Phylum: Charophyta   Family: Desmidiaceae

Euastrum gayanum G.B. De Toni 1889

Semicells sub-rectangular, sinus narrow and closed, basal angle rounded, sides from the basal angle divergent to a sub-lobe, from there to the apical angle concave. Apex truncate and bilobed with a shallow and wide notch. Lobes and angles papillate. In the centre of the semicell is a protuberance plus granulation within the periphery.
Cell dimensions: L: 11-16 µm; B: 10-13.5 µm; Is: 3-4.5 µm; Th: 6-7.5 µm; L/B: 1.10-1.25.
Widespread and common in acidic, mesotrophic habitats such as moorland pools and bogs.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
De Toni, G.B. (1889) Sylloge algarum omnium hucusque cognitarum. Vol. I. Chlorophyceae.