Botryococcus
Botryococcus is a genus of green algae. The cells form an irregularly shaped aggregate. Thin filaments connect the cells. The cell body is ovoid, 6 to 10 μm long, and 3 to 6 μm wide. 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. Taxonomy
The genus and its holotype were described in 1849 by Friedrich Traugott Kützing. Description
Appears as colonies of cells irregularly arranges cells in a folded mucilage. Cells spherical or oval, chloroplast net-like with a single pyrenoid. Ecology
The algae is frequently found in plankton in waters with differing characteristics and a wide geographic distribution. It is an important component of algal blooms and the discoloration of water. It is known to reproduce asexually but zoospores and sexual reproduction are unknown. Species
There are 13 accepted species in the genus. Botryococcus australis 
Botryococcus balkachicus 
Botryococcus braunii 
Botryococcus calcareus 
Botryococcus canadensis 
Botryococcus comperei 
Botryococcus fernandoi 
Botryococcus neglectus 
Botryococcus pila 
Botryococcus protuberans 
Botryococcus pusillus 
Botryococcus terribilis 
Botryococcus terricola

References

Trebouxiophyceae genera
Trebouxiophyceae
Trebouxiales
Taxa named by Friedrich Traugott Kützing