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.
               01 Genus †Annularia Sternb. (1821)
               02 Genus †Archaeocalamites Stur (1875)
               03 Genus †Asterophyllites Brongn. (1828), nom. cons.
               04 Genus †Astromyelon Will. (1883)
               05 Genus †Calamites Brongn. (1828), nom. cons.
               06 Genus †Calamocarpon Baxter (1963)
               07 Genus †Calamostachys Schimp. (1880)
               08 Genus †Cingularia C.E.Weiss (1870)
               09 Genus †Kallostachys Brush & Barghoorn (1955)
               10 Genus †Mazostachys Kosanke (1955)
               11 Genus †Paleostachya orth. inval. see Genus Palaeostachya C.E.Weiss (1876)