Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, adnate to loosely adnate, 3-20 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 8-15 mm wide; apices: rotund, margin becoming dentate lacinate with age; lacinae: 5-10 x 1-2 mm; margin: ciliate; cilia: sparse, up to 4.0 mm long upper surface: ashy white to gray, smooth, dull to rather shiny, emaculate to white maculate, becoming reticulately cracked with age; soredia, isidia and pustulae: absent medulla: white, with continuous algal layer lower surface: black with brown naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: common, substipitate, up to 15 mm in diam.; margin: rugose, white maculate; disc: brown, often perforate ascospores: broadly ellipsoid, 9-16 x 6-10 Pycnidia: common conidia: bacilliform to short-filiform, 8-10 x 1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P-; medulla K+ yellow turning deep red, C-, KC-, P+ orange Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with salazinic acid (major) and consalazinic acids (minor). Substrate and ecology: usually on trees and rocks in open habitats in canyons at intermediate elevations World distribution: Mexico and SW U.S.A. Sonoran distribution: SE Arizona and adjacent Sierra Madre Occidental of Chihuahua, Sonoran and Sinaloa and southern Baja California Sur.