Phylum [Tracheophyta] Sinnott ex Caval.-Sm. (1998) - vascular plants
   Subphylum Polypodiophytina Reveal (1996) [monotypic]
     Class Polypodiopsida Cronquist, Takht. & Zimmerm. (1966) - ferns
       Subclass Polypodiidae Cronquist, Takht. & Zimmerm. (1966)
         Order Salviniales Link (1833) - water ferns
           16 Family Salviniaceae Martinov (1820) - floating ferns
           17 Family Marsileaceae Mirb. (1802) - clover ferns