Physcia mediterranea Nimis

    Thallus foliose, more or less placodioid, 3-8 cmm diam., tightly appressed to the substratum, lobate, lobes 0.5-1 mm wide, slightly palmate, indented, lobes more or less overlapping, convex or bulging, upper surface minutely maculate, slightly pruinose, pale grey, dull whitish, lower surface brownish, rhizine simple. Apothecia usually numerous, clustered towards the center, 1-3 mm diam., disc flat, brown-blackish, without pruine,  thalline exciple thick, concolourous to the thallus. Ascospores ellipsoid, pale brown, 1-septate, 14-19 x 7-10 µm according to literature. Photobiont: trebouxioid. Cortex: C-, K+ yellow, Pd-; medulla: K+/- yellow, C-, Pd-. Rare, Mediterranean, heliophile, halophile, on siliceous rocks near the seashore, notably in Corsica and Sardinia.

N.B. Very similar (and considered as synonymous by some authors) to Physcia albinea that differs only by its habitat afar from the sea.