Aquatic, floating herb, long, slender petioles like branches reaching the surface of water, producing a node from which starts a tuft of roots and a cluster of flowers; a single floating leaf and a single branch which again proceeds in same manner; leaves orbicular to oblong, deeply cordate with an acute sinus, wavy margins, fleshy, smooth above verrucose beneath; flowers white, fascicled at nodes, borne on slender pedicels in clusters, at the base of petiole; calyx segments 4-5, glabrous, narrowly lanceolate or oblong, slightly connate at base, imbricate, persistent; corolla white with yellow base, rotate, lobes linear-oblong, connate at base, valvate; stamens epipetalous, anthers diathecous; disc of 5 nectariferous glands alternating with stamens; ovary bicarpellary syncarpous, superior ovary, style simple,stigma 2-3 fid; fruit capsule, ovoid or oblong, indehiscent, 5-10 seeded; seeds numerous, small, lenticular, scabrous.