Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, adnate to loosely adnate, 3-15 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 8-15 mm wide; apices: rotund, ciliate; cilia: sparse, 0.3-2.0 mm long upper surface: gray with some blackened areas, smooth, dull to shiny, sometimes white pruinose, usually white maculate soredia: granular, common, in linear, marginal to submarginal soralia; isidia and pustulae: absent medulla: white with continuous algal layer lower surface: black with brown to mottled white naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: not seen Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P-; medulla K+ yellow turning orange, C-, KC-, P+ orange Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with stictic acid (major) and constictic and norstictic acids (minor). Substrate and ecology: usually on trees in open habitats, rarely on rocks World distribution: pantropical and pantemperate Sonoran distribution: southern, coastal regions of California and the western fringe of Baja California.