Phylum: Charophyta Family: Desmidiaceae
Cosmarium sphaeroideum West 1892
An infrequently found species with the British population seemingly confined to the granitic regions of Scotland and Ireland. An acidophile largely confined to moorland bogs. Similar to Cosmarium amoenum but that species is a little smaller, especially in breadth with a higher L/B: ratio.
References:
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium
West, W. & West, G.S. (1908) A Monograph of the British Desmidiaceae, Volume 3
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands