Fresh-water plants with 15-25 cm long stolons and fibrous roots. Leaves floating or emergent, lamina ovate-cordate to broad-ovate or suborbicular, 2-6 cm long, 2-7.5 cm broad, obtuse, entire, basally ± cordate or reniform, often truncate; petiole 3-15 cm long, thickened towards the base; stipule solitary, liguliform, 5-25 mm long, obtuse. Male spathe of 2 bracts, 10-30 mm long, on up to 25 mm long peduncle. Male flowers on 3-6 mm long pedicles; sepals oblong, 4-8 mm long, 2-5 mm wide, brownish mottled; petals 8-18 mm long, 6-9 mm wide, white with yellow claw; stamens often in 6 pairs, the antipetalous 3 pairs staminodial or with minute orange-yellow anthers, filaments dilated, yellow, ribbed. Female spathe smaller than male one. Female flower: sepals and petals as in male; staminodes opposite the sepals, free or connate; ovary oblong-elliptic, 5-6 mm long; styles bibbed, hairy. Fruit 5-10 mm long, 4-8 mm in diameter. Seeds with mucilaginous hairs, broadly ellipsoidal, 1-1.5 mm long.