Diatoms of Europe, Volume 6 discusses 419 taxa of the family Eunotiaceae, including synonyms. Eunotia belongs to the most prominent and species-richest diatom genera, and is rather homogenous compared to other large genera. Restriction to freshwater of almost exclusively oligosaprobic habitats is a unique ecological feature of this genus which probably ranks 3rd at present after Nitzschia and Pinnularia in continental waters.
Eunotia species play an important role as bio-indicators for water monitoring. The samples have been collected around Europe, including the European part of Russia, and from Greenland, the Arcticm and the Macaronesian Islands. The current research revealed 105 established and 54 new Eunotia taxa including four that have recently been published separately. Moreover eight taxa new to science originate from other subcontinents of the Holarctic. Detailed determination keys that correspond to the illustrations will help to identify European and corresponding American taxa successfully.