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 Cyatheales A.B.Frank (1877) - tree ferns Family Cyatheaceae Kaulf. (1827) - scaly tree ferns Genus Sphaeropteris Bernh.