Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 4-12 cm in diam., adnate to tightly adnate, subdichotomously lobate lobes: sublinear to subirregular, somewhat elongate, initially separate, becoming slightly imbricate, concave or plane, 1-2 mm wide, margin: entire; apices: subtruncate, plane upper surface: whitish gray, smooth, shiny, white maculate; isidia, soredia, pustulae and dactyls all absent medulla: white with continuous algal layer lower surface: black, rhizines: dense, black, dichotomous Apothecia: abundant, laminal, substipitate, 2-20 mm in diam.; disc: brown; margin: crenulate and white maculate asci: clavate, 8-spored ascospores: ellipsoid, 10-13 x 6-7 µm Pycnidia: marginal or submarginal, immersed conidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C + red, KC + red, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with evernic and lecanoric acids (both major). Substrate and ecology: on hardwood bark, particularly smooth barked Quercus species, in montane and upper montane forests World distribution: neotropics and extending into adjacent temperate areas Sonoran distribution: SE and E Arizona and S along the Sierra Madre Occidental in Sonora, Chihuahua and Sinaloa and the mountains of southern Baja California Sur. Notes: Particularly in SE Arizona and the northern part of the Sierra Madre Occidental this species is the most common Hypotrachyna at mid-elevations.