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 Caulobacterales Henrici and Johnson 1935 (Approved Lists 1980)
                     Family Hyphomonadaceae Lee et al. 2005
                       Genus Hirschia Schlesner et al. 1990
                         1 Hirschia balticaᵀ Schlesner et al. 1990
                         2 Hirschia litorea Park and Yoon 2013
                         3 Hirschia maritima Kang and Lee 2009