Domain Eucaryota
   Subdomain Chlorota Doweld (2001)
     Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
       Subkingdom Pteridobiotina Britton & A. Br. (1896)
         Superphylum Pteridophytanae Doweld (2001)
           Phylum †Cladoxylophyta Doweld (2001) [monotypic] see Division Monilophyta Cantino & Donoghue
             Class †Cladoxylopsida Novák (1930) - cladoxylopsids see Class Equisetopsida C.Agardh (1825)
               Order †Steloxylales Doweld (2001) [monotypic] see Order Cladoxylales W.Zimm. (1930)
                 Family †Steloxylaceae C.A.Arnold ex Doweld (2001) [monotypic] see Family Cladoxylaceae Unger (1856)
                   1 Genus †Steloxylon Solms (1897)