Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Clade neomura Cavalier-Smith, 1987
             Domain Eukaryota Chatton, 1925 - eukaryotes
               Clade discaria Cavalier-Smith, 2021
                 Clade natates Cavalier-Smith, 2021
                   Clade photaria Cavalier-Smith, 2021
                     Clade eucorta Cavalier-Smith, 2021
                       Superkingdom Corticata Lankester, 1878 - corticates
                         Kingdom Chromista Caval.-Sm. (1981) - chromists
                           Subkingdom Harosa Cavalier-Smith, 2010
                             [crown] Clade Sar Adl et al. 2012 [Simpson & Dunthorn 2020]
                               Infrakingdom Halvaria Cavalier-Smith, 2010
                                 Superphylum Heterokonta Caval.-Sm. (1986)
                                   Phylum Ochrophyta Caval.-Sm. (1995)
                                     Subphylum Phaeista Caval.-Sm. (1995)
                                       Infraphylum Marista Caval.-Sm. (2006)
                                         Superclass Fucistia Caval.-Sm. (1995)
                                           Class Phaeophyceae Hansgirg (1886) - brown algae
                                             Order Chordariales
                                               Family Ralfsiaceae Farlow (1881)
                                                 Genus Ralfsiaᵀ Berk. (1843)
                                                   Ralfsia bornetii Kuckuck (1894)
                                                   Ralfsia disciformis P.L. Crouan & H.M. Crouan (1867)
                                                   Ralfsia expansa (J.Agardh) J.Agardh (1848)
                                                   Ralfsia fungiformis (Gunnerus) Setchell & N.L.Gardner (1924)
                                                   Ralfsia lucida S. Lund (1967)
                                                   Ralfsia occidentalis Hollenberg
                                                   Ralfsia ovata Rosenvinge (1893)
                                                   Ralfsia pusilla (Strömfelt) Batters (1892)
                                                   Ralfsia verrucosa (Aresch.) Aresch. (1845)