Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: adnate, foliose, 4-16 cm in diam., lobate lobes: sublinear, contiguous to imbricate, elongate, plane, separate, 1-4 mm wide, rather brittle, apices truncate upper surface: gray to yellowish gray, smooth to foveolate, shiny or dull, sometimes white pruinose, becoming cracked along prominent, effigurate pseudocyphellae soredia: coarse to subisidiose, abundant, yellowish, commonly marginal; isidia and pustulae absent medulla: white with continuous algal layer lower surface: black centrally, brown peripherally, rhizinate, rhizines moderately dense, black, simple to furcate Apothecia: rare, laminal, 2-4 mm wide; margin: usually sorediate; disc: dark brown asci: clavate, 8-spored ascospores: ellipsoid, 10-12 x 5-6 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC- (or + orange if usnic acid in high concentration), P+ orange; medulla K+ yellow turning deep red, C-, KC-, P+ yellow Secondary metabolites: upper cortex with atranorin and chloroatranorin and accessory usnic acid (in the soralia); medulla with salazinic acid (major), consalazinic and protolichesterinic acids (both minor). Substrate and ecology: frequent on exposed rocks World distribution: boreal to arctic regions in North American and Europe Sonoran distribution: only known from one scree slope in the upper part of the Chiricahua Mountains, SE Arizona.