Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: continuous, thin, loose in texture surface: gray-yellow or gray- to brown-green, ±warted or wrinkled, without cracks soralia: present, discrete, contiguous or fused, punctiform, c. 0.2 mm diam., convex, green-yellow, of loosely arranged soredia Apothecia: up to 0.3 mm in diam., sessile disc: brown to dark red-brown, at a very early stage almost flat but soon becoming convex, without pruina margin: at first distinct, level with disc, soon excluded and reflexed, concolorous with disc proper exciple: without crystals, ±olive-brown (K-, N-), pale green (K-, N+ purple), or a mixture of both along rim and sometimes also in upper part, other parts paler epithecium: ± blue-green (K-, N+ purple), ± olive-brown (K-, N-), or a mixture of both; crystals: absent hymenium: 40-55 µm tall, colorless below; paraphyses: 1.5-2 µm wide in mid-hymenium; apices: mostly ±clavate or some not at all thickened, 1.5-3 µm wide hypothecium: colorless asci: clavate, 8-spored ascospores: ±acicular, spirally coiled, 20-40 x 2-3 µm, 3-7-septate Pycnidia: not observed Spot tests: K-, C+ pink, at least in squash preparations of soredia, KC-, P- Secondary metabolites: gyrophoric acid. Habitat and ecology: on smooth bark of Quercus agrifolia in open forests at c. 500 m; in other areas of the world, widespread in polluted areas on smooth bark with occasional finds on rock World distribution: North America and Europe Sonoran distribution: known from two closely situated localities in the Santa Ynez Mountains west of Santa Barbara, southern California.