An upright, glabrous, emergent or submerged herb. Leaves broadly lanceolate-ovate, (3.5-) 6-9 (-12) cm long, (1.5-) 2.5-3.8 (-5) cm broad, rounded or slightly cordate at the base, acute-acuminate; petiole cylindrical, 7-30 cm long. Panicle of 4-8 suberect branches and pedicels per whorl, 50-55 cm long. Flowers white or pale pink; c. 1 cm across; pedicels filiform, 1-2.5 (-3) cm long, bracts linear-lanceolate, those of the lower whorls longer, gradually becoming smaller in upper ones, acuminate. Sepals elliptic-ovate, c. 3 mm long, c. 2 mm broad, somewhat hooded, membranous-margined. Petals oblong, almost double the size of sepals, claw yellow, limb white or pale-pink. Stamens with c. 1.5-2 mm long filaments, anthers yellow, oblong. Ovaries ovate, c. 1 mm long; styles longer than ovaries. Achenes oblong-obovoid, c. 2-3 mm long, with 1-2 grooves on back, pale brown.
Fl. Per.: June-August.
Type: Described from Europe, Herb. Linn. 473.1 (LINN).
Distribution: West Pakistan, India, Burma, Russia, Europe, north and tropical Africa.
Common in ditches, ponds and along borders of rice fields in North Western Frontier Province and Kashmir.
Root powder has been used as a cure for hydrophobia. Acid extract administered for treatment of tetanus, rabies and mammary congestions resulted in complete paralysis of the patient. Fresh leaves are used in homoeopathy. The starch rich rootstock is eaten elsewhere but not in Pakistan.