Phylum: Charophyta Family: Desmidiaceae
Cosmarium isthmochondrum Nordstedt 1873
A rare cell with an arctic-alpine distribution. There is some variability in the number and configuration of the facial granules but the characteristic isthmial granules are always present. The Harris find was in an oligotrophic shallow loch.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands
West, W. & West, G.S. (1908) A Monograph of the British Desmidiaceae, Volume 3