Distribution: S - Si (Grillo & Cristaudo 1995, Brackel 2016).
Description: Thallus inapparent, not lichenized, the hyphae developing inside the thalli of Pertusaria-species, especially P. leioplaca, sometimes forming necrotic patches on the host thallus. Apothecia lirelliform, black, epruinose, simple or furcate, straight ot slightly curved, 0.2-1 x 0.1-0.2 mm, with a slit-like disc and a finely rugose proper margin. Proper exciple dark brown, 25-60 μm thick laterally, up to 115 μm thick at base, extending below the hymenium; epithecium brownish, K-; hymenium colourless to pale brown, 55-65 μm high, I+ blue in upper and lower parts, I+ reddish in the middle part; paraphysoids branched and anastomosing, 1.5-2 μm thick; hypothecium brown. Asci 4-spored, clavate, fissitunicate, without a K/I+ blue ring-structure in tholus. Ascospores (5-)6-septate, with an enlarged median cell, hyaline but sometimes turning brown when overmature, cylindrical, straight or slightly curved, 21-28(-31) x 4.5-6(-7) μm, with a 0.7-1 μm thick gelatinous perispore. Pycnidia immersed, brown-black. Conidia 1-celled, hyaline, oblong-ellipsoid, often tapering towards one end, 3.3-4 x 0.8-1 μm. Photobiont absent. Spot tests: K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a lichenicolous fungus growing on the thalli of Pertusaria-species, especially P. leioplaca, probably much more widespread.