Description: Thallus crustose, pale green to pale brown, thin, finely granular, covered with (15-)20-40(-50) μm thick, soredia-like goniocysts. Apothecia biatorine, (0.2-)0.3-0.6(-0.7) mm across, with a flat, white to pale orange-pink disc and a thin proper margin. Proper exciple colourless, of gelatinised cells; epithecium not clearly differentiated from the hymenium; hymenium colourless, 35-55 μm high; paraphyses 1.5-2 μm thick, simple or forked in upper part, the apical cells often swollen, up to 5 μm wide; hypothecium colourless. Asci 8-spored, cylindrical-clavate, approaching the Bacidia-type, but the ocular chamber wider, and the axial body never penetrating through the entire d-layer, surrounded by a narrow, darker amyloid layer. Ascospores 3-7-septate, hyaline, acicular, (20-)25-48 x 1-1.5(-2) μm, without a perispore. Pycnidia white, more or less immersed. Conidia filiform, curved, 20-40 x c. 1 μm. Photobiont chlorococcoid, the cells 5-10(-12) μm in diam. Spot tests: thallus and apothecia K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a Mediterranean-Atlantic to humid subtropical species found on bark, especially of Sambucus and Salix and - but only in very humid areas - on roofing tiles and plant debris.
Growth form: Crustose
Substrata: bark and rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)