Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: adnate to loosely adnate, foliose, 4-20 cm in diam., irregularly lobate lobes: subirregular, elongate, plane to subconvex, separate, 2-8 mm wide, lobulate or not; apices rotund, crenate, eciliate upper surface: yellow green to pale yellow, smooth but becoming rugose with age, dull to slightly shiny, epruinose and emaculate; soralia, isidia, and pustulae absent medulla: white and occasionally yellow patches, with continuous algal layer lower surface: black centrally, brown peripherally; rhizines sparse, black, simple Apothecia: common, up to 8 mm wide, laminal on thallus, sessile; disc: cinnamon-brown to dark brown, epuinose; margin: smooth asci: clavate, 8-spored ascospores: simple, ellipsoid, hyaline, 12-20 x 7-11 µm Pycnidia: common, immersed conidia: bacilliform, 7-8 x 1 µm Spot tests: upper cortex K-, C-, KC+ yellow, P-; medulla K-, C-, KC-, P+ red Secondary metabolites: upper cortex with usnic acid (major) and atranorin (accessory), medulla with protocetraric acid (major), caperatic acid (minor), secalonic acid A (accessory). Substrate and ecology: bark of shrubs and small trees in open habitats World distribution: North and South America, Texas to Argentina; Australasia Sonoran distribution: arid woodlands in foothills of the Sierra Madre Occidental in Sinaloa.