Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Pteridobiotina Britton & A. Br. (1896)
     Superdivision Cycadophytanae Doweld (2001) see Superphylum Cycadophytanae Doweld (2001)
       Division Gnetophyta Bessey (1907) [monotypic]
         Class Gnetopsida Eichler ex Kirpot. (1884)
           Order Welwitschiales Skottsb. ex Reveal (1993) [monotypic]
             Family Welwitschiaceae Caruel (1879), nom. cons.
               Genus †Welwitschiophyllum Dilcher, Bernardes-de-Oliveira, D.Pons & T.A.Lott (2005)