Distribution: N - Ven (Caniglia & al. 1999, Nascimbene & Caniglia 2000, Nascimbene 2008c), TAA (Nascimbene & Caniglia 2002c, Nascimbene & al. 2006e, 2007b, 2009, Nimis & al. 2015), Lomb (Nascimbene & al. 2006e), Piem (Griselli & al. 2003, Piervittori 2003). C - Tosc (Loppi & al. 1994, 1995), Abr (Nimis & Tretiach 1999), Mol (Nimis & Tretiach 1999, Caporale & al. 2008), Sar (Zedda 2002, 2002b, Zedda & Sipman 2001). S - Cal (van den Boom & Brand 2008).
Description: Thallus crustose, endosubstratic or thinly episubstratic, granulose or warted-areolate, pale grey, greenish grey or brownish. Areoles irregular in outline, slightly to strongly convex, contiguous. Apothecia lecanorine when young, later turning almost biatorine, round to slightly irregular in outline, sometimes densely crowded, sessile and constricted at base, 0.3-0.7(-0.9) mm across, with a dark grey, dark brown to brown-black, rarely reddish brown, flat to slightly convex, usually epruinose disc, and a paler, weakly prominent, more or less persistent, rarely totally excluded thalline margin. Thalline exciple with algae mostly concentrated at the base, laterally 25-35 µm wide, basally 25-100 µm wide; proper exciple greenish brown or ochre and N+ violet in outer part, colourless to pale brown within, of radiating hyphae; epithecium greenish brown, dark brown, green or almost black, K+ red-violet, without a layer of granules; hymenium colourless, 30-35 µm high, without brown granules; paraphyses sparingly branched and anastomosing, the apical cells dark green; hypothecium colourless, 40-85 µm high. Asci 8-spored, clavate with an I+ blue tholus containing a I- or I+ much lighter blue, broad and tapering axial body. Ascospores 1-celled (rarely a few 1-septate), hyaline, narrowly ellipsoid, 7-14 x 2.5-5 µm. Pycnidia black, semi immersed. Conidia ellipsoid, 3-3.5 x 1.2-1.5 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: thallus with paraensic acid; apothecia with the Cinereorufa-green pigment.
Note: a boreal-montane lichen found on hard lignum, especially on decorticated stumps, more rarely on the acid bark of conifers and of Castanea, mostly in upland areas.