Lecania rabenhorstii (Hepp) Arnold

    Thallus crustose, in orbicular patches, thick, more or less regular, areolate, areoles angular or lobule-like, notably towards the margin, brown-greyish, brown-greenish when moist, grey-yellowish to grey-brownish when dry, often black in between and below areoles. Apothecia emerging from areoles, numerous, 0.4-0.7 mm diam., sessile, disc sometimes pruinose, flat to slightly convex, brown-orange, brown-reddish, brown-blackish, exciple more or less persitent, faint yellowish contrasting with the disc. Ascospores ellipsoid, 1-septate, 11-15 x 4-7 µm. Photobiont: chlorococcoid. Chemical spot tests negative. Rare, strong coastal trends, on more or less neutral or alkaline rocks. N.B. Highly variable, the coastal taxa seems to be different from inland taxa (to be confirmed).*