Phylum: Charophyta   Family: Closteriaceae

Closterium dianae var. brevius (S. Petkoff) W. Krieger 1935

It differs from the nominate in being shorter and broader, mainly due to its tumidity.
Cell dimensions: L: 156-180 µm; B: 19-20.2 µm; Ap: 2.8-4 µm; Arc: 92-117°; L/B: 8-9.
There are few records of this variety which is thought to be rare in Britain. An acidophile of moorland bogs and pools.

References: 
Brook, A.J. & Williamson, D.B. (2010). A Monograph on some British Desmids.
Van Westen, M. (2024). Sieralgen in Drenthe.