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 Cycadophytanae Doweld (2001)
           Phylum †Peltaspermophyta Doweld (2001) see Division Pteridospermatophyta Meyen
             Class †Pentoxylopsida D.D.Pant ex Doweld (2001), nom. inval. [monotypic] see Class Pentoxylopsida D.D.Pant (1959)
               Order †Pentoxylales Pilg. & Melchior (1954) [monotypic]
                 Family †Pentoxylaceae Pilg. & Melchior (1954)
                   1 Genus †Pentoxylon B.P.Srivast. (1944)