Description: Thallus squamulose, grey to greenish brown, sometimes spottly pruinose in the distal parts of squamules. Squamules 1-3 mm wide, 0.14-0.33 mm thick, dispersed or more frequently contiguous to slightly imbricate, rather loosely attached, entire or divided, the lower surface with a blackish-brown rhizohyphal web. Upper cortex thin, paraplectenchymatous, of (4-)19(-10) μm wide cells, with an up to 15 thick epinecral layer; algal layer poorly delimited from upper cortex; medulla of loose hyphae with many spherical cells and distinct interhyphal spaces; lower cortex absent, the medulla gradually merging into a dark mat of rhizohyphae, the latter 3-4 μm thick, brown to black. Perithecia to 0.2 mm wide, pyriform, without involucrellum, the exciple hyaline or pale yellowish-brown, except near the dark ostiole; periphyses rather short (to 30 μm long), often with somewhat swollen apical cells. Asci 8-spored, unitunicate, clavate, thin-walled, not or only slightly thickened at apex, without ocular chamber, the wall I-. Ascospores 1-celled, biseriate, ellipsoid to subfusiform, 12-19 x 5-7.5 μm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate, probably holarctic lichen found on the base of old trees, especially on rough bark in parklands and open woodlands, occasionally on epiphytic bryophyes, very rarely on epilithic mosses, with optimum in the submediterranean belt. It is included in the Italian red list of epiphytic lichens as “Near-threatened” (Nascimbene & al. 2013c).