Phylum: Charophyta   Family: Closteriaceae

Closterium kuetzingii  Brébisson 1856

A common species of mainly acidic waters where it can be found in marginal vegetation and also with Sphagnum. Very similar to Closterium setaceum although that species tends to be more slender and has fewer pyrenoids.

References: 
Brébisson, L. A. de (1856) Liste des Desmidiées, observées en Basse-Normandie.
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids.
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands.
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland.