Lecanora poliophaea (Wahlenb.) Ach.

    Thallus crustose, more or less round-shaped, areolate, 5-10 cm across, markedly rimose, papillate, warted, more or less covered with irregular papillae, sometimes with bluish or greyish-brown isidia, grey-brown tinged greenish, brown-greyish, dull grey-yellowish, warts sometimes grey, brown-greyish, grey-blue, prothallus conspicuous, fimbriate, slightly fan-shaped, with patches of light grey and dark grey-blue contrasting with the darker thallus. Apothecia often clustered, to 1 mm diam., innate at first soon sessile, disc flat, brown-red, brown-orange turning chesnut-brown to dark brown, exciple persistent, crenulate to nodulose, concolourous to the thallus. Ascospores simple, colourless, ellipsoid, 9-13 x 5-7 µm. Photobiont: Trebouxia. K-, KC-, C-, Pd-, UV+ yellow. Rare, strong maritime trends, on siliceous rocks more or less enriched, often in humid crevices, below the Lecanora praepostera level and above the black area with Hydropunctaria maura. See Lecania aipospila and Lecania fructigena that may grow nearby but which have 1-septate spores and a thallus much darker with angular warts.