Floating leaves 3-5 x 3.5-7 cm, entire at the basal end, dentate to crenate at the apical end, glabrous above, densely pubescent-villous below; stipules c. 3 mm, linear; petiole 3-12 cm long, woolly, with a fusiform swelling at the upper end. Submerged leaves c. 5 cm, pinnatisect, segments fillform. Flower tubular, white. Pedicel 2.5-3.5 cm long, villous. Sepals 7 mm long, ovate, 2 out of 4 persistent, villous. Petals oblong with an elongated narrow base, c. 2 times the length of the sepals. Disc c. 3 mm wide, edges dissected. Style c. 4 mm long, single, tapering; stigma rounded. Nut 2-3.8 cm long and broad, quadrangular, top-shaped, beak surrounded by long stiff hairs. Fruit bihorned; horns c. 2 cm long, pointing upwards, reflexedly barbed below the tip.

Fl.Per.: July-September. Fr. September-November.

Lectotype: India, Roxburgh (BM).

Distribution: Asia and tropical Africa.

Grows in lakes and ponds and is often cultivated for its edible fruit. The peeled nut is eaten raw or cooked.