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 Family Marsileaceae Mirb. (1802) - clover ferns 1 Genus Marsilea L. (1753) 2 Genus Pilularia L. (1753) 3 Genus Regnellidium Lindm. (1904)