[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Alphaproteobacteria Garrity et al. 2006
         Order Rhodospirillales Pfennig and Trüper 1971 (Approved Lists 1980)
           Family Rhodospirillaceae Pfennig and Trüper 1971 (Approved Lists 1980)
             Genus Rhodospirillum Molisch 1907 (Approved Lists 1980)
               Rhodospirillum rubrum (Esmarch 1887) Molisch 1907 (Approved Lists 1980)