Rhizocarpon geographicum ? and Umbilicaria hyperborea ?
Lichens covering a horizontal surface of a large piece of quartz. The crustose lichen with a dark gray base and light gray to yellow-tinged spots may be a type of map lichen, Rhizocarpon geographicum ? while the dark ashy-gray foliose lichen at the center may be Umbilicaria hyperborea ? Photographed atop Camp Ridge, to the north of Camp Denali, Denali National Park and Preserve....................September 8, 2009.