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 "Gammaproteobacteria" Garrity et al., 2005 [monotypic]
                 Class Gammaproteobacteriaᵀ Garrity et al. 2005
                   Order Lysobacterales Christensen and Cook 1978 (Approved Lists 1980)
                     Family Lysobacteraceaeᵀ Christensen and Cook 1978 (Approved Lists 1980)
                       Genus Xylella Wells et al. 1987 [monotypic]
                         Xylella fastidiosaᵀ Wells et al. 1987
                           1 Xylella fastidiosa subsp. fastidiosaᵀ (Wells et al. 1987) Schaad et al. 2009
                           2 Xylella fastidiosa subsp. multiplex Schaad et al. 2009