Phylum: Charophyta   Family: Closteriaceae

Closterium striolatum J. Ralfs 1848

A common species that needs to be compared closely with Cl. costatum. As the name suggests, it’s markedly striate with usually 6-8 striae per 10 µm.
Cell dimensions: L: 270-410 µm; B: 30-45 µm; Ap: 8.5-12 µm; L/B: 8-10.
One of the commonest and widespread species in acidic waters. This can range from mildly to greatly acidic such as ditches, loch-margins and moorland peaty pools.

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.