Phylum: Charophyta   Family: Closteriaceae

Closterium lineatum var. elongatum (Rosa) Croasdale 1955

First described by Rosa (1951: 200, pl. 6: 3) as Closterium lineatum f. elongatum. It was later raised to a variety by Croasdale (1955: 525, pl. 8: 11). Similar in all respect to the nominate variety but with narrower cells which are usually less than 20 µm.
Cell dimensions: L: 330-650 µm; B: 22-35 µm; Ap: 6.5-8 µm; L/B: 15-22.
Found in Sphagnum bogs, lochans and disused peat-cuttings. A scarce desmid but can be locally abundant.

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.
Croasdale, H.T. (1955). Freshwater algae of Alaska. 1. Some desmids from the interior.
Rosa, K. (1951). Algenflora von Südböhmen. I. Die Algen der Umbegung von Blatná.