Annual or perennial, succulent hydrophytes. Leaves upright, sagittate or cuneate at the base, glabrous or pubescent. Inflorescence upright, scapigerous raceme of 4-7 whorls of 3-flowers each. Flowers bisexual and male (plants polygamous), white, bisexual flowers towards base of raceme, male ones towards apex; bracteate. Sepals patent, reflexed after anthesis, persistent. Petals white. Stamens 6, antisepalous, filaments dilated towards the base. Carpels 15-numerous, crowded on the thalamus; ovaries ovoid; style ventral; pistillode absent in male flowers. Achenes turgid with lateral air sacs between endocarp and ridged exocarp. Seed and embryo curved, testa membranous.

1 (-3) species; distributed in the old world tropics from tropical Africa and Indo-Pakistan subcontinent to Indo-China, Java and Timor.

Some authors regard this genus as being monotypic and the rest of the described species as variants of it. However, Susan Carter reporting 2 species from East Tropical Africa (Fl. E. Trop. Afr. (Alism.) 8. 1960) remarks “the difference between (them) are constant, and too diverse to be the variations of the same species”. She regards the genus as consisting of 3 species.

Lower Taxon

• Limnophyton obtusifolium (Linn.) Miq.

Related Synonym(s):

• Alisma obtusifolium (Linn.) = Limnophyton obtusifolium (Linn.) Miq.
• Alisma sagittifolium Willd. = Limnophyton obtusifolium (Linn.) Miq.
• Sagittaria obtusifolia Linn. = Limnophyton obtusifolium (Linn.) Miq.