Viridiplantae Cavalier-Smith, 1981 - green plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Chlorophyta Pascher (1914) - green algae
     core chlorophytes
       Class Trebouxiophyceae T. Friedl (1995) - trebouxiophytes
         Chlorellales
           .1 Genus Helicosporidium Keilin (1921)
           1 Genus Chlorella M. Beijerinck (1890)
           2 Genus Nanochloris
           3 Genus Prototheca W. Krüger (1894), nom. dub.