Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: placodioid, clearly forming rosettes, 2-3 cm wide, loosely adnate, lobate peripherally lobes: convex often folded, up to 5 mm long, and 0.5-1.5 mm wide upper surface: bright yellow to golden yellow, smooth to somewhat rugulose upper cortex: 10-20 µm thick medulla: yellow throughout, inspersed with yellow granules lower cortex: 20-30 µm thick under lobes but absent centrally lower surface: yellow peripherally but becoming pale yellow centrally; hapters: sometimes present, stout, peripheral Apothecia: occasional, sessile, up to 1.4 mm wide; margin: smooth, becoming crenulate with age, occasionally lobulate; disc: darker yellow than the thallus; epithecium: c. 5 µm thick; hymenium: c. 50-65 µm tall; paraphyses: simple, cylindrical or with somewhat swollen, up to 3 µm wide tips; hypothecium: c. 70-90 µm thick asci: clavate, 8-spored ascospores: narrowly ellipsoid to weakly kidney-shaped, (9-) 11-16.5 x 3.5-5 µm Pycnidia: frequent, spherical to broadly ellipsoid, immersed or appearing as raised warts on the thallus surface conidia: narrowly ellipsoid, 2-3 x 1.5 µm Spot tests: upper surface K+ reddish C-, KC-, P-; medulla K+ reddish, C-, KC-, P- Secondary metabolite: calycin. Substrate and ecology: on calcium free rocks and boulders in open montane habitats World distribution: northern South America to southwestern USA Sonoran distribution: relatively rare but conspicuous, extending from 1000 m. to at least 2200 m. in the foothills and mountains of Arizona, Chihuahua, Sonora and Baja California Sur.