Bacidia bagliettoana  (A. Massal. & De Not.) Jatta

    Thallus crustose, granular to irregularly warted, whitish, pale greyish when dry, grey-greenish when moist. Apothecia numerous, sessile, sometimes clustered and coalescent, 0.5-1.2 mm diam., disc flat at first, then convex but not globose when mature, smooth, always bright black irrespective of the state of dryness or humidity, exciple concolourous, thin, excluded when mature. Ascospores acicular, 3-7-septate, 25-30 x 2-2.5 µm Photobiont: Chlorococcoid. Chemical spot tests negative. On mosses covering calcareous rocks or on old calcareous walls, often on the ground among mosses and plant debris in calcareous fields and dunes. This species is rather similar to Bilimbia sabuletorum that  shares the same habitat and may coexist but the latter has some distinctive traits: apothecia larger and scattered, globose and rough when mature and above all, red, brown-red when humid, and also ascospores much larger and 2-3-septate. There are other rather similar species thriving on ground among or on mosses but they are mainly mountainous or continental.*