Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 2-6 (-8) cm in diam., tightly adnate to adnate, subdichotomously lobate lobes: sublinear to subirregular, short, often imbricate, irregularly branched; plane to subconvex, 1-5 mm wide; margin: entire, rarely incised; apices: subtruncate to rotund upper surface: light gray, smooth to rugulose, dull, frequently white pruinose (especially marginally), emaculate soredia: initially farinose but becoming coarse and granular, in subcapitate, laminal to subterminal soralia but becoming diffuse; pustulae, isidia and dactyls all absent medulla: white with continuous algal layer lower surface: black centrally, blackish brown tips; rhizines: sparse to dense, black, dichotomous Apothecia: rare, laminal, sessile, 1-5 mm in diam.; disc: brown; margin: smooth, sometimes sorediate asci: clavate, 8-spored ascospores: ellipsoid, 6-8 x 3-4 µm Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K+ yellow, turning deep red; C-, KC-, P+ orange Secondary metabolites: upper cortex atranorin and chloroatranorin; medulla with salazinic acid (major), consalazinic acid (minor), norstictic acid (trace). Substrate and ecology: usually on wood and bark in humid forests, occasionally on rocks, in montane to subalpine forests World distribution: pantropical and extending to temperate parts of Argentina and Chile Sonoran distribution: Sinaloa in the Sierra Madre Occidental.