Lecanora saligna (Schrader) Zahlbr.

    Thallus crustose, indeterminate, thickness highly variable and sometimes very thin, granulose, grey-yellowish, sometimes tinged green owing to algae, notably on horizontal surfaces with stagnant water, prothallus absent. Apothecia usually numerous, sessile, O.2-0.8 mm diam., disc flat to slightly concave or convex, colour covering the whole brown range: brown-red; brown-chocolate, brown-chestnut, pale brown, etc., exciple entire to crenulate, greyish to dull cream, usually persistent except when very old. Ascospores simple, colourless, ellipsoid, 7-13 x 4-6 µm. Pycnidia frequent, brown-reddish. Photobiont: Trebouxia. Chemical spot tests negative. Common (but neglected and understated), notably near the seashore on worked timber (even after wood preservation treatment or paint) in well-lit areas: wood poles, fences, structures, etc. N.B. This species is rather similar to a Lecanora dispersa  which would grow on wood and with smaller apothecia. Not to be confused with Lecanora varia which is more yellow-greenish and Pd+ yellow.*