Phylum: Charophyta   Family: Desmidiaceae

Cosmarium fictophaseolus F.A.C. Kouwets 2025

Recently renamed after the poorly described Cosmarium phaseolus. One of several small, smooth-walled taxa that are not always easy to evaluate.
Cell dimensions: L: 19.9-23.2 µm, B: 18-21.8 µm, Is. 6.4-7.8 µm; Th. 12-14 µm L/B: 1.04-1.11.
Found in acidic waters such as lochs, moorland pools and abandoned peat-cuttings. Because of the original confusion, the status in the Outer Hebrides is uncertain but thought to be scarce.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium.