Phylum: Charophyta   Family: Desmidiaceae

Cosmarium obliquum C.F.O. Nordstedt 1873

A strange desmid that is quite amorphous and lacks symmetry in apical view. It also occurs in a triradiate form, but this doesn’t have any taxonomic value. In consequence dimensions cover a broad spectrum of sizes.
Cell dimensions: L: 18.8-32 µm; B: 14.5-22.7 µm; Is: 11.1-20.4; Th: c.11 µm; L/B: 1.16-1.45.
An acidophile of moorland bogs and loch-margins, often with Sphagnum, also from moss on dripping rocks. Infrequently recorded.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.
West, W. & West, G.S. (1908). A Monograph of the British Desmidiaceae, Volume 3.