Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 3-10 cm in diam., closely adnate, dichotomously lobate lobes: sublinear, elongate, plane to subconvex, separate to contiguous, 1-3 mm wide; margin: entire to subcrenate; apices: subtruncate to subrotund, plane to convex upper surface: light gray, gray to yellowish gray, smooth to somewhat rugulose, dull but shiny in younger lobes, irregularly cracked in older lobes, emaculate, epruinose soredia: farinose to slightly granular, in mostly subterminal, capitate soralia; isidia, pustules and dactyls absent medulla: white with continuous algal layer lower surface: black centrally, brown peripherally; rhizines: sparse to moderate, black, dichotomous Apothecia: rare, laminal, substipitate, 2-3 mm diam.; disc: dark brown; margin: sorediate asci: clavate, 8-spored ascospores: broadly ellipsoid, 9-11 x 5-7 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C+ red, KC+ red, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with olivetoric acid (major). Substrate and ecology: on bark of hardwoods and pines in montane and upper montane forests World distribution: neotropics (Columbia to Mexico), South Africa and Australasia Sonoran distribution: Baja California (Cedros Island).