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 Magnoliophyta Cronquist, Takht. & Zimmerm. ex Reveal (1996) see Infraphylum Angiospermae auct.
             Subphylum †Caytoniophytina Doweld (2001) [monotypic]
               Class †Caytoniopsida H.H.Thomas ex Frenguelli (1946) [monotypic]
                 Order †Caytoniales E.Wulff (1926) [monotypic]
                   Family †Caytoniaceae Kräusel (1926)
                     Genus †Caytonia H.H.Thomas (1925), incertae sedis