Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, loosely adnate, 3-10 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 6-12 mm wide; apices: rotund, crenate, ascending, ciliate; cilia: up to 4 mm long upper surface: gray with some blackened areas, smooth, dull, sometimes white pruinose, usually white maculate isidia: simple to coralloid, common, laminal to submarginal; tips: sometimes ciliate, becoming eroded and subsorediate; soredia and pustulae: absent medulla: white with patches of yellow to orange brown, particularly in lower layers, continuous algal layer lower surface: black with brown to tan or mottled white naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: rare, substi ascospores: broadly ellipsoid, 16-22 x 10-14 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P-; medulla K-, C-, KC+ red or orange, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with alectoronic acid (major), α-collatolic acid (minor) and skyrin (accessory). Substrate and ecology: usually on trees in open habitats, rarely on rocks World distribution: pantropical and southern USA Sonoran distribution: Sonora and Sinaloa, in the Sierra Madre Occidental.