The study contains detailed researches on epiphytes of Populus tremula in in Antalieptė oak forest (Gražutė regional park, Zarasai district, Lithuania). Upper and lower parts, southern and northern exposition of trees were examined. 62 phrorophytes were examined, 43 taxa of epiphytic lichens, 28 taxa of epiphytic mosses and 4 taxa algae were found on them. Dominant epiphytic lichen species were Plyctis argena, Lecanora argentata, dominant bryophyte species were Radula complanata, Hypnum cupressiforme, and Plagiommnium cuspidatum. Pachyphiale fagicola was found first time in Lithuania.
Keywords: lichens, bryophytes, algae, epiphytes, Populus tremula, regional park, Lithuania.