Phylum: Charophyta   Family: Desmidiaceae

Actinotaenium diplosporum (P.M. Lundell) E. Teiling 1954

Cells cylindric with slightly diverging lateral sides and broadly rounded apex. Sinus shallow but obvious in most cells. Chloroplast asteroid with one pyrenoid.
Single cell dimension: L: 55.6 µm; B: 22.1 µm; L/B: 2.52.
A rare acidophile of moorland pools and bogs, including with Sphagnum.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition). Desmids of the Lowlands.
Van Westen, M.C. (2024).Sieralgen in Drenthe.