Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.

Life habit: lichenized Thallus: crustose, placodioid, continuous, forming rosettes, effigurate lobes: radiating, but sometimes irregular, discrete or confluent; tips: usually rotund or ±truncate, eciliate upper surface: whitish gray to glaucous gray, leaden to bluish gray, ±plane to convex or concave towards the periphery, shiny or dull, usually epruinose but often pruinose at the blackish lobe tips; with or without soralia, without pustules, isidia or pseudocyphellae upper cortex: pseudoparenchymatous, formed by vertically arranged hyphae, filled with many minute crystals not dissolving in K medulla: usually white or faintly yellow to mustard colored photobionts: primary one a chlorococcoid Trebouxia, 9-14 µm in diam., secondary photobiont absent lower cortex: absent lower surface: usually pale tan to pale pink, attachrf by medullary hyphae and without rhizines, cyphellae, pseudocyphellae and tomentum Ascomata: apothecial, rare, without a thalline margin, laminal on thallus, orbicular, first covered by the thallus, later sessile disc: black or brown-black, epruinose; thalline exciple: absent; epihymenium: brown-black, granular, K-; hypothecium: generally brown or brown-black asci: lecanoral, apex wall layers thickened, apex I+ blue, with distinct axial body, 8-spored ascospores: brown, one-septate, ellipsoid, thick-walled (intermediate type between mischoblastiomorphic and Physcia-type), 9-15 x 4-8 µm Conidiomata: usually present, pycnidial, laminal, when fully developed immersed in the thallus conidia: colorless, simple, ±bacilliform, formed acrogenously, conidiophore-type V (Vobis 1980), 4-5 x 0.8-1 µm Secondary metabolites: upper cortex atranorin (often accompanied by chloroatranorin), medulla with diploicin (major), gyrophoric acid (major or minor), dechlorodiploicin (minor), isofulgidin (minor), dechloro-O-methyldiploicin (minor or trace), buellolide (minor), canesolide (minor or trace), secalonic acids A, B and C (minor or trace) Geography: predominately atlantic-subatlantic temperate Europe, Mediterranean region, Africa, Hawaii, Australia, New Zealand, Japan, and western North America Substrate: mostly bark, wood, rock walls, acidic and calcareous rocks in nutrient-enriched sheltered as well as open habitats.