Phylum: Charophyta   Family: Desmidiaceae

Micrasterias truncata var. semiradiata (C. Nägeli) F. Wolle 1884

Coesel & Meesters (2023: 110) note: “Cells in outline almost circular. Apices slightly domed. Sinus as well as the incision between the lobes wider open than in the nominate variety.”
Cell dimensions: L: 93-112 µm; B: 93-109 µm; Is: 19-22 µm; L/B: 0.98-1.08.
Found in acidic mesotrophic waters such as moorland pools and abandoned peat-cuttings. This is the commonest of the varieties.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition). Desmids of the Lowlands.