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, 3-10 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 8-15 mm wide; apices: rotund, subascending, eciliate or short cilia developing in the axils of the lobes upper surface: gray with some blackened areas, smooth, usually shiny, emaculate, reticulately cracked with age soredia: granular, common, in linear to subcapitate, marginal soralia that sometimes develop on marginal lacinae; isidia and pustulae: absent medulla: white with continuous algal layer lower surface: black with brown naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: rare, substipitate, up to 5 mm in diam.; margin: sparsely sorediate; disc: brown, imperforate ascospores: ellipsoid, 18-22 x 8-10 µm Pycnidia: rare, punctiform, conidia: sublageniform, 6-7 x 1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P-; medulla K-, C-, KC-, P+ red Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with protocetraric acid (major), unknown fatty acid (major, minor or ± trace). Substrate and ecology: usually on trees in open habitats World distribution: pantropical Sonoran distribution: southern lowlands of Sonora, Baja California del Sur.