Thallus: adnate, foliose, 2-8 cm in diam., fragile, irregularly lobate lobes: sublinear, moderately imbricate, elongate, plane to subconvex, separate, 0.5-1.5 mm wide; apices: subrotund, sometimes dissected, ciliate; cilia: dense, bulbate, sometimes branched isidia: laminal, dense, cylindrical, simple to coralloid, sometimes darkened apically; soredia and pustulae absent upper cortex: pale gray, smooth to rugose, shiny, faintly or distinctly white maculate medulla: white, with continuous algal layer lower cortex: black centrally, pale marginally, densely rhizinate; rhizines, branched, black to medium brown Apothecia: rare, laminal, 1-2 mm wide, sessile to subpedicellate; disc: red-brown to dark brown; margin: outer rim usually isidiate, inner rim ecoronate, ascospores: ellipsoid, 8-10 x 4-6 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow; medulla K-, C+ red, KC+ red, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with gyrophoric acid (major). Substrate and ecology: on small trees in open habitats World distribution: pantropical and extending into subtropics Sonoran distribution: oak forests at intermediate elevations in Sonora.