Phylum: Charophyta Family: Closteriaciaea
Closterium angustatum var. gracilius Croasdale 1955
A very rare Arctic and northern species first discovered by Croasdale (1955) in Alaska. A few subsequent finds are from Sutherland, Scotland. It differs from the nominate variety by being significantly narrower. An acidophile of Sphagnum bogs and moorland peaty pools.
Croasdale, H.T. (1955) Freshwater algae of Alaska. 1. Some desmids from the interior.
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids.