Rock gnome lichen

"Endemic to the southern Appalachian mountains of North Carolina and Tennessee, the endangered rock gnome lichen is known to colonize where little else might thrive. It inhabits rock faces in high elevations where fog provides the moisture it needs or in river gorges that are cool and damp. The hearty little fungus also absorbs minerals and pollutants in rain, enabling biologists to determine various kinds of pollution . . . Too much pollution, however, continues to pose a threat to remaining rock gnome lichen populations. In recent years, airborne pollution and the impacts of an exotic insect have contributed to a dramatic decline in the spruce-fir forests adjacent to the cliffs and rock outcrops occupied by the lichen. This may lead to the drying up of sites that are otherwise moist, which the lichen prefers. Lichens are also impacted by recreational disturbances from hikers and rock climbers that frequent the Appalachian Mountains and trample on the sensitive colonies."