Fruticose and Foliose Lichens of the High-Mountain Areas of the Southern Appalachians

Abstract

The high-mountain ascomycetous lichen flora of the spruce-fir zone of the southern Appalachian Mountains of North Carolina, Tennessee and southwestern Virginia [USA] includes 178 fruticose and foliose species in 37 genera and 20 families, of which 7 (4% of the spp.) are endemic to the Appalachian Mountains and 18 (10%) occur in North America north of Mexico, essentially only in the Appalachians, but are disjunct elsewhere as in Japan, Mexico or the American tropics. The overall distribution patterns of these lichens, which share phytogeographic relationships with both northern and southern floristic elements, support existing evidence that the southern Appalachians served as a refugium during the Tertiary Era. The continuously more moist, cooler climate characteristic of the higher elevations favors the maintenance of lichens restricted in North America north of Mexico to high-mountain areas of the southern Appalachians. Usnea confusa Asah., previously known only from Japan, is new to North America and Parmelia producta comb. nov. [Hypotrachyna producta Hale] is presented as a new combination. The secondary natural product chemistry and keys to families, genera and species of high-mountain fruticose and foliose lichens are provided.