Ochrolechia subviridis (Hoeg) Erichsen

    Thallus crustose, rather thick, rough, coating the substratum, smooth to granular, dull whitish, grey-whitish, covered with heaps of coralloid isidia, terete, breakable and when broken producing granular soredia, isidia in isolated clusters at first, then covering gradually almost all the thallus surface with a thick matt, more or less cracked, pale grey-greenish, white-greenish when moist, pale greyish when dry, prothallus sometimes inconspicuous, zonate, white and pale brown to pink-brown. Apothecia very rare, sessile, 1-4 mm diam., disc rough, brown-pink, exciple thick, isidiate. Ascospores simple, broadly ellipsoid, 30-68 x 25-35 µm. Photobiont: Chlorococcoid. Isidia : C+ red, K-, KC+ red, Pd-. Rare, on trunks of tall deciduous trees and notably ornmental trees.*