plantenrijk Haeckel (1866) - plants
   [Division] Protophyta Sachs 1874 - primitive plants
     Class Schizomycetes Nägeli 1857 (Approved Lists 1980) - bacteria and related forms
       Order Eubacteriales Buchanan 1917 (Approved Lists 1980) see Order Clostridiales Prévot 1953 (Approved Lists 1980)
         Family Enterobacteriaceae Rahn 1937 (Approved Lists 1980)
           Genus Proteus Hauser 1885 (Approved Lists 1980)