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 Methanomonadeceae (sic) "Breed et al. 1957" nom. inval. see Family Methanomonadaceae Breed et al. 1957 nom. inval.
           Genus Hydrogenomonas Orla-Jensen 1909 nom. nud.