Description: Thallus crustose, very thinly episubstratic, olive-grey to dark green, subgelatinous when wet. Apothecia round to short-ellipsoid or weakly angular, 0.15-0.25 mm across, semi-immersed in the thallus, with a slightly concave, yellowish brown, epruinose disc and a smooth, pale wayx yellow proper margin. Proper exciple colourless, 25-30 µm thick laterally, 10-12 µm thick in lower part, paraplectenchymatous; epithecium indistinct, colourless; hymenium colourless, 45-55 µm high, I+ yellowish, K/I-; paraphyses slender, c. 0.5 µm thick, indistinctly septate, simple, the apical cells hardly swollen; hypothecium very thin, colourless. Asci 8-spored, long-cylindrical, thin-walled, the upper part with a distinct, K/I- apical dome penetrated by a long, narrow tube extending from the endoascus, with 2-seriately arranged spores. Ascospores 3-septate, hyaline, fusiform-elongate to almost thread-like, with pointed ends, straight or slightly curved, 25-32 x 1.8-2 μm, with very thin walls and septa. Photobiont chlorococcoid, the cells 6-10 µm across. Spot tests: thallus K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: on wood, more rarely on siliceous rocks in forests; described from the Pyrenees and known also from a single station in the Swiss Alps; rare, but probably also very much overlooked. To be looked for in Italy.