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 Cycadophyta Bessey (1907) see Subclass Cycadidae Pax (1894)
             Class Cycadopsida Brongn. (1843)
               Subclass Zamiidae Doweld (2001)
                 2 Order †Nilsoniales (1935), orth. inval. [monotypic] see Order Nilssoniales W.Zimm. (1930)
                 3 Order Dioales Doweld (2001) [monotypic] see Order Zamiales Burnett (1835)
                 4 Order Stangeriales Doweld (2001) [monotypic] see Order Zamiales Burnett (1835)
                 5 Order Zamiales Burnett (1835)