Phylum: Charophyta   Family: Closteriaceae

Closterium nematodes var. proboscideum W.B. Turner 1893

The nominate variety is not known in Europe and is thought to be an entirely tropical species. It differs in having more striations per 10 µm. The main identification character of var. proboscideum is the thickening of the cell-wall just below the apices.
Single cell dimensions: L: 317 µm; B: 41 µm; Is: 7.7 µm; Arc: 103°; L/B: 8.
Rare in acidic habitats such as moorland pools and bogs. Brook & Williamson (2010: 318) only record two sites in north-west Scotland.

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.