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)
           Order Equisetales DC. ex Bercht. & J.Presl (1829)
             Family †Calamostachyaceae S.V.Meyen (1978), nom. cons. prop.
               Genus †Paleostachya orth. inval. see Genus Palaeostachya C.E.Weiss (1876)