Phylum: Charophyta   Family: Closteriaceae

Closterium closterioides  (Ralfs) A. Louis & Peeters

An acidophile of moorland bogs. Widespread but not common

References: 
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids
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