Phylum: Charophyta   Family: Desmidiacea

Cosmarium alteroreniforme F.A.C. Kouwets 2025

This form is distinguished by the reniforme semicells being elevated. It is rather similar to a form depicted by Coesel (1979: 391, pl. 17: 5) and a form depicted by Van Westen (2024: 439 as morpha b).
Cell dimensions: L: 53-63 µm; B: 48-56 µm; Is: 15-18 µm; Th: c.28 µm; L/B: 1.02-1.20.
Of the few records currently known, it would seem to enjoy neutral to slightly alkaline mesotrophic waters.

References: 
Coesel, P.F.M. (1979). Desmids of the broads area of N.W.-Overijssel (The Netherlands) II.
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium.