See text Coelastrum is a genus of green algae in the Scenedesmaceae family.

It is a common component of the phytoplankton in freshwater habitats such as ponds, lakes, waterfalls, and temporary pools of water,[1] particularly eutrophic ones.

[6] However, a great deal of morphological variability exists, which complicates species delimitation and therefore identification.

[7] Coelastrum was once classified as a member of its own family, the Coelastraceae, which has always considered to be similar to the Scenedesmaceae.

[7] Species of Coelastrum have been tested for uses in biotechnology, such as lipid or astaxanthin production and wastewater treatment.