Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Lycopodiobiotina Doweld (2001)
     Division Lycopodiophyta D.H.Scott (1900) see Phylum Lycopodiophyta D.H.Scott (1900)
       Class Isoëtopsida Rolle (1884)
         Order Isoëtales Prantl (1874)
           Family Isoëtaceae Rchb. (1828) [monotypic]
             Genus Isoëtes L. (1753)