Perennial, rhizomatous herbs, rhizome erect. Leaves all floating, oblong - orbicular with a deep basal sinus or quite entire, 5-8 (-10) x 4-7 (-8) cm, lobes acute, glabrous. Flowers white, borne on long pedicels, 3-6 cm in diameter. Receptacle strongly 4-angled. Sepals 4, obtuse, 2-3 (-3.5) x 1-125 cm, coriaceous, persistent. Petals 8-17, white elliptic, oblong 2-3 (-4) x 1-13 cm. Stamens 3-senate, anthers with very small appendages or appendages absent. Carpels usually 7-10, carpellary appendages long and white, flattened eventually concealing stigmatic surface.

Type: USSR, Lena river, Gmelin.

B-8 Dal lake, Srinagar, R. R. & I. D. Stewart 3261 (RAW), Bandapur, 5500 ft, in shallow water, J. D. Stainton 7867 (BM), lower Udder valley, 6000 ft, R. R. Stewart 8103 (RAW), C-8 Sialkot, Abdul Sattar 25 (RAW).

Distribution: North America, N. E. Europe, USSR, China, Pakistan, India and Japan.

Common in the lakes of Kashmir, in Japan the seeds and leaf buds are used as food.