Phylum: Charophyta   Family: Desmidiaceae

Micrasterias jenneri J. Ralfs 1848

First described and illustrated by Ralfs (1848: 76, pl. 11: 1). West & West (1905: 86, pl. 43: 1-2) suggest it is scarce.
Cell dimensions: L: 150-180 µm; B: 100-130 µm; Is: 24-34 µm; L/B: 1.35-1.50.
Infrequently recorded. Found in upland areas, with Sphagnum in particular.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
Ralfs, J. (1848) The British Desmidieae.
West, W. & West, G.S. (1905) A Monograph of the British Desmidiaceae, Volume 2.