Synonyms: Gyalidea lecideopsis var. eucarpa (Servít) Vězda; Lopadium cacuminum H.Magn.
Distribution: N - TAA.
Description: Thallus crustose, endosubstratic or thinly episubstratic, often inconspicuous and poorly evident, smooth or finely granulose, grey-white to yellowish grey. Apothecia 0.4-0,6 mm across, with a concave, black to dark brown disc, and a smooth or radially split, mostly black to brown proper margin (often turning pure white in dry sites). Proper exciple 50-60 µm wide laterally, dark olive-brown in outer part, colourless or paler within; epithecium dark brown to brown-black; hymenium colourless or pale yellowish brown, 100-130 µm high; paraphyses mostly simple, to 1 µm thick, not swollen at apex; hypothecium colourless or pale yellowish brown. Asci 1-6-spored, thin-walled, apically thickened, with a small ocular chamber. Ascospores muriform, hyaline, ovoid to broadly ellipsoid, often of different sizes in the same ascus, 30-60 x 12-15 µm, without a distinct perispore. Photobiont chlorococcoid, Cystococcus/Leptosira-like. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a taxon with reduced spore numbers per ascus and muriform ascospores which are longer than 30 µm, found on limestone and dolomite in moist places, mostly in upland areas; widespread in Europe and also known from Asia and Arctic North America, but much rarer than the typical variety.