Unicellular, (non-N2 fixing)
Microcystis*, Gomphosphaeria

   
Filamentous, non-heterocystous (mostly non-N2 fixing)
Lyngbya*, Oscillatoria*

   
Filamentous, heterocystous (N2 fixing)
Anabaena*, Aphanizomenon*, Cylindrospermopsis*,
Nodularia*

* Contains toxic strains