Background and aims – 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 thorough analysis is the genus Halamphora, recently split off from Amphora . Halamphora species are a typical constituent of the lake diatom flora in the Antarctic region. Methods – Using both Light Microscopical (LM) and Scanning Electron Microscopical (SEM) techniques, the morphology of a large number of Halamphora taxa, present in the samples from the Antarctic Region, has been analysed. Each taxon is properly described, illustrated and compared with other morphologically similar Halamphora taxa, known worldwide. Key results – A total of seven Halamphora taxa has been found. Two taxa could be identified using the currently available literature: Halamphora veneta (Kütz.) Levkov and H. oligotraphenta (Lange-Bert.) Levkov. Five new Halamphora species are described: Halamphora ausloosiana Van de Vijver & Kopalová sp. nov., H. compereana Van de Vijver & Levkov sp. nov., H. dagmarobbelsiana Van de Vijver & Levkov sp. nov., H. lateantarctica Van de Vijver, Kopalová, Zidarova & Levkov sp. nov. and H. vyvermaniana Van de Vijver, Kopalová, Zidarova & Levkov 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; HALAMPHORA; MORPHOLOGY; NEW SPECIES; TAXONOMY