plants Haeckel (1866) - plants
   Division Charophyta Migula (1889) - charophyte algae and embryophytes see charophytes
     Subdivision [Streptophytina] see [unranked] Streptophytina Lewis & McCourt (2004)
       Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883)
         Vascular Plants see Phylum Tracheophyta Sinnott ex Caval.-Sm. (1998)
           [Ferns]
             Subclass Ophioglossidae Klinge (1882)
               Order Ophioglossales Link (1833) [monotypic]
                 Family Ophioglossaceae Martinov (1820) - ophioglossoids
                   1 Genus Botrychium Sw. (1801) - grapeferns
                   2 Genus Helminthostachys Kaulf. (1824)
                   3 Genus Mankyua B.Y.Sun, M.H.Kim & C.H.Kim (2002)
                   4 Genus Ophioglossum L. (1753) - adder tongues