NOTES ON THE GENUS USNEA DILL EX ADANSON

Usnea quercina Bystrek & Gorzynska, based on heterogeneous type materi al, is lectotypified and becomes a synonym of U. wirthii P. Clerc. Usn ea wirthii is new for South America. A distribution map of U. madeiren sis Motyka (Syn. U. silesiaca Motyka) in Europe is given. Usnea hesper ina Motyka (Syn. U. elongata Motyka, U, schadenbergiana Gopp & Stein, U. subgracilis Vain., U. subplicata (Vain.) Motyka) is new for Africa, Asia and South America. Usnea hirta (L.) F. H. Wigg. (Syn. U. corruga ta Motyka, U. foveata Vain., U. leprosa Motyka) is new for Africa. Usn ea subscabrosa Nyl. ex Motyka (Syn. U. santae-annae Motyka) is new for South America. The holotype of U. marocana Motyka (=U. mutabilis Stir t.) was found in LBL. (C) 1997 The British Lichen Society.