Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, loosely adnate to adnate, 3-15 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 8-15 mm wide (very variable); margin: becoming dentate lacinate with age; lacinae: 5-10 x 1-2 mm; apices: rotund, ciliate; cilia: sparse, simple, up to 2.0 mm long upper surface: ashy white to gray, smooth, dull, strongly reticulate maculate, becoming reticulately cracked with age along the maculae; soredia, isidia and pustulae absent medulla: white with continuous algal layer lower surface: black with narrow brown zone peripherally, rhizinate to margin or narrowly erhizinate marginally; rhizines: scattered, simple to squarrosely branched Apothecia: common, substipitate, up to 10 mm in diam.; margin: rugose, white maculate; disc: often perforate, concave or flat ascospores: simple, hyaline, ellipsoid, 13-15 x 7-9 Pycnidia: common marginally conidia: filiform, 10-14 x 1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow; medulla K+ yellow turning deep red, C-, KC-, P+ orange Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with salazinic acid (major) and consalazinic acids (minor). Substrate and ecology: usually on trees World distribution: pansubtropical and pantemperate; common especially in SE USA and South Africa Sonoran distribution: SE Arizona and adjacent Sierra Madre Occidental of Chihuahua, Sonoran and Sinaloa.