Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, circular in outline or irregularly spreading, up to 15 cm wide, loosely adnate, lobate lobes: flat to convex, irregular, loosely imbricate, mostly 0.5-2 mm wide, tips rounded, entire or weakly crenulate upper surface: ashy colored to whitish ochre (olive ochre in herbarium), dull or somewhat shiny, emaculate; pseudocyphellae irregularly punctiform to sublinear, up to 1.5 mm long and 0.05 mm wide, isidiate isidia: laminal to marginal, hemispherical initially, becoming dorsiventral, simple or branched; soredia absent upper cortex: paraplectenchymatous, c. 30 micrometer thick, composed of c. 4 layers, lumina up to 7 micrometer diam., pale brown to brown externally medulla: white, 85-150 micrometer thick, often with internal cephalodia lower cortex: c. 20 micrometer thick composed of 2-3 layers, pale brown lower surface: brown to brownish black centrally, densely ( up to 200 micrometer long) tomentose, moderately rhizinate; rhizines: simple, up to 2 mm long, pale brown initially and darkening with age Apothecia: rare, laminal, stipitate, up 3 mm diam., margin weakly lobate, often densely isidiate; disc: reddish to blackish brown; epithecium: reddish brown, c. 10 micrometer thick; hymenium: hyaline below, c. 100-120 micrometer thick, I+ blue; subhymenium pale brown, c. 20-30 micrometer thick; hypothecium colorless, c. 20 micrometer thick; paraphyses: simple, cylindrical, septate asci: obclavate, 8-spored ascospores: acicular, 7-septate at maturity, colorless, 90-105 x 8-9 micrometer Pycnidia: not seen Spot tests: upper surface K+ yellow, C-, KC-, P-; medulla K-, C-, KC+ rose, P- Secondary metabolites: cortex with pseudocyphellarin A; medulla with gyrophoric acid (major), 4-O-methyl gyrophoric acid (minor) and unknowns. Habitat and ecology: on bark or rock in very humid microclimates World distribution: central Mexico to Brazil, including the West Indies and Hawaii Sonoran distribution: Sierra Madre Occidental region of Sinaloa.