procaryotes
   Domain Bacteria Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum Proteobacteria Garrity and Holt 2001 nom. nud. see Phylum Proteobacteria Garrity et al. 2005 stat. inval.
       Class "Alphaproteobacteria" "Garrity and Holt 2001" nom. nud. see Class Alphaproteobacteria Garrity et al. 2006
         Order "Rhizobiales" "Garrity and Holt 2001" nom. nud. see Order Rhizobiales Kuykendall 2006
           01 Family Rhizobiaceae Conn 1938 (Approved Lists 1980)
           02 Family Bartonellaceae Gieszczykiewicz 1939 (Approved Lists 1980) [monotypic]
           03 Family Brucellaceae Breed et al. 1957 (Approved Lists 1980) see Family Bartonellaceae Gieszczykiewicz 1939 (Approved Lists 1980)
           04 Family "Phyllobacteriaceae" "Garrity and Holt 2001" nom. nud. see Family Phyllobacteriaceae Mergaert and Swings 2006
           05 Family "Methylocystaceae" "Garrity and Holt 2001" nom. nud. see Family Methylocystaceae Bowman 2006
           06 Family "Beijerinckiaceae" "Garrity and Holt 2001" nom. nud. see Family Beijerinckiaceae Garrity et al. 2006
           07 Family "Bradyrhizobiaceae" "Garrity and Holt 2001" nom. nud. see Family Bradyrhizobiaceae Garrity et al. 2006
           08 Family Hyphomicrobiaceae Babudieri 1950 (Approved Lists 1980)
           09 Family "Methylobacteriaceae" "Garrity and Holt 2001" nom. nud. see Family Methylobacteriaceae Garrity et al. 2006
           10 Family "Rhodobiaceae" "Garrity and Holt 2001" nom. nud. [monotypic] see Family Rhodobiaceae Garrity et al. 2006