Widespread in aquatic and semi-aquatic regions worldwide, but missing from Australia, New Zealand and most of South America. The starchy rhizome can be eaten and the long leaves used in matting and weaving chair bottoms.
Individuals are tall and can reproduce clonally, by submerged rhizomes, forming dense stands.
Fossil pollen and fruits from the Oligocene. Perianth of numerous bristles or scales. Inflorescence a double spadix with female flowers on the bottom and male flowers at the apex. Fruit an acene or follicle. Seed with endosperm present.