Botryococcus is a genus of green algae. It is a microscopic or semi-microscopic alga that is found in freshwater habitats worldwide. It consists of colonies of cells in an irregular, gelatinous matrix.
Botryococcus produces high amounts of oil, which often make the colonies colored yellowish to reddish. When seen with a microscope, colonies release oil under the pressure of a cover slip. Because of its high amounts of oil, Botryococcus is of interest to the field of biotechnology, as it is a promising source of biofuel.
In addition to its current biosynthetic capabilities, fossils of the genus are known since Precambrian times, and form the single largest biological contributor to crude oil, and are a major component of oil shales.