Lecanactis dilleniana (Ach.) Körb.

    Thallus crustose, rather thin, more or less effuse, tomentose scurfy, areolate to verrucose, non-sorediate, whitish, very pale grey-pink, slightly glaucous in the most lit sections, more or less tinged mauve-pink or pink-orange in shaded sections, prothallus inconspicuous, brown-darkish purplish. Apothecia immersed at first then almost sessile when mature, 0.5-1.5 mm diam., variable in shape: rounded becoming angular or elongate, disc more or less exposed, blackish but appearing grey-pruinose, exciple persistent, blackish. Ascopores fusiform, straight or slightly curved, 3-5-septate, 21-30 x 4-5 µm. Photobiont: Trentepohlia. Thallus and pruine : C-, K-, KC-, Pd+ yellow-orange. In dry, shaded, siliceous rock crevices and under overhangs. N.B. Not to be confused with Lecanographa abscondita and Lecanographa grumulosa  which are Pd- and darker grey.*