Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose to subcaespitose, very loosely adnate, up to 13 (-19) cm across, dichotomously or subdichotomously lobate lobes: 1-2 (-3) mm broad, strongly to moderately involute or occasionally nearly flat; apices: ciliate; cilia: sparse to moderately abundant, up to 2.5 mm long, usually simple upper suface: pale gray; not sorediate or isidiate lower surface: black or brownish colored at the tips of the lobes or pale throughout with darker zones here and there, smooth and slightly wrinkled, very rarely with a few short scattered rhizines Apothecia: abundant, 3-10 mm diam. asci: clavate, 8-spored ascospores: ellipsoid to reniform, (14-) 16-22 x (6-) 8-10 µm Pycnidia: abundant, 0.1-0.2 mm diam., immersed conidia: bacilliform, straight, 6-7 x 1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow; medulla K+ yellow then red, C-, P+ orange Secondary metabolites: cortex with atranorin and chloroatranorin; medulla with salazinic acid (major), norstictic and consalazinic acids (minor) and a fatty acid. Substrate and ecology: common on trees and relatively rare on rocks World distribution: common only in Mexico Sonoran distribution: Sierra Madre Occidental of Sinaloa.