Phylum: Charophyta   Family: Closteriaceae

Closterium turgidum J. Ralfs 1848

First described in Ralfs (1848: 165, pl. 27: 3) and illustrated by Jenner.
Cell dimensions: L: 700-810 µm; B: 59-80 µm; Ap: 14-18 µm; L/B: 10-11.
A large cell found mainly in acidic moorland pools and bogs, especially with Sphagnum. Said to be widespread in suitable habitats but proving to be quite scarce in the Outer Hebrides.

References: 
Brook, A.J. & Williamson, D.B. (2010). A Monograph on some British Desmids.
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. (1904). A Monograph of the British Desmidiaceae, Volume 1.