The lichen genus Usnea in East Fennoscandia. III. The shrubby species

Nine shrubby Usnea species are reported from East Fennoscandia: Usnea diplo typus Vain., U. fulvoreagens (Rasanen) Rasanen, U. glabrata (Ach.) Vain., U . glabrescens (Nyl. ex Vain.) Vain. ex Rasanen, U. hirta (L.) F. H. Wigg., U. lapponica Vain., U. subfloridana Stirt., U substerilis Motyka and U. was muthii Rasanen. New chemotypes are reported in U. glabrescens, U. substeril is and U. wasmuthii. Some chemotypes have geographical tendencies in their distribution. For instance, the thamnolic acid strain of U. subfloridana is the main chemotype of the species only in some southern coastal regions. S everal poorly known taxa described especially by V. Rasanen are identified and lectotypified. A key to the shrubby Usnea species in East Fennoscandia is provided.