Description: Thallus crustose thinly episubstratic, farinose, glaucous green. Apothecia stalked, pin-like, 0.7-1.6 mm high. Stalk brown to black in lower part, whitish to dull brownish in upper part, of periclinally arranged, medium brown hyphae. Capitulum spherical, with a poorly developed excipulum forming a basal collar not visible from above; lower side of excipulum brown, paler and apparently pruinose around the mazaedium, due to a hyphal web which tends to trap the brown ascospores. Mazaedium well-developed, brown; hypothecium brown, with a strongly convex upper surface. Asci short-cylindrical or irregular, formed in chains, dissolving early, with 1-seriate to irregularly arranged ascospores. Ascospores 1-celled, brown, globose, 3.5-4 µm wide, with a smooth to irregularly cracked wall. Photobiont chlorococcoid, with rectangular cells (Stichococcus). Spot tests: thallus K-, C-, KC-, P+ yellow to reddish. Chemistry: thallus with barbatic and obtusatic acids.
Note: a cool-temperate to boreal-montane, circumpolar lichen found in rain-protected hollows of conifer trunks inside forests, especially near the ground, both on bark and lignum, sometimes on acid-barked deciduous trees, e.g. Betula and Quercus. It is included in the Italian red list of epiphytic lichens under the “Least Concern” category (Nascimbene & al. 2013c).