Herbaceous rooted aquatic forming dense, submerged mats, upper branches with emergent leaves and flowers. Stems long, thin, rooting at lower nodes, roots long, with numerous thin rootlets. Submersed leaves thin, linear, up to 80 x 1-3 mm, sheathing at base, sheath auriculate. Floating leaves with long petiole; lamina cordate, c. 10-20 x 10-15 mm, entire, upper surface minutely pustulate. Flowers terminal, solitary, enclosed below by a tubular spathe with its short apex abruptly recurved, apiculate; perianth-tube narrowly cylindrical, up to 20 mm long; lobes spreading, narrowly ovate, c. 6 mm long; mauve or white. Stamens free. Capsule fusiÂform, attenuated into a long, persistent style, c. 15 mm long. Seeds numerous, typical. Fig. 19.
