Thallus: foliose, loosely adnate, 3-20 cm in diam., lobate lobes: subirregular, elongate, slightly imbricate, plane, separate, 8-12 mm wide; apices: rotund, becoming crenate and dissected with age, ciliate; cilia: up to 2.5 mm long upper surface: yellow green, smooth, dull, epruinose, emaculate, finely reticulately cracked with age isidia: simple to coralloid branched, often apically ciliate, common, initially laminal but becoming submarginal to marginal with age; soredia and pustulae: absent medulla: pale orange yellow with continuous algal layer lower surface: black with brown naked zone peripherally, centrally rhizinate; rhizines: simple Apothecia: not seen Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P-; medulla K-, C-, KC+ red or KC-, P- Secondary metabolites: upper cortex with usnic acid (major) atranorin (trace); medulla with protolichesterinic acid (major). Substrate and ecology: trees or rocks in open habitats World distribution: pantropical and southern Africa Sonoran distribution: oak and pine forests of the Sierra Madre Occidental in Sinaloa.