Phylum: Charophyta Family: Desmidiaceae
Cosmarium horizontale (Schmidle) Kouwets 1997
A smaller, but distinct, version of Cosmarium bisphaericum var. densegranulatum, which is also associated with the doubtful C. excavatum f. duplo-maius (see Kouwets 1997, p.44). Both species enjoy the same habitat-type and have been found together in the same loch. They are also similar in being rarely encountered. The Harris finds have been confirmed by Frans Kouwets.
Kouwets, F.A.C. (1997) Contributions to the Knowledge of the French Desmid Flora I. New and Noteworthy Taxa from the Central and Eastern Pyrenees
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium