Distribution: N - Frl (TSB 12692), Ven (Lazzarin 2000b, Nascimbene & Caniglia 2003c, Nascimbene 2008, 2008c), TAA (Nascimbene 2006c, 2008b, Nascimbene & al. 2007b, 2008c, Nimis & al. 2015), Lomb, Piem, VA (Matteucci & al. 2008c), Emil (Nimis & al. 1996, Fariselli & al. 2020), Lig (Giordani & Incerti 2008). C - Tosc (Tretiach & Ganis 1999, van den Boom & Brand 2008), Marc (Nimis & Tretiach 1999), Abr (Nimis & Tretiach 1999), Laz (van den Boom & Brand 2008), Sar (Rizzi & al. 2011). S - Camp, Pugl, Cal (Puntillo 1996, Incerti & Nimis 2006).
Description: Thallus crustose, ecorticate, granulose, pale yellowish green to greenish ochre, without a distinct prothallus. Apothecia lecanorine, round or polygonal, often crowded, sessile with a weakly constricted base, 0.4-0.8(-1.2) mm across, with an orange- to red-brown, finally sometimes almost black, flat to slightly convex disc, and a weakly to strongly prominent, persistent or finally excluded, smooth to slightly crenulate thalline margin which is often slightly paler and more yellowish than thallus. Epithecium olivaceous green to red-brown, with granules soluble in K, reacting N-; hymenium colourless or with orange-brown granular patches, 40-65 µm high; paraphyses sparingly branched and anastomosing, apically thickened; hypothecium colourless or pale yellowish brown. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, narrowly ellipsoid, often slightly bent or deformed, (6.5-)8-12(-15) x (3-)4-5.5 µm. Pycnidia semi-immersed to immersed, with a pale brown wall, colourless to pigmented in upper psrt. Conidia of three types: 1) broadly fusiform to curved, 6-9 x 1.5-2.5 µm produced into 60-110 µm wide macropygnidia (the most common): 2) slightly curved, 8-11 x c. 1 µm; 3) bacilliform, 3-5 x 2-2.5 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC- or KC+ pale yellow, P-, UV-. Chemistry: isousnic acid and neousnic acids, traces of atranorin and zeorin.
Note: a holarctic, temperate to boreal-montane lichen found on hard, undecomposed wood or on acid bark (conifers, Betula, etc.); most frequent in the Alps, but also present in the mountains of southern Italy.