Phylum: Charophyta   Family: Desmidiaceae

Cosmarium variolatum P. Lundell 1871

A widespread and common species in the arctic-alpine regions of Europe. Found on the acidic side of neutral in oligo-mesotrophic habitats. In the Outer Hebrides it is proving to be quite scarce. More sampling is required as we have the right habitat.

References: 
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.
West, W. & West, G.S. (1905) A Monograph of the British Desmidiaceae, Volume 2.