Distribution: C - Marc (Brackel 2015, 2016), Abr (Brackel 2015, 2016), Sar (Brackel & Berger 2019).
Description: Thallus inapparent, not lichenized, forming discoloured patches on the thalli of Cladonia rangiformis. Apothecia arthonioid, black, epruinose, usually scattered, convex and cushion-like, immarginate, irregularly rounded, 0.1-0.2 mm wide, 75-85 μm tall, slightly constricted at base. Proper exciple very poorly developed; epithecium brown to orange-brown, 5-10 μm high, K-, I+ rust-red, K/I+ blue; hymenium colourless to brownish, 25-45 μm high, I+ red, K/I+ blue; paraphysoids 2-4(-5) μm thick, flexuous, branched, the apical cells up to 6(-8) μm wide; hypothecium brown. Asci (4-)8-spored, broadly clavate, semi-fissitunicate, with a large apical dome and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, with a cell wider and sometimes shorter than the other, not or only slightly constricted at septum, hyaline, soleiform, 8-10(-12) x 3-4.5 μm, smooth-walled. Photobiont absent. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a recently-described lichenicolous fungus known from three localities in Italy and from two others localities in Spain (Aragón), growing on the podetia of Cladonia rangiformis, where it causes a bleaching of the host thallus.
Growth form: Lichenicolous fungus
Substrata: soil, terricolous mosses, and plant debris