Perennial aquatic herbs; stems creeping and rooting at nodes. Leaves submerged and linear or floating and ovate to reniform or borne on long petioles. Flowers small, in spikes or solitary. Perianth nearly actinomorphic, divided into 6 equal or subequal lobes. Stamens 3, exserted, unequal. Ovule 1-locular or imperfectly 3-locular; ovules numerous. Capsule oblong or linear. Seeds longitudinally ribbed. Worldwide: c. 10 species, 1 native to tropical Africa, the rest occurring in tropical and subtropical America Caprivi: 1 cultivated taxon. |