Description: Thallus inapparent, not lichenized, the hyphae developing in the apothecia and the thallus of Rhizoplaca melanophthalma. Apothecia arthonioid, dispersed to aggregated, superficial, distinctly convex, black, rounded to slightly elongate, up to c. 2 mm across, without a proper margin. Epithecium brown-black; hymenium colourless, up to 40 μm high, the hymenial gel K/I+ blue; paraphysoids 2-2.5 μm thick, branched in upper part, the terminal cells up to 4 μm wide, with a black cap; hypothecium brownish. Asci 8-spored, broadly pyriform, approaching the Arthonia-type, c. 30 x 15 μm. Ascospores 1-septate with slightly unequal cells, hyaline, ellipsoid with rounded ends, 1l-13 x 4.5-5.5 μm. Photobiont absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: a lichenicolous fungus described from Greenland and also known from Switzerland, developing in the apothecia and the thallus of Rhizoplaca melanophthalma. To be looked for in the Italian Alps.
