Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Pteridobiotina Britton & A. Br. (1896)
     Superdivision Pteridophytanae Doweld (2001) [monotypic] see Superphylum Pteridophytanae Doweld (2001)
       Division Monilophyta Cantino & Donoghue
         Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883)
           a Order Equisetales DC. ex Bercht. & J.Presl (1829)
           b Order †Pseudoborniales E.W.Berry (1920) [monotypic]
           c Order †Sphenophyllales Wettst. (1903) [monotypic]
           d Order †Cladoxylales W.Zimm. (1930)