Phylum: Charophyta Family: Desmidiaceae
Staurodesmus dejectus var. brevispinus (Nygaard) Coesel
A recently described variety which 'Differs from the nominate in having semicells with concave to straight apex and relatively long spines' - Coesel & Meesters (2007)
References:
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands