Phylum: Charophyta Family: Desmidiaceae
Cosmarium sphagnicola var. armatum Willi Krieger & Gerloff 1965
There are a number of similar small cells that display four granules in an asymmetric configuration. Kouwets (in manuscript) is making great strides in sorting them out. See his proposed new name and detailed text for the desmid listed here (l.c., Cosmarium pseudosphagnicola F.A.C. Kouwets 20XX spec. nov., p. 519). A lot more research is needed to get a better understanding of distribution.
Krieger, W. & Gerloff, J. (1962-9) Die Gattung Cosmarium.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.