Description: Thallus not lichenized, the hyphae immersed in the thallus of Candelariella vitellina and related species. Apothecia lecideine, glossy black, adnate, rounded or irregular in outline by mutual compression, 0.2-0.6 mm across, with a slightly concave to convex, epruinose disc, and a usually persistent, slightly raised, concolorous proper margin. Proper exciple black in the marginal part, dark brown within, N+ purple; epithecium bright blue-green to blue-black, c. 10 μm high, K+ bright emerald blue, N+ purple-red: hymenium pale blue-green in upper part, otherwise colourless, c. 40 µm high; paraphyses simple, conglutinated, 1-2 μm thick at mid-level, the apical cell to 2.5 µm wide; hypothecium colourless in upper part, pale to dark-brown in lower part, continuous with exciple, c. 65 μm high. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid to ovoid with rounded ends, 7-12 x 4-7 µm. Photobiont absent. Spot tests: all negative Chemistry: without lichen substances.
Note: a holarctic, temperate to arctic lichenicolous fungus growing on Candelariella vitellina, especially common in upland areas, but also found in the most humid parts of the Mediterranean belt.