Distribution: N - Frl (TSB 15106), Ven (Nascimbene & Marini 2010), TAA (Nascimbene & al. 2006, 2007b).
Description: Thallus subleprose, consisting in a thin to rather thick, continuous or cracked crust of farinose, to 0.1 mm thick, pale yellowish white to yellowish grey blastidia. Apothecia very rare, lecideine, 0.5 mm across, first immersed in thallus, with a convex, black disc and a thin, finally excluded proper margin. Proper exciple dark blue-green throughout; epithecium dark blue-green, granular; hymenium colourless, 70-110 μm high, containing crystals; paraphyses easily made free in K, mostly simple, c. 1 μm thick at base, the apical cells slightly swollen; hypothecium golden brown. Asci 8-spored, clavate, with an intensely I+ blue tholus penetrated by a weakly amyloid, broadly cylindrical axial mass, and a poorly developed ocular chamber, Lecidella-type. Ascospores 1-celled, hyaline, ellipsoid to ovoid, 8-13(-17) x 4-7(-9) μm. Photobiont chlorococcoid. Spot tests: thallus (blastidia) K+ yellow, C+ orange, KC+ orange, P-. Chemistry: 2,7-dichlor-6-O-methylnorlichenxanthone.
Note: a mainly temperate lichen found on base-rich bark of deciduous trees (e.g. Fraxinus, or on nutrient-enriched lignum. For the chemistry see Knoph & Leuckert (1997). It is included in the Italian red list of epiphytic lichens as “Data Deficient” (Nascimbene & al. 2013c).