Infection not gall-inducing, not causing severe destruction of the thallus but sometimes noticeable necrosis can be observed. Anamorph: conidiomata pycnidia, subglobose to pyriform. Nonpigmented parts of the pycnidial wall K/I+ blue. Conidia ellipsoidal. Teleomorph: ascomata arthonioid apothecia, to 250 µm in diam., arranged in groups of 10-50, matt black, dull, often with a slight brownish tinge, convex, immarginate, ± circular, distributed over the surface of the host thallus including apothecial margins and hymenia. Exciple absent. Epithecium dark brown (due to the pigmented paraphysoidal tips) with a bluish tinge (due to a slight pigmentation of the hymenial gel), K+ chestnut-brown. Hymenium 30-45 µm tall, pale greyish, with K/I+ blue hymenial gel. Hypothecium pale brownish with some brown agglomerations, K/I-, the hyphae directly underneath K/I+ blue. Interascal tissue composed of paraphyses 1-1.5 µm diam., branched and anastomosed, with only slightly thickened terminal cells, apically about 2.5 µm diam., with pigmented caps. Asci 26-35 (-37) x (11-) 12-15.5 (-16.5) µm, clavate, with a K/I+ blue ring structure in the innermost layer of the endoascus, dehiscence fissitunicate, 8-spored. Ascospores (9-) 10-12 (-13.5) x (3-) 4-5 (-6) µm, clavate, 1-septate, the upper cell somewhat broader, and mostly shorter, hyaline, smooth, with a thin hyaline epispore or gelatinous sheath.