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 Polypodiales Link (1833) - cathetogyrates Suborder Pteridineae [monotypic] Family Pteridaceae E.D.M.Kirchn. (1831) - pteroids Subfamily Pteridoideae Link (1841) Genus Tryonia