Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [organisms] 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 Protoctista Hogg, 1860]
               [Phylum Xanthophyta Allorge, in Fritsch (1935)] see Class Xanthophyceae P. Allorge ex Fritsch (1935)
                 [Class Heterosiphonales] see Order Vaucheriales Bohlin (1901)