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.