Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, up to 5 cm in diam., irregular to somewhat orbicular lobes: mostly irregular-flabellate, ± contiguous to slightly overlapping, 0.8-2 mm broad, ± flat at the tips but often becoming somewhat convex inwardly surface: gray to gray-brown, usually with a ± complete pruina sorediate: the soredia primarily in marginal and terminal soralia on lateral lobes, becoming labriform, scattered punctiform laminal soralia sometimes forming in older thallus parts; individual soredia coarsely granular, mostly becoming distinctly darkened, to almost black upper cortex: prosoplectenchymatous, irregularly so in parts medulla: white lower cortex: very thin, poorly organized to weakly prosoplectenchymatous, intergrading with the medulla lower surface: almost white on the lobe tips, inward becoming pale tan to deep tan; rhizines scattered, simple to irregularly furcate, concolorous with the lower surface Apothecia: not seen Pycnidia: infrequent, dark brown to blackened and flush with the surface conidia: cylindrical (a few becoming slightly curved), 5-6 x 1 µm Spot tests: all negative for both cortex and medulla Secondary metabolites: small amounts of unidentified terpenoids (2 or 3). Substrate and ecology: rock or very thin soil or mosses over rock, in open areas World distribution: western North America and central Asia. Sonoran distribution: northern half of Arizona, in the mountains