Phylum: Chlorophyta   Family: Botryococcaceae

Botryococcus braunii  Kützing 1849

Widespread in ponds, lochs, ditches, bogs, etc. Usually in waters which are slightly acidic. There is variation in the colour of the colonies from green to orange. The cells are also quite variable, both in shape and size.

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition) The Freshwater Algal Flora of the British Isles.