Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus whitish, very thin, subgranulose to subsquamulose, K—. Apothecia adnate, flat to slightly convex; margin thick, of same color as disk or slightly paler, orange-red or yellowish brown; exciple brownish yellow; disk to 2 mm broad, dull, epruinose, orange-red to yellowish brown; hypothecium hyaline, less than 60 µm high; epihymenium yellowish, K+ violet; hymenium 80-100 µm, hyaline; paraphyses septate, slender, tips not capitate, 2.0-2.5 µm, covered with a thick granular episamma; spores 8, polari-locular, hyaline, ellipsoid, 14-23 x 7-13 µm, septum 1-2 µm.
This species grows over moss, humus, and soil. It is circumpolar arctic-alpine, in North America ranging south to Colorado and Washington.
Somewhat similar is Caloplaca livida (Hepp) Jatta, which has shorter spores, 13-15 x 6.5-8 µm, a broader septum, 2.5-3.5 /xm, the exciple and hypothecium 1+ blue. It is a central European and Scandinavian species recently reported from both eastern and western Greenland (Hansen, Poelt, & S0chting 1987) and may possibly turn up in North America.