Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus distinctly orange to orange-yellow, occasionally with white or gray patches; chinky-areolate, smooth to rugulose, black or orange prothalli may be present; medulla usually I-. Apothecia usually abundant, sessile with broad base, to 2.5 mm broad; margin bare, smooth to crenulate, often flexuous on old apothecia; exciple of conglutinate branched hyphae radiating from hypothecium, lightly colored within, dark to margin; disk black, lightly to heavily pruinose; epithecium olive-brown to grayish, granulose; hymenium 75-120 μm; spores simple, hyaline, halonate, 14-24 X 6-11 μm.
Reactions: K— or K+ red; C—, P—, I— (usually).
Contents: Gowan (1989) lists four chemotypes: 1. with confluentic acid, and accessory 2'-0-methylperlatolic acid and other substances, 2. with norstictic and connorstictic acids, 3. with combination of 1 and 2, and 4, lacking substances.
This species grows on rocks in partial shade in the tundras, often in rock trains over hidden trickling water. It ranges from the high to low Arctic and is circumpolar, in North America ranging south in the East to Mt. Washington, New Hampshire, in the West to British Columbia.