Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Pteridobiotina Britton & A. Br. (1896)
     Superdivision Pteridophytanae Doweld (2001) [monotypic] see Superphylum Pteridophytanae Doweld (2001)
       Division Monilophyta Cantino & Donoghue
         Class Polypodiopsida Cronquist, Takht. & Zimmerm. (1966) - ferns
           Order Salviniales Link (1833) - water ferns
             Family Salviniaceae Martinov (1820) - floating ferns
               1 Genus Azolla Lam. (1783)
               2 Genus Salvinia Séguier (1754)