Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Biota
           Domain Bacteria Woese et al. 1990
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Alphaproteobacteria" [monotypic]
                 Class Alphaproteobacteriaᵀ Garrity et al. 2006
                   Order Rhizobiales Kuykendall 2006
                     Genus Methyloceanibacter Takeuchi et al. 2014, incertae sedis [monotypic]
                     Family Roseiarcaceae Kulichevskaya et al. 2014 [monotypic]
                     01 Genus Amorphus Zeevi Ben Yosef et al. 2008, incertae sedis
                     02 Genus Vasilyevaea Yee et al. 2010, incertae sedis
                     03 Family Rhizobiaceaeᵀ Conn 1938 (Approved Lists 1980)
                     04 Family "Aurantimonadaceae"
                     05 Family Bartonellaceae Gieszczykiewicz 1939 (Approved Lists 1980) [monotypic]
                     06 Family Brucellaceae Breed et al. 1957 (Approved Lists 1980)
                     07 Family Phyllobacteriaceae Mergaert and Swings 2006
                     08.1 Genus Alsobacter Bao et al. 2014, incertae sedis [monotypic]
                     08.2 Family Methylocystaceae Bowman 2006
                     08.3 Family Beijerinckiaceae Garrity et al. 2006
                     09 Family Bradyrhizobiaceae Garrity et al. 2006
                     10.1 Genus Bauldia Yee et al. 2010, incertae sedis
                     10.2 Family Hyphomicrobiaceae Babudieri 1950 (Approved Lists 1980)
                     10.3 Family Xanthobacteraceae Lee et al. 2005
                     11 Family Methylobacteriaceae Garrity et al. 2006
                     12 Family Rhodobiaceae Garrity et al. 2006
                     13 Family Cohaesibacteraceae Hwang and Cho 2008 [monotypic]