Phylum: Charophyta   Family: Desmidiaceae

Cosmarium magnificum var. italicum M. Raciborski 1889

This variety differs from the nominate in the less well-developed central swelling and with slightly smaller dimensions.
Single cell dimensions: L: 104 µm; B: 78 µm; Is: 30 µm; Th: 53 µm; L/B: 1.34.
A rare taxon found in slightly acidic oligo-mesotrophic waters.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.