Description: Thallus foliose, heteromerous, forming rosettes or irregular, up to 10 cm wide, loosely attached. Lobes to 1 cm wide, elongate, partly overlapping, with subrotund, entire or lobulate margins. Upper surface grey-brown to dark brown, smooth, sometimes slightly pubescent, esorediate; medulla white; lower surface corticated, pale brown to yellow-brown, darker in the centre, smooth in marginal parts, rugulose in central parts, glabrous to weakly pubescent Apothecia common, immersed on lower surface at tips of lobes, orbicular, to 1 cm across, cup-shaped, with a brown disc and a scabrid thalloid dorsal surface. Epithecium brownish; hymenium and hypothecium colourless. Asci 8-spored, fissitunicate, the thickened apex with a K/I+ blue ring, Peltigera-type. Ascospores 3-septate, pale brown, subfusiform, thick-walled, (15-)17-21(-23) x 4-6 µm. Pycnidia laminal, immersed, punctiform. Conidia rod-shaped, 4-5 x 1.5-2 µm. Photobiont cyanobacterial (Nostoc). Spot tests: upper cortex K-, C-, KC-, P-; medulla K+ pale yellow or K-, C-, KC-, P-. Chemistry: upper cortex with an unknown brown pigment; medulla with triterpenes.
Note: a holarctic Lobarion-species of bark, epiphytic bryophytes and mossy rocks in humid forests. It is included in the Italian red list of epiphytic lichens as “Near-threatened” (Nascimbene & al. 2013c).