Phylum: Charophyta   Family: Desmidiaceae

Haplotaenium minutum (J. Ralfs) T. Bando 1988

First described and illustrated by Ralfs (1848: 158, pl. 26: 5) as Docidium minutum. Much later Bando (1988: 176) moved it to Haplotaenium. The similar Haplotaenium rectum is generally slightly larger in length and has a small, but discernible basal inflation.
Cell dimensions: L: 80-180 µm; B: 7-18 µm; L/B: 8-13.
Infrequently recorded in moorland pools and disused peat-cuttings.

References: 
Bando, T. (1988) Haplotaenium, a new genus separated from Pleurotaenium (Desmidiaceae, Chlorophyta).
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
Ralfs, J. (1848) The British Desmidieae.
Ruzicka, J. (1977) Die Desmidiaceen Mitteleuropas, Volume 1, Part 1.