Phylum: Charophyta   Family: Desmidiaceae

Staurodesmus dejectus  (J. Ralfs) E. Teiling 1967

Predominantly a triradiate species with fairly short spines pointing obliquely upwards. The isthmus can be slightly extended.
Cell dimensions: L: 22-30 µm; B: 21-33 µm; Is: 6-7.7 µm; Sp: 3-8 µm; Overall LxB: 28-35 x 25-35.
Zygospore: minus projections: 26-28 µm; overall: 42-44 µm.
Common in environments that have varying amounts of acidity. Found in the plankton of lochs and moorland bogs and pools.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013). European Flora of the Desmid Genera Staurastrum and Staurodesmus.
Van Westen, M.C. (2024). Sieralgen in Drenthe.