Abstract
Korean folk medicine 'ORiNaMu' has been used mainly to cure toothache and alcoholism. With regard to the botanical origin of 'ORiNaMu', it has been considered to designate the branch of Alnus species (Betulaceae), but there was no pharmacognostical confirmation on it. To clarify the botanical origin of 'ORiNaMu', the anatomical characteristics of the branch of Alnus firma, A. hirsuta, A. japonica and A. maximowiczii were studied. As a result, it was found the morphological criteria for the four Alnus species that could discriminate them the number of cork cell layer, fiber, stone cell and diameter of vessel. According to there criteria, it was clarified that the commercial folk medicine 'ORiNaMu' was the branch of Alnus firma.