Study, Canberra. Accessed January-May 2021. URL: http://www.ausflora.org.au; Flora of North America Editorial Committee 1993+Flora of North America Editorial Committee 1993+:
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. Flora of North America Association, New York and Oxford. Accessed January-December 2021. URL: http://beta.floranorthamerica.org.; Kirkbride et al. 2006Kirkbride et al. 2006:
Kirkbride JH, Jr, Gunn CR, and Dallwitz MJ. 2006. Family guide for fruits and seeds, vers. 1.0. Accessed September 2020ndash;January 2022. URL: https://nt.ars-grin.gov/seedsfruits/keys/frsdfam/index.cfm .; Noxious Weed Regulations 2020Noxious Weed Regulations 2020:
Noxious Weed Regulations. 2020. 7 C.F.R. sect; 360.100-360.600.; Thiele and Adams 2014Thiele and Adams 2014:
Thiele KR and Adams LG. 2014. Families of Flowering Plants of Australia. Accessed January-December 2021. URL: https://keys.lucidcentral.org/keys/v3/FFPA/key/FFPA/Media/Html/index.htm; Zhengyi et al. 2004+Zhengyi et al. 2004+:
Zhengyi W, Raven PH, and Deyuan H. 2004+. Flora of China [online]. 25 vols. Science Press, Beijing China amp; Missouri Botanical Garden, St. Louis USA. Accessed January-December 2021. http://flora.huh.harvard.edu/china/; Zomlefer 1994Zomlefer 1994:
Zomlefer WB. 1994. Guide to Flowering Plant Families. The University of North Carolina Press, Chapel Hill. 430 pp.

*The number of genera and species is based on Christenhusz and Byng 2016Christenhusz and Byng 2016:
Christenhusz MJM and Byng JW. 2016. The number of known plant species in the world and its annual increase. Phytotaxa 261 (3): 201ndash;217. https://doi.org/10.11646/phytotaxa.261.3.1, which may differ from the number of genera in GRIN-Global.