Description: Thallus crustose, endosubstratic or composed of dull yellowish white, usually convex-granulose, 0.1-0.3 mm wide areoles. Apothecia micareoid, black or blue-black, sessile to substipitate, often tuberculate, 0.15-0.6(-0.9) mm across, with a convex to almost globose disc, without a proper margin. Proper exciple poorly developed and soon excluded, brownish in outer part; epithecium scarcely differentiated from the hymenium; hymenium 50-75 μm tall, colourless, or olivaceous to blue-green in upper and sometimes lower parts, the pigmented parts K-, N+ red, rarely with a few scattered, minute violaceous granules reacting K+ green; paraphyses numerous, 1.5-2 μm thick at mid-level, simple or sparingly branched in upper part, the apical cells often slightly swollen; hypothecium pale blue-green or olivaceous, K-, the central part often colourless or pale brown. Asci 8-spored, clavate to cylindrical-clavate, with an unstained wall and a K/I+ blue outer layer and apical dome, the latter with a non-amyloid, cylindrical axial mass. Ascospores (3-)4-7-septate, hyaline, fusiform to narrowly fusiform, straight or slightly curved, rounded at one end and acute at the other, 16-36(-38) x 4-6(-7) μm. Pycnidia more or less immersed, the wall green (K-) in upper parts. Conidia curved, 3-7-septate, 16-22 x c. 1 μm. Photobiont micareoid, the cells 4-7 μm wide. Spot tests: thallus K-, C+ yellow-orange, KC+ orange, P-; apothecial sections C-. Chemistry: unidentified xanthones.
Note: although sometimes sympatric with the typical variety, this taxon is restricted to very humid areas at lower altitudes. Surprisingly, the only Italian record is from a rather dry-continental region (see Nimis 1993: 435). This variety is included in the Italian red list of epiphytic lichens as “Data Deficient” (Nascimbene & al. 2013c).