A submerged, fresh-water herb with a tuberous, subspherical, stoloniferous rootstockleaves long-petioled, 30-90cm long, oblong to linear-oblong, linear or lanceolate,apex rounded or acute, all submerged, membranous, translucent, undulate, basecuneate, 2-lobed or cordate, 5.9-veined, cross venules conspicuous, petiolescompressed shorter or longer than the blade scape-bearing one floating or emergedspike enclosed in a calyptriform, membranous sheath much longer than the leaves,terete, thickening upwards; flowers bisexual, in a solitary spike which is 7.5-12.5cmlong, rachis stout, elongating in fruiting; perianth segments 2, 0.4cm long, obovate-spathulate, much longer than the stamens, white, petaloid, caducous; stamens 6,filaments spreading, persistent, unequal, subulate. hypogynous, anthers oblong; ovarysuperior, 3-carpellary, narrowed into a very short style; fruit-follicles 6-8mm long, Ior 2.seeded, oblong, beaked, smooth.Flowers during February and May. (Sri Lanka)