Kingdom Protoctista Hogg, 1860
   Phylum Chlorophyta Pascher (1914) - green algae
     1 ?Class Prasinophyceae T. Christensen, 1962 ex Ø. Moestrup & J. Throndsen (1988) - prasinophytes see [unranked] prasinophytes
     1.0 Class Micromonadophyceae Mattox & Stewart (1984) see Class Prasinophyceae T. Christensen, 1962 ex Ø. Moestrup & J. Throndsen (1988)
     2 Class Chlorophyceae Wille (1884) - chlorophytes
     2.0.1 Class Oedogoniophyceae H. Ettl (1981) see Class Chlorophyceae Wille (1884)
     2.0.2 Class Chlamydophyceae H. Ettl (1981) see Class Chlorophyceae Wille (1884)
     3 Class Ulvophyceae K.R. Mattox & K.D. Stewart (1984) - ulvophytes
     3.0.1 Class Bryopsidophyceae Bessey (1907) see Class Ulvophyceae K.R. Mattox & K.D. Stewart (1984)
     3.0.2 Class Codiolophyceae P. Kornmann (1973) see Class Ulvophyceae K.R. Mattox & K.D. Stewart (1984)
     4 Class Charophyceae Rabenh. (1863) - stoneworts
     5 ?Order Pedinomonadales Moestrup (1991)
     6 ?Order Microthamniales M. Melkonian, in L. Margulis et al., eds. (1990)
     6.0 Class Pleurastrophyceae K.R. Mattox & K.D. Stewart (1984) see Class Trebouxiophyceae T. Friedl (1995)
     7 ?Order Prasiolales Fritsch
     8 ?Order Trentepohliales Chadef. ex R.H. Thompson & D.E. Wujek (1997)