Noteworthy Records of Three Usnea Species from the New York Adirondacks

The fruticose lichen genus Usnea, Old Man's Beard lichens, is well-recognized, charismatic and conspicuous, and readily detected during biodiversity surveys. As a result, the genus is well-represented in herbaria and the geographic ranges of the species are presumed to be thoroughly documented. During ecological fieldwork in the Adirondack Mountains of New York, however, we discovered three unexpected Usnea species. Here we report modern occurrences of two Usnea species previously known only from historical records in New York (U. ceratina and U. subfusca), the latter of which is a species of conservation concern. We also report U. subrubicunda, an eastern North American endemic, for the first time from New York state. Our records show that Usnea is more diverse than previously appreciated in intact and mature forest landscapes in the Adirondack Mountains and suggests that higher species richness may occur in similar habitats in other regions.