Phylum: Charophyta Family: Desmidiaceae
Micrasterias truncata var. crenata (J. Ralfs) R. Grönblad 1920
First described and illustrated in Ralfs (1848: 75, pl. 7: 2 & pl. 10: 4) as Micrasterias crenata. It was later moved by Grönblad (1920: 39) to a variety of M. truncata. Slightly smaller than the nominate with rounded polar and upper lateral lobes, although intermediates exist.
Cell dimensions: L: 75-125 µm; B: 60-100 µm; Is: 15-20 µm; L/B: 1.10-1.20.
Found in acidic mesotrophic waters such as moorland pools and abandoned peat-cuttings. Rarely encountered.
References:
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
Grönblad, R. (1920) Finnländische Desmidiaceen aus Keuru.
Ralfs, J. (1848) The British Desmidieae.
Ruzicka, J. (1981) Die Desmidiaceen Mitteleuropas, Volume 1, Part 2.
West, W. & West, G.S. (1905) A Monograph of the British Desmidiaceae, Volume 2.