Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883)
   gymnosperms see Class Spermatopsida
     Subclass Cycadidae Pax (1894) - cycads
       1 Order Cycadales Pers. ex Bercht. & J.Presl (1820) - cycads