Lecidella carpathica Körb.
Lecidea advertens Nyl.
Thallus crustose, coarsely granulose to markedly verrucose, sometimes discontinuous, whitish, dull whitish, sometimes whitish-greenish, whitish-brownish. Apothecia to 0.5-1 mm diam., more or less immersed in the thallus, flat at first then more or less sessile and markedly convex when mature, disc black, exciple thin and wavy at first, excluded when apothecia become convex. Ascospores simple, ellipsoid, 10-16 x 6-8,5 µm, according to the literature, 10-15 x 6-8 µm according to our measurements. Photobiot: chlorococcoid. Thallus: C-, K+ yellow, KC+ yellow, Pd+/- yellow. Rather common, on more or less siliceous rocks, wall stones, etc., may be parasite of other saxicolous lichens at first.
See Lecidella stigmatea that grows on less acid rocks and at maturity with less convex apothecia, and less coarsely verrucose thallus.*