Phylum [Tracheophyta] Sinnott ex Caval.-Sm. (1998) - vascular plants
   Subphylum Polypodiophytina Reveal (1996) [monotypic]
     Class Polypodiopsida Cronquist, Takht. & Zimmerm. (1966) - ferns
       Subclass Ophioglossidae Klinge (1882)
         Order Psilotales Prantl (1884) [monotypic]
           Family Psilotaceae J.W.Griff. & Henfr. (1855) - whisk ferns
             1 Genus Psilotum Sw. (1801)
             2 Genus Tmesipteris Bernh. (1801)