plantenrijk Haeckel (1866) - plants
   [Division] Protophyta Sachs (1874) - primitive plants
     Class Schizomycetes Nägeli 1857 nom. inval. - bacteria and related forms see Class Schizomycetes Nägeli 1857 (Approved Lists 1980) nom. illeg., nom. rej.
       Order Pseudomonadales Orla-Jensen 1921 nom. inval. see Order Pseudomonadales Orla-Jensen 1921 (Approved Lists 1980)
         Family Nitrobacteriaceae (sic) Buchanan 1917 nom. inval. see Family Nitrobacteraceae corrig. Buchanan 1917 (Approved Lists 1980)
           1 Genus Nitrobacter Winogradsky 1892 nom. inval., nom. cons. see Genus Nitrobacter Winogradsky 1892 (Approved Lists 1980) nom. cons.
           2 Genus Nitrosococcus Winogradsky 1892 nom. cons., nom. inval. see Genus Nitrosococcus Winogradsky 1892 nom. cons. (Approved Lists 1980)
           3 Genus Nitrosomonas Winogradsky 1892 nom. inval., nom. cons. see Genus Nitrosomonas Winogradsky 1892 (Approved Lists 1980) nom. cons.