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)
       Order Welwitschiales Skottsb. ex Reveal (1993)
         1 Family Welwitschiaceae Caruel (1879), nom. cons.