Parmelia skultii

Parmelia skultii is a species of terricolous and saxicolous (soil- and rock-dwelling) foliose lichen in the family Parmeliaceae. Described from Alaska in 1987, this lichen is primarily a high-latitude species of the North Pacific–Arctic region, occurring from the Aleutian Islands through Alaska and across to Greenland, Svalbard, and Russia, with a disjunct population discovered in Montana's Bitterroot Range extending its range about 2,500 km southward. The species forms fragile rosette-shaped growths 6–10 cm across, typically growing among mosses or on rocks in windswept locations, and is distinguished by its broader lobes with marginal pores, a white frosty coating that often develops with age, and its distinctive chemistry that includes norstictic acid—features that help separate it from the related Parmelia omphalodes....read more on Wikipedia.