Division Cyanophyta (which is in Kingdom Monera) contains the cyanobacteria, which are also known as blue-green algae and cyanophytes. These organisms are one-celled or colonial prokaryotes that contain chlorophyll (but not chloroplasts, which contain the chlorophyll in true plants).

Cyanobacteria are autotrophs (they create their own energy via photosynthesis) and reproduce through fission (splitting in two). There are over 7,500 species of cyanobacteria and they are found in many environments: damp soil and rocks, fresh water, and salt water.