Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: foliose, 3-9 cm in diam., tightly adnate, subdichotomously lobate lobes: sublinear, elongate, plane to subconvex, separate and becoming somewhat imbricate, 1-4 mm wide; apices: subtruncate, plane upper surface: tannish gray, smooth but becoming rugose with age, shiny, pruina and maculae absent dactyls: inflated, tips often breaking open (appearing superficially sorediate or isidiate within); isidia absent medulla: white with continuous algal layer lower surface: black with peripherally brown tips; rhizines: abundant but not at margins, black; dichotomous Apothecia: rare, laminal, substipitate, 1-4 mm in diam.; disc: brown; margin: smooth to crenulate asci: clavate, 8-spored ascospores: ellipsoid, 9-13 x 5-7 µm Pycnidia: 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 4-O-demethylphysodic and colensoic acids (major), hydroxycolensoic acid, lividic and methoxycolensoic acids (minor), oxyphysodic and physodic acids (trace). Substrate and ecology: on bark in oak and pine forests of montane regions World distribution: across the neotropics and extending into SW USA Sonoran distribution: SE and E Arizona and south along the Sierra Madre Occidental into Chihuahua and Sinaloa.