Distribution: N - Frl (TSB 20607), Ven (Lazzarin 2000b, Nascimbene & Caniglia 2003c), TAA (Nascimbene & al. 2006e, 2007b, Nimis & al. 2015, van den Boom & Brand 2008), Lomb, Piem (Isocrono & al. 2004).
Description: Thallus crustose, endosubstratic to thinly episubstratic, continuous to areolate-verrucose, grey, grey-brown or pale yellowish brown, without a distinct prothallus, forming patches to 4 cm in diam. Apotecia lecanorine, broadly appressed to sessile, 0.25-0.7 mm across, with a flat to strongly convex, pale yellowish brown to bluish-grey or finally black, often whitish-pruinose disc, and a thin, persistent, only initially prominent, smooth or crenulate thalline margin concolorous with thallus or with disc. Thalline exciple corticate, the upper part brown, the algal layer reaching the upper surface, with granules arranged in anticlinal rows; proper exciple reddish brown to bluish green in outer part; epithecium yellowish brown, olive-brown or rarely dark brown, N+ red-violet, with small and large (1-5 µm), colourless granules; hymenium colourless in lower part, reddish brown to blue-grey in upper part, 35-45 µm high; paraphyses simple to sparingly branched, 1-2 µm thick, not ot slightly widened in upper part; hypothecium colourless. Asci 8-spored, clavate, Lecanora-type. Ascospores 1-celled to 1-septate, hyaline, ellipsoid, 8-10 x 3-4 µm. Micropycnidia rare; microconidia bacilliform, 4-5.7 µm long. Mesopycnidia common, immersed, pale brown around the ostiole; mesocondia ellipsoid, 2.7-4 x c. 1.7 µm. Leptopycnidia very rare; leptoconidia slightly to strongly curved, c. 19 x 0.7 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC+ yellow, P- or P+ pale yellow. Chemistry: pseudoplacodiolic acid (major), placodiolic acid (trace), usnic acid (trace).
Note: a poorly known taxon of the L. symmicta complex, found on acid bark, most often of conifers, and on lignum, mostly in upland areas. The record from Mt. Vesuvius by Aprile & al. (2002), being dubious, is not accepted here.