Procaryotic Genera
   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
           Family "Methylocystaceae" "Garrity and Holt 2001" nom. nud. see Family Methylocystaceae Bowman 2006
             Genus Methylocystis (ex Whittenbury et al. 1970) Bowman et al. 1993