Phylum: Charophyta Family: Desmidiaceae
Staurastrum controversum Brébisson
Not uncommon in acidic waters with vegetation such as loch-margins, peaty pools and ditches
References:
Ralfs, J. (1848) The British Desmidieae
West, W., West, G.S. & Carter, N. (1923) A Monograph of the British Desmidiaceae, Volume 5
Coesel, P.F.M. & Meesters, K.J. (2013) European Flora of the Desmid Genera Staurastrum and Staurodesmus