plantenrijk Haeckel (1866) - plants
   [Division] Protophyta Sachs 1874 - primitive plants
     Class Schizomycetes Nägeli 1857 (Approved Lists 1980) - bacteria and related forms
       Order Beggiatoales Buchanan 1957 (Approved Lists 1980) see Order Thiotrichales Garrity et al. 2005
         Family Achromatiaceae Massart 1901 (Approved Lists 1980) see Family Thiotrichaceae
           Genus Achromatium Schewiakoff 1893 (Approved Lists 1980)