Distribution: N - TAA (Nascimbene & al. 2021), Lomb, Piem (Isocrono & al. 2004), VA (Piervittori & Isocrono 1999). C - Abr (Gheza & al. 2021)
Description: Thallus crustose, episubstratic, thick and warted-rimose, with a farinose, pale grey to pale brown surface. Apothecia lecanorine, sessile, 0.7-1.5(-2) mm across, with a black to brown-black, flat disc, and a thick, wavy or radially split thalline margin. Thalline exciple corticate, with many algae in the medulla, the cortical cells brown-capped; proper exciple thin, brown in outer part, paler within; epithecium yellowish brown to dark brown, with a sparse yellowish brown epipsamma; hymenium colourless, 75-90 µm high; paraphyses mostly simple, the apical cells clearly swollen, with a dark cap; hypothecium colourless. Asci 8-spored, clavate to subcylindrical, with a K/I+ blue outer coat and a K/I+ uniformly blue apical dome, Catillaria-type. Ascospores 1-septate, hyaline, ellipsoid, (12.5-)15-20(-22) x 5-9 µm including the gelatinous perispore. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: on thin layers of soil, on mosses and plant debris over calcareous substrata, with optimum near treeline; perhaps more widespread in the Alps, but certainly not common.
Growth form: Crustose
Substrata: soil, terricolous mosses, and plant debris