Atti Soc. ital. Sci. nat. (Modena) 11: 165 (1868).

Synonyms: Index Fungorum

Protolog: Data lacking.

Type locality: Data lacking.

Type locality coordinates: Data lacking.

Molecular barcode: Data lacking.

Thallus: determinate or rarely indeterminate, orbicular, with effigurate margin, up to 7 cm wide, areolate towards the center. Areoles less than 3 mm wide, the margin with 2-3 rounded lobes per areole, lobes 0.1-0.5 mm wide. Upper surface glossy or dull varying from pale yellow brown to mahogany with black tones. Upper and lateral cortices paraplectenchymatous, 40-50(-100) µm thick; cells: (3-)5-6 µm wide, sometimes opaque in water; syncortex: sometimes with visible periclinal hyphae, 4-30 µm thick; eucortex: reddish-brown upper layer 5-20 µm thick, lower portion hyaline and 15-40 µm thick. The algal layer is + even, algal cells +arranged in vertical colums with strands sometimes extending into medulla. The medulla white, often obscure, intricately prosoplectenchymatous, continuous with attaching hyphae. Apothecia usually one per areole, up to 2 mm across; disc immersed, dark brown to black, flat, rough, epruinose, sometimes with inter-ascal plectenchyma forming surface of minute umbos, sometimes with parathecial crown. Hymenium hyaline, 90-150 µm high. Epihymenium pale to dark brown. Parathecium usually wide, 70-50 µm thick around the disc, often forming parathecial crown, narrowing beneath apothecium. Paraphyses 1.0-2.0 µm wide at mid-level, apices +expanded to 4-5 µm. Asci 60-100 x 15-28 µm, clavate. Ascospores usually about 100 spores per ascus, usually narrowly ellipsoid but various, mostly 4.0-5.1 x 1.5-2.0 µm (Knudsen et al. 2008: 5).

Chemistry: Spot tests: cortex KC+ red (a yellowish pigment diffuses from this and several other brown species in K). Gyrophoric acid (major), lecanoric acid (minor), + 3-hydroxygyrophoric acid (trace), + methyl lecanorate (trace) (Knudsen et al. 2008: 5).

Ecology: Saxicolous, on a steep rock. Santesson (2004: 11). On acid and volcanic rocks, on calcareous rock in open situations from above 500 meters (Knudsen 2008: 5).

Molecular data: Genbank

Distribution: Europe, Asia, western North America, Argentina, Chile. Database

Note: