Description: Erect rhizomatous aquatic perennials or annuals. Lower leaves distichous, the upper more or less spiral.
Inflorescence spicate, branched on larger plants. Flowers sessile, subtended by spathe-like bracts. Perianth yellow, hairy; outer whorl free; inner whorl fused to base of stamen. Stamen 1; anther twisted at dehiscence. Ovary hairy, imperfectly 3-locular; stigma shortly 3-lobed.
Fruit a 3-valved capsule. Seeds ovoid, striate, numerous.
Distribution and occurrence: World: 1 species, Australia to South-East Asia, Japan. Australia: 1 species
Text by S. W. L. Jacobs