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 Rhodospirillales Pfennig and Trüper 1971 (Approved Lists 1980)
                     Family Rhodospirillaceae Pfennig and Trüper 1971 (Approved Lists 1980)
                       Genus Limibacillus Kim et al. 2015
                       Genus Nitrospirillum Lin et al. 2015
                       Genus Taonella Xi et al. 2013
                       Genus Tistlia Díaz-Cárdenas et al. 2010
                       01.1 Genus Insolitispirillum Yoon et al. 2007
                       01.2 Genus Novispirillum Yoon et al. 2007
                       02.1 Genus Rhodospirillumᵀ Molisch 1907 (Approved Lists 1980) [monotypic]
                       02.2 Genus Pararhodospirillum Lakshmi et al. 2014
                       03 Genus Aestuariispira Park et al. 2014 [monotypic]
                       04.1 Genus Azospirillum Tarrand et al. 1979 (Approved Lists 1980)
                       04.2 Genus Niveispirillum Lin et al. 2014
                       05 Genus Caenispirillum Yoon et al. 2007
                       06 Genus Constrictibacter Yamada et al. 2011 [monotypic]
                       07 Genus Defluviicoccus corrig. Maszenan et al. 2005 [monotypic]
                       08 Genus Desertibacter Liu et al. 2011 [monotypic]
                       09 Genus Dongia Liu et al. 2010
                       10 Genus Elstera Rahalkar et al. 2012 [monotypic]
                       11 Genus Ferrovibrio Sorokina et al. 2013 [monotypic]
                       12 Genus Fodinicurvata Wang et al. 2009
                       13 Genus Inquilinus Coenye et al. 2002
                       14 Genus Lacibacterium Sheu et al. 2013 [monotypic]
                       15 Genus Limimonas Amoozegar et al. 2013 [monotypic]
                       16 Genus Magnetospira Williams et al. 2012 [monotypic]
                       17 Genus Magnetospirillum Schleifer et al. 1992
                       18 Genus Magnetovibrio Bazylinski et al. 2013 [monotypic]
                       19 Genus Marispirillum Lai et al. 2009 [monotypic]
                       20 Genus Nisaea Urios et al. 2008
                       21 Genus Oceanibaculum Lai et al. 2009
                       22 Genus Pelagibius Choi et al. 2009 [monotypic]
                       23 Genus Phaeospirillum Imhoff et al. 1998
                       24 Genus Phaeovibrio Lakshmi et al. 2011 [monotypic]
                       25 Genus Rhodocista Kawasaki et al. 1994
                       26 Genus Rhodospira Pfennig et al. 1998 [monotypic]
                       27 Genus Rhodovibrio Imhoff et al. 1998
                       28 Genus Roseospira Imhoff et al. 1998
                       29 Genus Skermanella Sly and Stackebrandt 1999
                       30 Genus Telmatospirillum Sizova et al. 2007 [monotypic]
                       31 Genus Thalassobaculum Zhang et al. 2008 [monotypic]
                       32 Genus Thalassospira López-López et al. 2002
                       33 Genus Tistrella Shi et al. 2003 [monotypic]