Phylum: Charophyta   Family: Desmidiaceae

Cosmarium crenatum  Ralfs ex Ralfs 1848

Cosmarium crenatum is a very confused species complex. Kouwets (in manuscript) has provided a detail account and more research from good populations is required.

References: 
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.