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 Ephedrales Dumort. (1829)
         Family Ephedraceae Dumort. (1829), nom. cons. - Mormon-tea family
           1 Genus Ephedra L. (1753) - sea grape