Distribution: N - TAA (Nascimbene & al. 2007b), Emil (Nimis & al. 1996, Fariselli & al. 2020), Lig. C - Mol (Nimis & Tretiach 1999, Caporale & al. 2008), Sar (Rizzi & al. 2011, Neuwirth 2018). S - Bas (Nimis & Tretiach 1999), Si (Grillo 1998, Grillo & Caniglia 2004).
Description: Thallus crustose, endosubstratic to thinly episubstratic, farinose, whitish grey to pale grey. Apothecia lecanorine, immersed to adnate, 0.3-0.6 mm across, with a reddish brown to blackish, epruinose disc, and a thin, often finally excluded thalline margin. Thalline exciple thin, ecorticate, filled with algae at least in lower part; proper exciple thin; epithecium brownish; hymenium colourless, I+ blue turning reddish; paraphyses weakly conglutinated, the apical cells to 7 µm wide; hypothecium colourless. Asci 8-spored, clavate, with a K/I+ blue apical dome penetrated by a narrow, K/I- apical cushion surrounded by a narrow, deeply K/I+ blue zone, the wall K/I- but surrounded by an I+ red-brown, K/I+ blue outer layer, the ocular chamber relatively small, Biatora-type. Ascospores 3-septate, usually not constricted at septa, hyaline, narrowly ellipsoid, straight or (mostly) slightly curved, 12-15 x 4-5 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate species found on nutrient-rich or -enriched bark; closely related to L. fuscella.