In the present paper, the morphology and taxonomy of seven desmid taxa collected in various European habitats is discussed, mainly on the basis of scanning electron microscopic observations of cell wall sculpturing. Four taxa (Actinotaenium riethii, Closterium pseudocostatum, Cosmarium discrepans and C. hostensiense) are newly described and the name of one taxon (Cosmarium lenzenwegeri) is recombined.
In addition, the morphology of Cosmarium cataractarum and C. cinctutum is described in greater detail, confirming their status as independent species.