Phylum: Charophyta Family: Desmidiaceae
Staurastrum paradoxum J. Ralfs 1848
First described and illustrated in Ralfs (1848: 138, fig. 23: 8a-f). Superficially similar to St. gracile, but stockier and with more robust terminal spines. Found with tri- and quadri-radiate forms, the latter being commonest and is stockier, presenting a different L/B ratio.
Cell dimensions: L: 31-42 µm; B: 38-59 µm.; Is: 7.5-12 µm.
The zygospores are multifaceted, presenting 4–6 angles in face view. The projections have furcate apices. Dimensions: minus projections: 22-25 µm; overall: 34-38 µm.
Common in the plankton of acidic lochs and moorland pools.
References:
Coesel, P.F.M. & Meesters, K.J. (2013) European Flora of the Desmid Genera Staurastrum and Staurodesmus.
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland.
Ralfs, J. (1848) The British Desmidieae.