Salviniaceae (or formerly Salviniaceæ) is a family of heterosporous ferns in the order Salviniales. The Salviniaceae contain the two genera Azolla and Salvinia, with a total of ca 20 known species. Azolla was previously placed in its own family, Azollaceae, but recent research has shown Azolla and Salvinia to be sister genera with the likely phylogenic relationship shown in the following diagram.