Phylum: Charophyta   Family: Desmidiaceae

Staurodesmus dickiei (J. Ralfs) S. Lillieroth 1950

First described and illustrated by Ralfs (1848: 123, pl. 21: 3 a-b) as Staurastrum dickiei. It was later moved to its current genus by (Lillieroth 1950: 264).
Cell dimensions: L: 25-36 µm; B: 26-36 µm; Is: 7.5-9.5 µm; Sp: 3.4-6 µm.
Recorded as widespread and locally common in Europe. West, West & Carter (1923: 3, as Staurastrum dickiei) suggest it is generally distributed over Scotland and go on to say: “… is a most ubiquitous Desmid and frequently occurs in great abundance in gatherings from bogs and marshes.” It is proving to be rather scarce in the Outer Hebrides.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013). European Flora of the Desmid Genera Staurastrum and Staurodesmus.
Lillieroth, S. (1950). Über Folgen kulturbedingter Wasserstandsenkungen für Makrophyten- und Planktongemeinschaften in seichten Seen des südschwedischen Oligotrophiegebietes. Eins Studie mit besonderer Berücksichtigung der angewandten Limnologie.
Ralfs, J. (1848). The British Desmidieae.
West, W., West, G.S. & Carter, N. (1923). A Monograph of the British Desmidiaceae, Volume 5.