Phylum [Tracheophyta] Sinnott ex Caval.-Sm. (1998) - vascular plants
   Subphylum Polypodiophytina Reveal (1996) [monotypic]
     Class Polypodiopsida Cronquist, Takht. & Zimmerm. (1966) - ferns
       1 Subclass Equisetidae Warm. (1883) [monotypic]
       2 Subclass Ophioglossidae Klinge (1882)
       3 Subclass Marattiidae Klinge (1882) [monotypic]
       4 Subclass Polypodiidae Cronquist, Takht. & Zimmerm. (1966)