Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: flat to bullate or squamulose areolate; prothallus: indistinguishable to conspicuous, black, black-green areoles: contiguous to dispersed, flat to highly convex, squamiform, subbullate to bullate, up to 2.5 mm in diam.; regular to irregular, angular to round in outline upper surface: shiny, (usually) pale brown to (more rarely) dark reddish brown in the center of areoles and with a small , whitish, grayish or blackish margin, esorediate cortex: consisting of 3 layers: (a) a 5-30 µm thick, indistinctly to distinctly lammelated, unpigmented, translucent epinecrotic layer, medulla: white, I+ intensely violet; algal layer: 60-90 µm thick lower surface: dark (only to be seen in some squamulous specimens) Apothecia: black, with a slightly to moderately constricted base, up to disc: black, flat to convex, epuinose or faintly bluish pruinose margin: black, usually persistent, dull to shiny exciple: with a greenish black, epihymenium-like rim, unpigmented inside epihymenium: bright green (cinereorufa-green), olive green to green-brown, 8-15 µm thick hymenium: hyaline, 40-55 µm tall, I+ blue; paraphyses: simple, occasionally scarcely branched and anastomosing subhymenium: hyaline, 20-40 µm thick hypothecium: hyaline to medium brown asci: clavate, 40-65 x 13-16 µm, 8-spored ascospores: hyaline, simple, ellipsoid-oblong, mean values: 7-11 x 3.2-4.5 µm Pycnidia: immersed, graphidoid conidia: bacilliform to cylindrical, +straight, (10-)11.5-15(-18) x 1.2 µm [studied in 20 specimens] Spot tests: cortex and medulla K-, C-, KC-, P- Secondary metabolites: schizopeltic acid.