Distribution: N - Lomb. C - Tosc (Tretiach & al. 2008), Sar.
Description: Thallus crustose, endosubstratic or thinly episubstratic, whitish to pale grey, granulose, often poorly evident. Apothecia lirelliform, black, elongate, 0.5-1.5 x 0.2-0.3(-0.5) mm, epruinose, clearly raised, with a slit-like to slightly exapanded disc, at first isolated, but soon gathered into irregular to star-shaped, 2-3 mm wide, convex clusters. Proper exciple black, carbonized, extending below the hymenium; epithecium brown, c. 10 µm high; hymenium colourless, 70-100 µm high, I+ blue; paraphysoids 1.5-2 µm thick, the apical cells slightly swollen; subhymenium brownish, 25-35 µm high; hypothecium brown-black, carbonized. Asci 8-spored, cylindrical-clavate, fissitunicate, laterally thin-walled, the apex rounded, with a tholus and a small ocular chamber, within a K/I+ medium blue ring (the only amyloid part of the ascus wall), the ascoplasma K/I+ orange-brown. Ascospores 3-septate, hyaline, more or less club-shaped, thick-walled and with rectangular loculi, 15-20(-24) x 4-6 µm, without a distinct perispore, the wall thick, thickened at septa. Pycnidia black, semi-immersed. Conidia bacilliform, 5-7 x 1-1.2 µm. Photobiont trentepohlioid. Spot tests: thallus K- C-, KC-, P-. Chemistry: without lichen substances.
Note: a mild-temperate to Mediterranean-Macaronesian lichen of shaded siliceous rocks, mostly coastal; probably overlooked, or confused with other species in the past, but certainly not common.
Growth form: Crustose
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)