|Abstract||Glabrous, annual or perennial herbs. Leaves distichous, radical, entire, linear, with a sheath. Inflorescence terminal, spicate or racemose. Flowers bisexual, actinomorphic, small, inconspicuous, mostly green. Perianth segments 6, conchiform. Stamens 6 (or partly reduced), epi-tepalous. Anthers sessile, extrorse, cells 2. Carpels 6, or less by abortion, free or united, or partly free; ovule 1 per cell, basal, erect; style mostly absent. Pericarp dry. Seed exalbuminous, embryo straight.|
Distr. Cosmopolitan, the majority of the ca 15 spp. known from the S. hemisphere. The Malaysian species is the only one of subg. Cycnogeton (ENDL.) BUCH., distinct by entirely free carpels.