Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 4-10 cm in diam., adnate to loosely adnate, subdichotomously lobate lobes: sublinear, elongate, convex, 0.5-2 mm wide, contiguous to somewhat imbricate; margin: entire; apices: subtruncate to subrotund, often convex upper surface: whitish gray, smooth, shiny; pruina and maculae absent; isidia, soredia, pustulae and dactyls all absent medulla: white with continuous algal layer lower surface: black, tips brownish black; rhizines: sparse, black, dichotomous Apothecia: usually present, laminal, substipitate, 2-8 mm diam.; disc: blackish brown; margin: smooth to crenulate asci: clavate, 8-spored ascospores: ellipsoid, 11-12 x 5-6 µm Pycnidia: marginal, immersed conidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C-, KC+ red, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with α-collatolic and alectoronic acids (major), ß-alectoronic (minor). Substrate and ecology: on acidic rocks in open habitats lower montane to montane forests World distribution: throughout the neotropics Sonoran distribution: Sinaloa in the Sierra Madre Occidental.