Ceratophyllaceae is a cosmopolitan family of flowering plants including one living genus[3] commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions.

Living Ceratophyllum grows completely submerged, usually, though not always, floating on the surface, and does not tolerate drought.

Ceratophyllaceae was considered a relative of Nymphaeaceae and included in Nymphaeales in the Cronquist system, but research has shown that it is not closely related to Nymphaeaceae or any other extant plant family.

[1][2][5] The APG IV system accepts the phylogeny shown below:[4] Amborellales Nymphaeales Austrobaileyales magnoliids Chloranthales monocots Ceratophyllales eudicots The extinct family Montsechiaceae containing the genus Montsechia has also been placed in the order Ceratophyllales.

[6] The family contains one living genus, and several extinct genera described from the fossil record, including one of the earliest fruit bearing (in the form of an achene) plants, the Dakota formation freshwater genus Donlesia from Early Cretaceous.