Description: Thallus crustose, thinly episubstratic, continuous to rimose-areolate, grey, rarely dark grey or dirty white, the areoles 0.5-1 mm wide, sometimes constricted at base. Apothecia biatorine or lecideine, 0.2-0.7 mm across, sessile, not constricted at base, with a flat to convex disc of variable colour, from brownish yellow to orange-brown or finally entirely black (the yellow to orange pigment appearing as a pruina), and a persistent to finally excluded, black to olive, smooth proper margin. Proper exciple broad, prosoplectenchymatous, the outer part blackish green, K-, N+ purple-red; epithecium yellowish orange, K+ red; hymenium colourless, 65-90(-135) μm high; paraphyses sparingly branched in upper part, the terminal cells swollen, 1.5-4 μm wide; hypothecium yellowish to brownish, 50-125 μm high. Asci 8-spored, cylindrical-clavate, functionally unitunicate, apically thickened with a broad internal beak, the inner part of apex and external cap I+ blue, Teloschistes-type. Ascospores 2-celled, polarilocular, hyaline, ellipsoid, (10-)12-16.5 x (5.5-)6-7.5(-8) μm, the equatorial thickening (“septum”) 3-5(-7) μm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-; apothecia K- or K+ red, C-. Chemistry: Cinereorufa-green pigment in thallus and apothecial margin; apothecia with 7-chloroemodin, emodin, fallacinal, fragilin, parietin, parietinic acid, teloschistin and an unknown substance.
Note: a mainly arctic-alpine, probably circumpolar lichen of basic siliceous rocks in humid, wind-protected situations above and near treeline; certainly much more widespread in the Alps.