Distribution: N - Frl, TAA (Nascimbene & al. 2007b), Lomb, Piem (TSB 33564b), Lig (Watson 2014). C - Tosc, Marc (Nimis & Tretiach 1999), Laz, Sar (Zedda 2002). S - Camp (Aprile & al. 2003b), Bas (Nimis & Tretiach 1999), Cal (Puntillo 1996).
Description: Thallus crustose, endosubstratic or thinly episubstratic, discontinuous or of discrete to contiguous, almost granular, 0.2-0.8 mm wide areoles, whitish, pale grey or pale brown-grey, sometimes with a thin, endosubstratic, pale grey hypothallus. Apothecia lecideine, 0.2-0.8 mm across, green-blue, grey-bIue, blue-black, or palc dirty brown-yellow in shade-forms, often mottled, with an initially flat, finally often convex, epruinose disc, and a concolorous to paler (especially when wet), often finally excluded proper margin. Proper exciple 50-60 μm wide laterally, grey-green in outer part, without or with a single cell layer of enlarged, c. 4 μm wide cells, colourless to pale blue-green within, the pigmented parts K+ purplish, N+ orange-red; epithecium scarcely differentiated from the hymenium, pale green to blue-green, the pigmented parts K- and N+ purple; hymenium 40-65 μm high, colourless to pale brown in lower part, merging with the epithecium in upper part; paraphyses 1-1.5 μm thick at mid-level, the apical cells usually cIavatc, but sometimes weakly or not swollen, up to 5 μm wide; hypothecium colourless to very pale blue-green to straw-coloured. Asci 8-spored, clavate, surrounded by a gelatinous I+ blue coat, with a well-developed I+ blue tholus, a I+ darker blue tube and a well-developed ocular chamber, Bacidia-type. Ascospores (3-)7-9-septate, hyaline, needle-like, straight to sigmoid, 30-55(-70) x 2-3.5 μm, tapering towards one end. Photobiont chlorococcoid, the cells 5-12 μm in diam. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: thallus without lichen substances; apothecia with the Bagliettoa-green and Laurocerasi-brown pigments.
Note: a mild-temperate lichen, most frequent on Sambucus, or near the base of trees with nutrient-rich bark, with optimum in the submediterranean belt.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)