Phylum: Charophyta   Family: Desmidiaceae

Cosmarium pseudosaxicola F.A.C. Kouwets 2025

This recently described species needs to be carefully compared with C. cedercreutzii Grönblad 1921. That species is slightly larger with a higher L/B ratio, it also has a smooth central cell-wall unlike the present species that supports some flattened warts, but these can be difficult to see and can be reduced.
Cell dimensions: L: 26.7-28.2 µm; B: 19.7-20.9 µm; Is: 11.2-12.3 µm; Th: 14.2-15.5; L/B: 1.30-1.37.
Found with moss on wet rocks. Distribution is unknown due to earlier taxonomic confusion.

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