Melanohalea exasperatula (Nyl.) O. Blanco & al.

    Thallus foliose, rosette-forming, 3-6 (10) cm diam., composed of lobes, 1-4 mm wide, apices indented, upper surface brown-greenish, brown-olivaceous, grey-green-brown when dry, not glossy but gelatinous when moist, covered with tangled terete or branched isidia, typically swollen towards the middle or the tip and then spatula-shaped, lower surface pale brownish with simple rhizines. Apothecia rare, 2-3 mm diam., disc concave, brown-red, exciple isidiate. Ascospores simple, ellipsoid, 8-10 x 4-8 µm, Photobiont: trebouxioid. Chemical spot tests negative. Rather rare, on trunks and main branches or ornamental deciduous trees, very seldom on rocks.*