[plants] Haeckel (1866) - plants
   vascular plants see Phylum Tracheophyta Sinnott ex Caval.-Sm. (1998)
     euphyllophytes see Clade Euphyllophyta Lecointre & Le Guyader 2006 [Cantino & Donoghue 2020]
       "Moniliformopses" Kenrick & P.R.Crane (1997), nom. inval. - ferns see Infraphylum Moniliformopses Kenrick & P.R.Crane (1997), nom. inval.
         Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883)
           Order †Calamitales Eichwald (1852) see Order Equisetales DC. ex Bercht. & J.Presl (1829)
             1 Family †Calamitaceae Unger (1840) see Family Calamostachyaceae S.V.Meyen (1978), nom. cons. prop.