Phylum: Charophyta   Family: Closteriaceae

Closterium setaceum Ehrenberg ex Ralfs 1848

West & West (1904: p. 190, pl. 26: 9-13) describe it as widespread but much rarer than Cl. kuetzingii. It is more slender and has fewer pyrenoids (usually 3 per chloroplast). Found in nutrient-poor lochs in the marginal vegetation.

References: 
Ralfs, J. (1848) The British Desmidieae.
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids.
West, W. & West, G.S. (1904) A Monograph of the British Desmidiaceae, Volume 1.
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands.