Phylum Cyanobacteria (ex Stanier 1974) Cavalier-Smith 2002 stat. inval. - cyanobacteria see Phylum Cyanobacteriota Oren et al. 2022
   Subgroup Chroococcacean
     1 Genus Synechococcus C. Nägeli (1849) see Genus Synechococcus Nägeli 1849
     2 Genus Synechocystis C. Sauvageau (1893) see Genus Synechocystis Sauvageau 1893
     3 Genus Chamaesiphon A.Braun (1864) see Genus Chamaesiphon Braun 1864
     4 Genus Gloeobacter Rippka, Waterbury & Cohen-Baz. (1974), nom. inval. see Genus Gloeobacter Rippka, Waterbury & Cohen-Baz. (2013)
     5 Genus Gloeothece C. Nägeli (1849), nom. cons. see Genus Gloeothece Nägeli 1849 nom. cons.
     6 Genus Microcystis Lemmerm. (1907), nom. cons. see Genus Microcystis Kützing ex Lemmermann 1907 nom. cons.
     7 Genus Aphanothece C. Nägeli (1849), nom. cons. see Genus Aphanothece Nägeli 1849 nom. cons.