Background and aims – The past few years, the limnoterrestrial and aquatic diatom flora of the entire Antarctic Region (sub-Antarctic islands, Maritime Antarctic Region, Antarctic Continent) is currently under revision. One of the genera that still needed a revision is the genus Eunotia, quite common in wet to semi-wet moss vegetations in the sub-Antarctic and Maritime Antarctic Region. Methods – Using both Light Microscopical and Scanning Electron Microscopical techniques, the morphology of all Eunotia taxa, present in the samples from the Antarctic Region, has been analysed. Each taxon is properly described, illustrated and compared with all other possible similar Eunotia taxa, known worldwide. Key results – A total of nineteen Eunotia taxa has been found of which one remains unidentified and is discussed as Eunotia sp. 1. Six taxa could be identified using the currently available literature: Eunotia meisterioides Lange-Bert., E. muscicola Krasske var. muscicola, E. paludosa Grunow var. paludosa, E. pyramidatoides, E. seminulum Nörpel-Schempp & Lange-Bert. and E. tecta Krasske. Ten new Eunotia species and two new subspecies are described: Eunotia amayae sp. nov., E. amayae subsp. heardensis subsp. nov., E. australomaior sp. nov., E. clotii sp. nov., E. frigida sp. nov., E. mcbridei sp. nov., E. mourotii sp. nov., E. muscicola subsp. polyglyphis subsp. nov., E. parallelogramma sp. nov., E. pseudopaludosa sp. nov., E. ralitsae sp. nov. and E. subantarctica sp. nov. Conclusions – The obtained results confirm the presence of a typical and highly specific limnoterrestrial diatom flora in the Antarctic Region and contradict the generally accepted idea about the worldwide distribution of diatoms.

ANTARCTIC REGION; BACILLARIOPHYTA; BIOGEOGRAPHY; EUNOTIA; MORPHOLOGY; NEW SPECIES; TAXONOMY