Distribution: N - Frl (TSB 15093), Lig. C - Tosc. S - Si (Nimis & al. 1994, Ottonello & Puntillo 1995).
Description: Thallus crustose, very thinly episubstratic, continuous, greenish, yellowish white or brownish, somehow glossy, sometimes limited by a dark prothalline line. Apothecia black, epruinose, at first ellipsoid, then lirelliform, sometimes with furcate apices, straight to flexuose, 1-2(-3.5) x 0.3-0.5 mm, usually isolated, with a slit-like disc and an inflexed proper margin. Proper exciple prosoplectenchymatous, brown-black, extending below the hymenium; epithecium brown; hymenium colourless or pale yellow, 80-120 µm high, K/I-, I+ reddish; paraphyses thread-like, sparingly branched and anastomosing; hypothecium brown-black. Asci (6-)-8 spored, elongate-clavate, the apical thickening with an internal beak, K/I- . Ascospores 1(-3)-septate, slightly constricted at septum, with subequal cells, at first hyaline then pale brown, 13-18 x 4-6 µm. Pycnidia black, semi-immersed. Conidia bacilliform, 3-4 x c. 1 µm. Photobiont trentepohlioid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate species found on more or less smooth bark, especially of Fraxinus ornus. It is included in the Italian red list of epiphytic lichens as “Vulnerable” (Nascimbene & al. 2013c).