Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: crustose, strongly rimose to areolate, 0.1-0.3 mm thick; prothallus: absent surface: yellowish white to dirty grayish yellow, pulverulaceous, dull, sorediate soredia: granular, 20-40 µm in diam., in yellowish to greenish white soralia up to 1.2 mm in diam. Apothecia: absent (not seen) or present, semi-immersed to sessile, slightly constricted at base, 0.7-1.6 mm in diam. disc: black to sometimes blackish brown (if damaged ?), plane to weakly convex, epruinose margin: thin, 0.05-0.075 mm wide exciple: hyaline to strongly black, or rarely greenish black, without algal cells parathecium: brown to reddish brown, sometimes with crystals epihymenium: bright green to blackish green, or rarely olive (if damaged ?) hymenium: hyaline to sometimes greenish hyaline, 50-80 µm tall, not inspersed; paraphyses: simple, rarely anastomosing or branched, slightly thickened apically hypothecium: brown to reddish brown asci: clavate, lecanoral, 8-spored ascospores: hyaline, simple, broadly ellipsoid to ovoid, 10-18 x 6-10 µm; wall: thick and smooth, not halonate Pycnidia: not seen Spot tests: thallus surface K+ yellow to rarely K-, C+ yellowish red, P+ yellow to rarely P- Secondary metabolites: 4,5-dichloro-3-O-methylnorlichexanthone, 4,5-dichloronorlichexanthone, arthothelin (2,4,5-trichloronorlichexanthone), asemone (=4,5,7-trichloronorlichexanthone), atranorin, chloroatranorin, thiophanic acid (=2,4,5,7-tetrachloronorlichexanthone), and thuringione (=2,4,5-trichloro-3-O-methylnorlichexanthone). Substrate and ecology: on non-calciferous rocks World distribution: Europe and North America Sonoran distribution: southern California in the Channel Islands.