Mycelium not staining blue in iodine.
Anamorph: not definitely known.
Teleomorph: ascomata apothecia, (100-) 150-250 (-350) µm diam., sessile to substipitate, black, epruinose or with a dark scarcely visible pruina. Hymenium brownish, K+ green in the upper part and K- in the lower part. Epithecium composed of a reddish brown to dark olivaceous crystalline layer, dissolving in K to produce a yellow pigment. Hypothecium dark reddish brown, K- or K+ yellowish. Excipular tissue composed of brown isodiametric or elongate, sometimes branched cells. Interascal tissue composed of paraphyses 1.5-2.5 µm diam., hyaline, branched , not thickened at the apex. Asci 8-spored. Ascospores (10.5-) 12-14.5 (-16.5) x (4.5-) 5.5-6.5 (-7) µm, ratio length:width (1.8-) 2-2.5 (-3.2), 1-septate with slightly unequal cells, distinctly constricted at the septum, at first olivaceous, then brown, with a verrucose surface.
Assessed by Woods & Coppins (2012) as of Least Concern, but listed as Nationally Scarce due to the small number of occurrence records.
Parasitic on thalli of Hypogymnia physodes, sometimes forming on black spots not caused by the parasite (Diederich 1990).
Scattered throughout the Scottish Highlands, with a single record from central Scotland and one from Cornwall. BLS map here.