Leiothylax

Submerged freshwater herbs; basal part thalloid, foliaceous or ribbon-like. Stems long, simple or divaricately branched. Leaves dichotomously branched, segments linear. Spathellas (spathaceous bracts) in clusters along the stems, ovoid to subspherical, rupturing irregularly at the apex at anthesis; flower inverted (reflexed) within the spathella before anthesis. Pedicel long-exserted after anthesis, bearing the flower erect. Tepals 2, minute, one on each side of the andropodium. Stamens 2(3); filaments joined for at least half their length; anthers 2-locular, introrse; pollen in monads. Ovary spherical, 1-locular with central placentation, borne on a well-developed gynophore and surmounted by 2 free styles; placentas globular, bearing many anatropous ovules. Capsule smooth, globose, dehiscing into 2 equal caducous valves. Seeds many, small, red-brown, testa reticulate.