Monoecious. Aerial leaves broadly to narrowly sagittate with 2 long acute basal lobes; floating leaves (if present) lanceolate to ovate. Flowers in racemes or panicles; at least the lower bracts free. Petals 10-15 mm, white, usually with a purple patch at the base. Filaments of stamens linear, glabrous; anthers usually purple, Fruitlets 4-6 mm, with a short, erect, apical beak.