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, 3-15 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 5-10 mm wide; apices: rotund, crenate, ciliate; cilia: sparse, up to 2.0 mm long upper surface: gray with some blackened areas, smooth, dull to shiny, usually white maculate soredia: granular, common, in linear, marginal to submarginal soralia that often occur on revolute lobes; isidia and pustulae: absent medulla: white with continuous algal layer lower surface: black with brown to mottled white naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: not seen Pycnidia: occasional, punctiform conidia: filiform, 10-12 x 1 µm 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) and α-collatolic acid (± trace). Substrate and ecology: usually on trees in open habitats, rarely on rocks World distribution: SE U.S.A. and Mexico Sonoran distribution: Sonora, in the Sierra Madre Occidental.