Phylum: Charophyta   Family: Desmidiaceae

Cosmarium quinarium P. Lundell 1871

A striking species with large round granules around the periphery and a little less organised in the centre of the semicell.
Cell dimensions: L: 39-44 µm; B: 34-38 µm; Is: 11-13 µm; Th: 23-25 µm; L/B: 1.13-1.17.
A widespread species but never common. Found in mainly mesotrophic moorland pools and shallow lochans.

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