Distribution: C - Marc (Nimis & Tretiach 1999), Abr (Nimis & Tretiach 1999, Gheza & al. 2021).
Description: Thallus crustose, endosubstratic and usually evident only as a faint discolouration of the rock, forming 1-2 cm wide, more or less orbicular, often confluent patches. Apothecia 0.2-0.3 mm across, completely immersed in shallow pits of the rock, with a dark orange, usually flat to slightly convex disc, and a thin, slightly paler proper margin, without thalline margin. Epithecium orange-brown, K+ red; hymenium colourless, 60-70 µm high; paraphyses simple or sparingly branched, the apical cells swollen, to 6 µm wide; hypothecium colourless. Asci 8-spored, clavate, Teloschistes-type. Ascospores 1-septate, polarilocular, hyaline, ellipsoid, 11-13.5 x 5-6 µm, the septum 3.5-4 µm thick. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-; apothecia K+ red. Chemistry: apothecia with unidentified anthraquinones.
Note: a non-lichenicolous taxon with an endolithic thallus indicated by usually whitish patches, and sunken orange apothecia with slightly concave discs and thin parathecial margin (overall aspect recalling somewhat Protoblastenia incrustans); doubtfully distinct from the typical variety, it could be just a form poor in anthraquinones.