Phylum: Charophyta   Family: Desmidiaceae

Cosmarium submeneghinii  F.A.C. Kouwets 2025

This recently described species is borne out of the chaotic state of Cosmarium meneghinii Ralfs 1848, with its innumerable varieties. It’s morphologically variable and can occasionally support a slight tumour when viewed apically.
Cell dimensions: L: 17.2-18.9 µm; B: 13.7-15.2 µm; Is: 3.5-4.5 µm; Th: 8.9-10 µm; L/B: 1.19-1.32.
Found in the plankton of moorland pools and lochs, also in ephemeral winter floods. A widespread species but not as common as it was once reported, especially for Scotland generally.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.