Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 2024
             Kingdom Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Pseudomonadotaᵀ Garrity et al. 2021
                 Class Betaproteobacteria Garrity et al. 2006
                   Order Rhodocyclales Garrity et al. 2006
                     Family Rhodocyclaceaeᵀ Garrity et al. 2006
                       Genus Rhodocyclusᵀ Pfennig 1978 (Approved Lists 1980)
                         1 Rhodocyclus purpureusᵀ Pfennig 1978 (Approved Lists 1980)
                         2 Rhodocyclus tenuis (Pfennig 1969) Imhoff et al. 1984