a class of unicellular and colonial blue-green algae. The cells are of various forms; usually the top and bottom portions are not differentiated. The cells in colonies are usually arranged randomly, although they are occasionally more or less regular and in some cases filamentous. In some Chroococcophyceae, cells and colonies form slimy layers that are attached fast to the substrate. They reproduce, as a rule, by simple cell division. Endospores, exospores and heterocysts are absent.
The Chroococcophyceae consist of three orders: Chroococcales, Entophysales, and Tubiella, including more than 35 genera. They are distributed in fresh water, as well as on land substrates and in soil. Some Chroococcophyceae are important in the formation of medicinally useful mud.