Description: Thallus crustose, episubstratic, grey-green to brown, continuous to granular and composed of goniocysts surrounded by hyphal cells with a papillate wall. Perithecia 0.1-0.25 mm across (in section), more or less globose, sometimes slightly barrel-shaped, 2/3 immersed to almost entirely superficial, grey-brown when young, later usually black, but paler around the ostiole, the surface smooth, not glossy. Exciple 2-layered, pigmented in outer part, colourless and of compressed cells within; involucrellum absent; hamathecium of periphysoids which soon dissolve into a poorly differentiated hymenial gel (interascal filaments in mature ascomata lacking). Asci 8-spored, clavate, thin-walled, fissitunicate, not or very weakly thickened above, I-, K/I-. Ascospores muriform, hyaline, ellipsoid, (25-)29-35(-45) x 10-16 μm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate species with subtropical affinities found on ancient deciduous trees, in crevices or amongst mosses, often at the base of trunks, in undisturbed forests or in deep gorges of the submediterranean belt; to be looked for further in Tyrrhenian Italy. The species is included in the Italian red list of epiphytic lichens as “Vulnerable” (Nascimbene & al. 2013c).
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)