Lecanora carpinea (L.) Vainio

    _{Thallus crustose, smooth and more or less rimose and  cracked, pale greyish, dull whitish, pale white-greenish, prothallus absent or white. Apothecia usually numerous, sometimes clustered and potentially distorted or angular owing to compression, slightly urceolate at first then flat and sessile becoming slightly convex, 0.5-1.5 mm diam., pale pinkish, pale brown-orange, at first covered with a dense whitish pruine, exciple distinct, entire, persistent, concolourous to the thallus. Ascospores simple, broadly ellipsoid, 12-14 x 6-7.5 µm. Photobiont: Trebouxia. Thallus: C-, K+ yellow, Pd- or Pd+  pale yellow; apothecia (exciple mainly): C+ yellow to yellow-orange, Pd-. Common, slightly nitrophile, on smooth bark of deciduous trees. Not to be confused with Lecanora albella of which apothecia exciple and disc are Pd+ red-orange.*}