Thallus: foliose, adnate to loosely adnate, 3-15 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 4-20 mm wide; apices: rotund, sometimes deeply crenate, elacinate, ciliate; cilia: sparse to frequent, 0.3-2.0 mm long upper surface: gray, smooth, dull, emaculate soredia: granular, common, in linear, submarginal soralia that are often on lateral, subascending lobes; isidia and pustulae: absent medulla: white with continuous algal layer lower surface: black with brown naked zone peripherally, centrally rhizinate; rhizines: scattered, simple Apothecia: very rare, substipitate, up to 7 mm in diam.; margin: sparsely sorediate; disc: brown, imperforate ascospores: ellipsoid, 22-30 x 13-15 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P-; 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 in open habitats, rarely on rocks World distribution: pantropical and pantemperate Sonoran distribution: southern California, Baja California Sur and Sonora.