[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)
             1 Genus Hapalospongidion Saunders (1899)
             2 Genus Lithoderma J.E. Areschoug (1875)
             3 Genus Porterinema Waern (1952)
             4 Genus Pseudolithoderma Svedelius, in Engl. & Prantl (1911)
             5 Genus Ralfsia Berk. (1843)
             6 Genus Stragularia Stroemfelt (1886)