Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, areolate, up to 1 mm thick; prothallus: absent or present, black, rarely as thin margin of single areoles visible areoles: strongly bullate, contiguous, 0.2-0.4 mm wide surface: grayish to yellowish white to white, dull or weakly glossy, without soredia or isidia Apothecia: sessile, slightly to strongly constricted at base, 0.4-1 mm in diam. disc: black, plane to weakly to strongly convex, epruinose margin: indistinct or distinct, c. 0.05 mm thick, becoming excluded exciple: hyaline or strongly greenish black, without algal cells parathecium: reddish brown, sometimes with crystals epihymenium: green to blackish green hymenium: hyaline, 50-70 µm tall, sometimes partly green, not inspersed; paraphyses: simple, rarely anastomosing or branched, slightly thickened apically hypothecium: reddish brown asci: clavate, lecanoral, 8-spored ascospores: hyaline, simple, broadly ellipsoid, 10-16 x 6-9 µm; wall: thick and smooth, not halonate Pycnidia: not seen Spot tests: thallus surface K- to rarely K+ yellow, C+ yellowish red, P- to rarely P+ yellow Secondary metabolites: 2,5,7-trichloro-3-O-methylnorlichexanthone, 3-O-methylasemone (=4,5,7-trichloro-3-O-methylnorlichexanthone), 3-O-methylthiophanic acid (=2,4,5,7tetrachloro-3-O-methylnorlichexanthone), 5,7-dichloro3-O-methylnorlichexanthone, atranorin, chloroatranorin, isoarthothelin (=2,5,7-trichloronorlichexanthone), and thiophanic acid (=2,4,5,7-tetrachloronorlichexanthone). Substrate and ecology: on non-calciferous rocks World distribution: Africa, and temperate parts of Asia, Europe, North and South America Sonoran distribution: central and eastern Arizona.