Distribution: N - Ven, TAA (Nascimbene & al. 2007b, 2022), Lomb, Lig (Giordani & Incerti 2008). C - Tosc, Marc (Nimis & Tretiach 1999), Umb (Ravera 2000, Ravera & al. 2006), Laz (Ravera 2001, Massari & Ravera 2002), Abr (Nimis & Tretiach 1999), Sar (Zedda 2002, Rizzi & al. 2011, Cossu 2013, Di Nuzzo & al. 2022). S - Camp (Aprile & al. 2003b), Pugl (Nimis & Tretiach 1999), Bas (Ravera & al. 2015d), Cal (Puntillo 1996, Incerti & Nimis 2006), Si (Ottonello & al. 2011).
Description: Thallus crustose, often minutely granular (granules 15-70 µm in diam.), pale to dark grey-brown, greenish white, or grey-green, sometimes poorly evident. Apothecia biatorine, broadly adnate or slightly constricted at base, 0.2-0.6(-0.8) mm across, with a concave to slightly convex, reddish brown (when dry) to black (when wet), epruinose disc, and a concolorous or darker, rather thick, finally sometimes excluded proper margin. Proper exciple dark brown to violet-red in outer part, colourless to pale brown within, of radiating, conglutinated hyphae with ellipsoid to oblong lumina; epithecium pale yellow to brown, K-, N-; hymenium colourless, 55-75 µm high, I+ blue; paraphyses simple or sparingly branched in lower part, rather lax, 0.8-1 µm thick at mid-level, the apical cells 2-4 µm wide, often with a brown cap; hypothecium colourless or pale brown, K-. Asci 8-spored, subcylindrical, with a K/I+ blue outer coat and a K/I+ uniformly blue apical dome, approaching the Catillaria-type, but with a non-amyloid axial mass and a small ocular chamber, with biseriately arranged spores. Ascospores 1-septate, often slightly constricted at septum, hyaline, ellipsoid or oblong-ellipsoid, 9-15 x 5-7 µm, with a smooth wall surrounded by an up to 1.5 µm thick, gelatinous perispore. Photobiont chlorococcoid ( Dictyochloropsis), the cells 5-9 µm in diam. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate to subtropical lichen found on trunks of old broad-leaved trees, often in parts which are seldom wetted by rain, or on undersides of thick branches; locally common in some humid areas of southern Italy.
Growth form: Crustose
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)