SYNOPSIS OF THE GENUS USNEA (LICHENIZED ASCOMYCETES) IN BRITISH-COLUMBIA, CANADA

Twenty-three Usnea species and species groups are reported from Britis h Columbia, Canada. Usnea chaetophora, U. diplotypus, and U. nidulans s. lat. are new to North America, whereas U. esperantiana and U. rigid a s. lat. are documented for the first time for Canada, and U. ceratin a and U. rubicunda are new to British Columbia. New chemotypes are als o reported, e.g., in U. gragilescens var. mollis and U. subfloridana. Usnea stuppea (a synonym of U. substerilis) is lectotypified. A key to the genus Usnea in British Columbia is provided.