Phylum: Charophytra   Family: Desmidiaceae

Cosmarium difficile var. subimpressulum Messikommer 1927

An apparently rare desmid found in mesotrophic acidic conditions such as moorland bogs. Because of its similarity with other cells its distribution is unclear.

References: 
Messikommer, E. (1927) Biologische Studien in Torfmoor von Tobenhausen unter besonderen Berüchsichtigung der Algen-vegetation.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.