Phylum: Charophyta   Family: Closteriaceae

Closterium directum  W. Archer 1862

A widespread and common species of peaty pools and moorland bogs, especially with Sphagnum. Particularly common in the north-west of Scotland.

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.