''Alisma'' is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of

aquatic plant Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...

s with

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

either floating or submerged, found in a variety of still water habitats around the world (nearly worldwide).Kew World Checklist of Selected Plant Families
/ref> The flowers are

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

, and are arranged in

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

raceme A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...

s, or umbels. ''Alisma'' flowers have six

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s, numerous free carpels in a single whorl, each with 1 ovule, and subventral styles. The fruit is an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

with a short beak. The nineteenth century British art and social critic John Ruskin believed that the particular curve of the leaf-ribs of ''Alisma'' represented a model of '

divine proportion In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. Expressed algebraically, for quantities a and b with a > b > 0, where the Greek letter phi ( ...

' and helped shape his theory of Gothic architecture.J. Mordaunt Crook, "Ruskinian Gothic" in The Ruskin Polygon: Essays on the Imagination of John Ruskin ed. John Dixon Hunt and Faith M. Holland (Manchester University Press, 1982) pp. 65–93. ''Copóg Phádraig'' ("Patrick's leaf") is the Irish name for the water-plantain. It is reputed to ward off fairies. Water plantains are perennial plants. These herbs are usually emergent plants high. They have broad leaves that can be either tapered or rounded at the base. When submerged, the plant produces ribbon-like leaves. Inflorescences are highly branched. They produce

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral d ...

of perfect flowers either white or pinkish. The fruits are flat-sided nutlets in length. These herbs usually flower in late May to early September, but this can vary with conditions.Gleason and Cronquist (1991); Fernald (1970); Voss (1972). Water-plantains are wetland plants and found in saturated soils and shallow water as well as marshes, wooded

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s, shrub swamps and flooded farmland. When introduced to an area, water plantain can rapidly reproduce.

Species and subspecies

The following taxa are recognized as of May 2014: *''

Alisma × bjoerkqvistii ''Alisma'' is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of aquatic plants with leaves either floating or submerged, found in a variety of still water habit ...

'' Tzvelev - Russia * ''

Alisma canaliculatum ''Alisma canaliculatum'', commonly known as channelled water plantain, is a species of plants in the Alismataceae. It is native to Japan, Korea, the Ryukyu Islands, Taiwan, the Kuril Islands, and China (Anhui, Fujian, Guizhou, Henan, Hubei, Hunan ...

'' A.Braun & C.D.Bouché - eastern Asia * ''

Alisma gramineum ''Alisma gramineum'' is a small aquatic plant in the water-plantain family. It has several common names including narrowleaf water-plantain, ribbonleaf water-plantain or ribbon-leaved water-plantain, and grass-leaved water-plantain. It grows in m ...

'' Lej. - Europe, Asia, North Africa; minor naturalization in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

*''

Alisma × juzepczukii ''Alisma'' is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of aquatic plants with leaves either floating or submerged, found in a variety of still water hab ...

'' Tzvelev - Russia * ''

Alisma lanceolatum ''Alisma lanceolatum'' is a species of aquatic plant in the water plantain family known by the common names lanceleaf water plantain and narrow-leaved water plantain. It is widespread across Europe, North Africa and temperate Asia. It is natural ...

Withering William Withering FRS (17 March 1741 – 6 October 1799) was an English botanist, geologist, chemist, physician and first systematic investigator of the bioactivity of digitalis. Withering was born in Wellington, Shropshire, the son of a surg ...

- Europe, Asia, North Africa; naturalized in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, New Zealand, California etc. * ''

Alisma nanum ''Alisma nanum'' is a species of plant in the Alismataceae. It is endemic to Xinjiang in western China, where it grows in marshes at elevations of about 600 m.Cui, Da-fang. 1992. Bulletin of Botanical Research, Harbin 12(4): 369–371, f. 1 Ref ...

'' D.F.Cui - Xinjiang * ''

Alisma orientale ''Alisma orientale'', commonly known as Asian water plantain is a flowering plant species in the genus ''Alisma'' found in Asia. ''Alisma orientale'' is sometimes treated as a variety of ''Alisma plantago-aquatica'' (''Alisma plantago-aquatica'' ...

'' * '' Alisma plantago-aquatica'' L. - Europe, Asia, Africa **''Alisma plantago-aquatica'' subsp. ''orientale'' (Sam.) Sam. **''Alisma plantago-aquatica'' subsp. ''plantago-aquatica'' *'' Alisma × rhicnocarpum'' Schotsman - western Europe * ''

Alisma subcordatum ''Alisma subcordatum'', the American water plantain, is a perennial aquatic plant in the water-plantain family (Alismataceae). This plant grows to about 3 feet (1 meter) in height with lance to oval shaped leaves rising from bulbous corms with ...

'' Raf. eastern

* ''

Alisma triviale ''Alisma triviale'', the northern water plantain, is a perennial semi- aquatic or aquatic plant in the water-plantain family (Alismataceae). Description It is a perennial herb that ranges in height from 1-3 ft. Each plant has long-petioled, l ...

'' Pursh -

* ''

Alisma wahlenbergii ''Alisma wahlenbergii'', the Baltic water-plantain, is a species of plant in the family Alismataceae. It is native to the area around the northern Baltic Sea: Finland, Sweden, Estonia, Latvia, Lithuania, and northern and northwestern Russia. ' ...

'' ( Holmb.) Juz. Baltic Sea region

References

External links

{{Taxonbar, from=Q157350 Alismataceae genera Freshwater plants Taxa named by Carl Linnaeus