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.
Single cell dimensions: L: 26.7 µm; B: 20.6 µm; Is: 12.1 µm; Th: 14.2; L/B: 1.30.
The only find to date has come from 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.