Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 2-9 cm in diam., somewhat fragile, tightly adnate, subdichotomously lobate lobes: sublinear, elongate, plane to rugulose, 1-2 mm wide, initially separate, becoming contiguous to partly imbricate; margin: entire; apices: subtruncate upper surface: whitish gray, smooth, shiny, emaculate, isidia, soralia, pustulae and dactyls all absent medulla: white with continuous algal layer lower surface: black, tips brownish black; rhizines: frequent, black, sparsely dichotomous Apothecia: usually present, laminal, sessile, 1-5 mm in diam.; disc: brown, margin crenulate, lacking pruina, soredia or isidia asci: clavate, 8-spored ascospores: ellipsoid, 10-12 x 5-6 µm Pycnidia: peripheral on thallus, semi-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 4-O-methylphysodic and colensoic acids (major), hydroxycolensoic acid, lividic and methoxycolensoic acids (minor), oxyphysodic and physodic acids (trace). Substrate and ecology: on hardwood bark and rarely acidic rocks in lower montane to montane forests World distribution: neotropics and SE USA Sonoran distribution: Chihuahua in the Sierra Madre Occidental.