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 Beggiatoales Buchanan 1957 nom. inval. see Order Beggiatoales Buchanan 1957 (Approved Lists 1980)
         Family Achromatiaceae Massart 1901 nom. inval. see Family Achromatiaceae Massart 1901 (Approved Lists 1980)
           Genus Achromatium Schewiakoff 1893 nom. inval. see Genus Achromatium Schewiakoff 1893 (Approved Lists 1980)