Phylum: Charophyta Family: Desmidiaceae
Cosmarium laeve Rabenhorst 1868
Rabenhorst's original description is rather brief and sketchy, which has led to confused interpretations and spawned many varieties, creating a rather confused complex. Kouwets (in manuscript) is attempting to bring some order by describing new species. This Haclait find may well end up as C. laeviforme.
References:
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.