substrate: soil, clay, humus, turf, detritus, dead leaves | bryophytes mosses, liverworts | rock, stones, pebbles unspecified.
Thompson, J., 1984. American Arctic Lichens: The Macrolichens.
Thallus foliose, loosely attached to the substratum, dichotomously to irregularly branched, the lobes elongate as compared to Xanthoparmelia centrifuga; upper side yellow, brownish in spots, often chinky separated crosswise, smooth to wrinkled; underside mouse gray or dove gray to black, smooth with sparse simple rhizinae, medulla white. Apothecia adnate, slightly pedicillate; margin entire to lobulate, concolorous with the thallus; disk concave, to 8 mm broad, bright chestnut brown, shining, epruinose; cortex of amphithecium poorly differentiated, heavily in-spersed with yellow granules and opaque, the surface rough; epithecium and upper 12 μ of hymenium clear brown; lower part of hymenium hyaline; hymenium 65 μ, I+ blue; hypothecium 90 μ, hyaline to yellowish or grayish yellow, the upper 25 μ 1+ violet, no reaction in the lower part; paraphyses conglutinate, thick-walled, little branched, septate, the tip cells enlarged, brown to 4 μ; asci clavate, 30 x 12 μ; spores 8, hyaline, elongate ellipsoid, simple, 10-12.5x 4.5-6.5 μ.
Contents: usnic acid, alectoronic acid, and atranorin.
This species grows over mosses, on humus, and on rocks. It is probably circumpolar, arctic, ranging from Novaya Zemlya, across Siberia and northern North America, but has not yet been found in Greenland.