Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883)
   gymnosperms see Class Spermatopsida
     Subclass Gnetidae Pax (1894) see Class Gnetopsida Eichler ex Kirpot. (1884)
       1 Order Welwitschiales Skottsb. ex Reveal (1993)
       2 Order Gnetales Mart. (1835)
       3 Order Ephedrales Dumort. (1829)