living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Plantae Haeckel (1866) - plants
       Subkingdom Embryobionta Cronquist, Takht. & W.Zimm.
         Division Psilotophyta Heintze (1927) see Phylum Psilophyta
           Subdivision Psilotopsida Scott (1909) see Class Psilotopsida D.H.Scott (1909)
             Order Psilotales Prantl (1884)
               1 Family Psilotaceae J.W.Griff. & Henfr. (1855) - whisk ferns