Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: indistinctly to distinctly crustose, continuous, strongly rimose, or sometimes irregularly areolate, up to 2 mm thick; prothallus: absent surface: chalky white, yellowish white to beige, dull, without soredia or isidia Apothecia: sessile to rarely semi-immersed, strongly constricted at base; 1.5-3 mm in diam. disc: black, plane to convex, epruinose margin: distinct, thin, lighter than thallus, sometimes with weakly whitish pruina exciple: bright green to bluish green, sometimes with few algal cells parathecium: hyaline, with crystals and/or oil droplets epihymenium: bright green to bluish green, rarely brown (if damaged ?) hymenium: hyaline, 65-110 µm tall, with oil droplets, rarely with crystals; paraphyses: simple, rarely anastomosing or branched, slightly thickened apically hypothecium: hyaline to rarely weakly brown, usually strongly filled with crystals, without oil droplets asci: clavate, lecanoral, 8-spored ascospores: hyaline, simple, broadly ellipsoid to ovoid, 10-17 x 6-10 µm; wall: thick and smooth, not halonate Pycnidia: globular, with Vobis-type III conidiophores conidia: filiform, strongly curved, 18-25 µm long Spot tests: thallus surface K- to K+ yellow, C- to very rarely C+ yellowish red, P- to P+ yellow Secondary metabolites: atranorin, hopane-6a,22-diol, and lichexanthone, rarely norlichexanthone, very rarely trichlorolichexanthone. Substrate and ecology: on non-calciferous or calciferous rocks World distribution: temperate parts of Africa, Asia, Europe, North and South America Sonoran distribution: at intermediate elevations in Arizona and Baja California.