Distribution: N - TAA (Nascimbene 2002). C - Abr (TSB 30609). S - Camp (Nimis & Tretiach 2004).
Description: Thallus squamulose-subfruticose, homoiomerous, slightly gelatinous when wet, forming small, pillow-like, lobulate and umbilicate squamules 0.5-1.2 cm in diam. Upper surface black, but (at least in part) densely covered in a bluish pruina; peripheral lobules adpressed, flat, branched, sometimes imbricate; central lobules erect, cylindrical, simple or sparingly branched. Apothecia 8-13 in each squamule, terminal on the central lobules, or laminar in the peripheral ones, first immersed and urceolate, but soon expanded and clearly lecanorine, 0.5-1 mm across, with a dark reddish brown, concave to flat, often pruinose disc, and a thick prominent, first smooth then rugose thalline margin. Proper exciple well-developed, 25-40 µm wide; epithecium yellowish, to 25 µm high; hymenium colourless, 100-150 µm high, the hymenial gel I+ blue; paraphyses moniliform, 3-4.5 µm thick, the terminal cell much swollen and to 7 µm thick; hypothecium colourless, 30-50-100 µm high in central part. Asci 8-spored, cylindrical-clavate, thin-walled, with an amyloid apical cap. Ascospores 1-celled, hyaline broadly ellipsoid to subfusiform, 12-15(-17) x 8-10(-11) µm. Pycnidia immersed, globose. Conidia hyaline, ellipsoid or bacilliform, 3-4 x c. 1.5 µm. Photobiont cyanobacterial, chroococcoid, of a few cells 7-12 µm diam. surrounded by a gelatinous sheath which is yellowish brown to purple near the thallus surface. Spot tests: all negative. Chemistry: no lichen substances.
Note: on sunny seepage tracks of calciferous rocks, not common, but perhaps more widespread below the montane belt.