Distribution: C - Sar (Egea & al. 1993, Egea & Torrente 1994).
Description: Thallus crustose, episubstratic, white, rimose-areolate, farinose-granulose, up to 230 μm thick but sometimes poorly developed, ecorticate, with a cretaceous medulla. Apothecia round, irregular or lirelliform, 0.7-1.8 x 0.4-1 mm, simple or sparingly branched when lirelliform, immersed to adnate, black but usually white-pruinose, with a flat to slightly convex disc, and a thin, entire to wavy proper margin. Proper exciple black, extending below the hymenium; epithecium brownish; hymenium colourless, 55-75 μm high, I+ reddish; paraphysoids richly branched and anastomosing, up to 1.5 μm thick, the apical cells hardly swollen; subhymenium pale brown, 12-15 μm high; hypothecium black to brown-black. Asci 8-spored, cylindrical-clavate, thick-walled, fissitunicate, with a thin K/I+ pale blue tholus and a small ocular chamber with an inconspicuous amyloid ring. Ascospores 5-7-septate, hyaline, spindle-shaped, straight or slightly curved, (18-)20-26 x 3.5-5 μm, the wall slightly thickened at septa, with a thick gelatinous perispore. Pycnidia black, immersed. Conidia straight to slightly curved, 5-7 x 1.2-1.5 μm. Photobiont trentepohlioid. Spot tests: thallus K-, C-, KC-, P+ orange. Chemisrty: psoromic and conpsoromic acids, sometimes confluentic acid, plus an unidentified substance.
Note: a species known from the coasts of the Mediterranean Region, from Portugal to Tunisia, found beneath overhangs of coastal siliceous rocks protected against salt-spray.