Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981) Subkingdom Pteridobiotina Britton & A. Br. (1896) Superdivision Pteridophytanae Doweld (2001) [monotypic] see Superphylum Pteridophytanae Doweld (2001) Division Monilophyta Cantino & Donoghue Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883) Order †Cladoxylales W.Zimm. (1930) Family †Cladoxylaceae Unger (1856) 1 Genus †Cladoxylon Unger (1856) 2 Genus †Pseudosporochnus Potonié ex Zeiller (1908) 3 Genus †Schizoxylon Unger (1856), nom. illeg. 4 Genus †Steloxylon Solms (1897) 5 Genus †Xenocladia C.A.Arnold (1940)