Phylum: Charophyta   Family: Desmidiaceae

Staurodesmus phimus (W.B.Turner) K. Thomasson 1959

First described and illustrated by Turner (1893: 136, pl. 12: 9) as Arthrodesmus phimus. It was later moved to its current genus by Thomasson (1959: 75).
Cell dimensions: L: 19-26 µm; B: 20-25 µm; Is: 6-7 µm; Sp: 4-8 µm; Overall LxB: 27-31 x 28-30.
A rare taxon found in acidic conditions such as moorland pools and bogs. West & West (1912: 104) note: “The typical form of this species is not known to occur in the British Islands.”

References: 
Coesel, P.F.M. & Meesters, K.J. (2013). European Flora of the Desmid Genera Staurastrum and Staurodesmus.
Thomasson, K. (1959). Nahuel Huapi: plankton of some lakes in an Argentina National Park with notes on terrestrial vegetation.
Turner, W.B. (1893). Algae aquae dulcis Indiae orientalis. The freshwater algae (principally Desmidieae) of East India.
Van Westen, M. (2024). Sieralgen in Drenthe.
West, W. & West, G.S. (1912). A Monograph of the British Desmidiaceae, Volume 4.