Distribution: N - Lomb. S - Camp, Bas (Puntillo & al. 2012), Si (Grillo & Caniglia 2004).
Description: Thallus crustose, episubstratic, thin to rather thick, soft, farinose, pinkish white (the pink colour fades in the herbarium), often inapparent in epiphytic samples. Apothecia arthonioid, round to rarely ellipsoid, up to 0.8-1 x 0.5 mm, with a flat to slightly convex, black, epruinose disc, without a distinct proper margin. Epithecium dark brown, K+ pale green; hymenium pale reddish brown, 30-40 µm high; paraphysoids c. 1-1.5 µm thick at mid-level, the apical cells often with a brown cap; hypothecium dark brown to black. Asci 8-spored, broadly clavate, semi-fissitunicate, with a large apical dome and a distinct ocular chamber, Arthonia-type. Ascospores (1-)3(-4)-septate, hyaline, clavate, with one of the end cells distinctly enlarged, 11-17 x 4-6 µm. Pycnidia rare, black, immersed. Conidia straight, c. 7 x 2 µm. Photobiont trentepohlioid. Spot tests: thallus K-, C-, KC- P-. Chemistry: without lichen substances.
Note: a southern species, known from Europe and North America, found on acidic rocks and exposed roots in dry underhangs, also on dry undersides of trees in sheltered, humid situations, such as in forests.
Growth form: Crustose
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)