Phylum: Charophyta   Family: Desmidiaceae

Xanthidium laeve (W. Schmidle) P.F.M. Coesel & K.J. Meesters 2023

The main feature of this taxon is the wide-open sinus and rounded basal angles. The spines are relatively short and stout.
Cell dimensions: L: 62-90 µm; B: 51-80 µm; Is: 17-23 µm; Sp: 13-22 µm; Overall LxB: 75-102 x 70-105 µm.
An infrequently recorded species, found in variously acidic waters such as loch-margins and moorland pools, also with Sphagnum.

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