life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukarya Chatton, 1925 see Domain Eukaryota Chatton, 1925
     Kingdom Plantae Haeckel (1866) - plants
       Tracheata see Phylum Tracheophyta Sinnott ex Caval.-Sm. (1998)
         Phylum Psilophyta see Infraphylum Psilophytae T. Cavalier-Sm. (1998)
           Genus Psilotum Sw. (1801)
             1 Psilotum nudum (L.) P.Beauv. (1805) - whisk fern
             2 Psilotum complanatum Sw. (1801) - flatfork fern