Taxonomic status:Accepted
Occurrence status:Present
Establishment means:Introduced
Leaves opposite, submerged leaves sessile or shortly petiolate, finely dissected; floating leaves few or absent early, lamina rhombic to elliptic, entire, peltate. Flowers with 3–6 stamens; carpels no more than 4.
About 7 species, all native to North or South America; 1 species naturalised in Australia.