Ochrolechia balcanica Verseghy
Thallus crustose, 5-8 cm across, more or less uneven, markedly verrucose, very pale grey-ochre, dull whitish, whitish. Apothecia usually numerous, sometimes clustered, sessile, 2-5 mm diam., disc flat, smooth, not powdery, pale brown, brown-orange, thalline exciple thick, smooth, without pruine, concolourous to the thallus. Ascospores broadly ellipsoid, colourless, 45-63 x 20-32 µm. Photobiont: chlorococcoid. Thallus: C+ red, K+ yellow, CK+ carmine, Pd-; apothecia: C+ carmine. Rare, restricted to Corsica, Côte d'Azur (Var department), West coast of Italia and Sardinia, on bark of old trees (Fagus, Castaneus...) of humid Mediterranean woodlands of montane zone (supra-Mediterranean zone). See also Ochrolechia tartarea which is rather similar but C+ orange, K- and Ochrolechia pallescens, C+ yellow, KC+ yellow.