prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   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
         01 Order "Parvularculales" [monotypic]
         02 Order Caulobacterales Henrici and Johnson 1935 (Approved Lists 1980)
         03 Order Kiloniellales Wiese et al. 2009 [monotypic]
         04 Order Kordiimonadales Kwon et al. 2005
         05 Order Magnetococcales Bazylinski et al. 2013 [monotypic]
         06 Order Rhizobiales Kuykendall 2006
         07 Order Rhodobacterales Garrity et al. 2006 [monotypic]
         08 Order Rhodospirillales Pfennig and Trüper 1971 (Approved Lists 1980)
         09 Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980)
         10 Order Sneathiellales Kurahashi et al. 2008 [monotypic]
         11 Order Sphingomonadales Yabuuchi and Kosako 2006
         12 Genus Breoghania Gallego et al. 2011, incertae sedis
         13 Genus Eilatimonas Paramasivam et al. 2013, incertae sedis
         14 Genus Geminicoccus Foesel et al. 2008, incertae sedis
         15 Genus Hartmannibacter Suarez et al. 2014, incertae sedis
         16 Genus Phreatobacter Tóth et al. 2014, incertae sedis
         17 Genus Rhizomicrobium Ueki et al. 2010, incertae sedis