[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Algae L. (1753) see [unranked] Algae
     Phylum Phaeophycota see Class Phaeophyceae Hansgirg (1886)
       Class Phaeophyceae Hansgirg (1886) - brown algae
         Order Chordariales
           Family Ralfsiaceae Farlow (1881)
             Genus Ralfsia Berk. (1843)
               1 Ralfsia bornetii Kuckuck (1894)
               2 Ralfsia disciformis P.L. Crouan & H.M. Crouan (1867)
               3 Ralfsia expansa (J.Agardh) J.Agardh (1848)
               4 Ralfsia fungiformis (Gunnerus) Setchell & N.L.Gardner (1924)
               5 Ralfsia lucida S. Lund (1967)
               6 Ralfsia ovata Rosenvinge (1893)
               7 Ralfsia pusilla (Strömfelt) Batters (1892)
               8 Ralfsia verrucosa (Aresch.) Aresch. (1845)