Spirodela Schleid.

1 species native Aust.; Qld, NSW, Vic., WA, NT

Spirodela polyrhiza (L.) Schleid.

Small, floating, aquatic herbs frequently forming a green carpet on the surface of still waters. Cladodes elliptic to obovate. Roots 5–18 per cladode. Inflorescence minute, in a pocket on the margin of the cladode, with 1 female flower and 2 males enclosed in a sheath. Widespread in still water, ditches, ponds and creeks