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]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Alphaproteobacteria" Garrity et al., 2006 [monotypic]
                 Class Alphaproteobacteriaᵀ Garrity et al. 2006
                   Order Rhizobiales Kuykendall 2006
                     Family Xanthobacteraceae Lee et al. 2005
                       Genus Xanthobacterᵀ Wiegel et al. 1978 (Approved Lists 1980)
                         Xanthobacter viscosus Doronina and Trotsenko 2003