Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Squamules: up to 8 mm wide, rounded, adnate and dispersed to adjacent or partly imbricate, weakly concave to weakly or strongly convex upper surface: gray to olivaceous brown, dull, epruinose or partly to entirely pruinose, strongly fissured margin: concolorous with upper side or white, straight, entire or crenulate upper cortex: up to 140 µm thick, composed of thin-walled hyphae with round lumina, containing crystals of lichen substances and calcium oxalate medulla: containing calcium oxalate lower cortex: absent or poorly developed lower surface: white to pale brown Apothecia: up to 2 mm diam., marginal, immarginate even when young, black, epruinose or white pruinose ascospores: ellipsoid, 10-17 x 6-8 µm Pycnidia: laminal, immersed conidia: bacilliform, 5-7 x 1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow; medulla K-, C-, KC-, P- Secondary metabolites: atranorin, sometimes trace of norstictic acid. Substrate and ecology: on soil in open habitats at 1740-2130 m World distribution: western North America Sonoran distribution: locally fairly common in northern Arizona.