Phylum: Charophyta   Family: Desmidiaceae

Staurodesmus pterosporus (P. Lundell) Bourrelly 1966

An acidophile of little known distribution. Very similar to Staurodesmus controversus var. crassus but with more pronounced mammillate apical angles and longer spines. Current finds have been in moorland pools and bogs.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013) European Flora of the Desmid Genera Staurastrum and Staurodesmus.
West, W., West, G.S. & Carter, N. (1923) A Monograph of the British Desmidiaceae, Volume 5.