Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 3-15 cm diam., adnate to loosely adnate, subdichotomously lobate lobes: sublinear, elongate, plane, separate, becoming partially imbricate, 1.5-4 mm wide; apices: subtruncate to truncate upper surface: whitish gray (tan in herbarium with age), smooth, shiny; usually strongly white maculate isidia: laminal to marginal, dense, cylindrical, simple to coralloid branched, slender, rarely becoming lobulate, concolorous with the thallus but tips sometimes blackened; soralia, pustulae and dactyls absent medulla: white with continuous algal layer lower surface: black, peripherally brownish black, shiny; rhizines: dense, black, dichotomous Apothecia: rare, laminal, sessile, 2-10 mm in diam.; disc: brown; margin: crenulate, without isidia asci: clavate, 8-spored ascospores: broadly ellipsoid, 11-16 x 7-10 µm Pycnidia: marginal, immersed conidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C+ yellow-orange, KC + yellow-orange, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with 4-O-demethylbarbatic and barbatic acids (both major), obtusatic and norobtusatic acids (both minor to trace). Substrate and ecology: on bark of many different trees in lower to upper montane forests World distribution: neotropical, Oceania, SE Asia and Australasia Sonoran distribution: Sierra Madre Occidental in Sinaloa.