Description: Thallus inapparent, not lichenized, the hyphae developing inside old parts of thalli of Peltigera- and Solorina-species, the infected parts appearing as dark-brown, partly immersed, c. 0.5 mm wide patches. Apothecia arthonioid, developing in the cortex of the host, more or less round, adnate, 0.3-1.5 mm across, with a black, convex disc, without a proper margin. Proper exciple poorly developed; epithecium brown, K+ olive; hymenium pale brown, 45-50 µm high, K+ olive-green, I+ red, K/I+ blue; paraphysoids branched and anastomosing, 1.5-2.5(-3) µm thick, the apical cells up to 3.5 µm wide; hypothecium dark red-brown, up to 250 µm high, K+ olive-green, I+ red, K/I+ blue. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large, non-amyloid apical dome, and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, the upper cell slightly broader and more rounded than the lower cell, hyaline, ellipsoid-elongate to sole-shaped, (11-)14-20 x (4-)5-7 µm. Photobiont absent. Spot tests: K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a lichenicolous fungus growing on the thalli of Peltigera- and Solorina-species; never reported from Italy but to be looked for, especially in the Alps.
Growth form: Lichenicolous fungus
Substrata: soil, terricolous mosses, and plant debris