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

Thallus: foliose, 5-15 cm in diam., often coriaceous, loosely adnate, subdichotomously lobate lobes: sublinear, elongate, initially separate, becoming slightly imbricate, 2-6 mm wide; margin: entire; apices: subtruncate, plane to subconvex upper surface: gray, plane to convex, smooth to shallowly rugulose, dull, somewhat pruinose towards tips, strongly white maculate; isidia, soredia, pustulae and dactyls all absent but secondary lacinae sometimes developing centrally medulla: white with continuous algal layer lower surface: black, somewhat shiny; rhizines: dense, black, dichotomous Apothecia: common, laminal, sessile to substipitate, 2-10 mm in diam.; disc: brown; margin: crenulate asci: clavate, 8-spored ascospores: ellipsoid, 12-16 x 6-9 µm Pycnidia: 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 barbatic and 4-O demethylbarbatic acids (major). Substrate and ecology: on rocks, soil and bark in oak and pine forests World distribution: throughout the neotropics, including the Carribean, and also in SE Asia Sonoran distribution: fairly common in the Sierra Madre Occidental in Chihuahua.