Latinised form of the Malabar name.

Annual or perennial aquatic plants. Leaves basal, submerged, floating or emergent, usually divided into blade and sheathed stalk except when young. Flowers unisexual, on the same or different plants and sexes sometimes both within the same spathe. Female and bisexual spathes 1-flowered. Male spathes many-flowered. Perianth of 2 whorls, the innermost largest. Stamens 6-15. Ovary 6-chambered. Fruit an indehiscent utricle containing numerous seeds.

Seed.

21species from tropical and warm temperate regions. 2 Australian native species.

O. alismoides is cultivated as a green vegetable in Malaysia.

Stolons absent; leaves floating or emergent, basal and mostly differentiated into blade and stalk.

Cook (1984).

Source: Spencer, R. (2005). Hydrocharitaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.