Distribution: N - TAA (Thor & Nascimbene 2007, Nascimbene & al. 2008c, 2009, 2010, Nimis & al. 2015). S - Bas (Puntillo & Puntillo 2009, Puntillo & al. 2012), Cal (Puntillo 1994, 1996, Puntillo & Puntillo 2009).
Description: Thallus crustose, episubstratic, rather thin, verrucose or subareolate, smooth, greenish grey when fresh, assuming a brownish tinge in the herbarium. Apothecia sessile, short-cylindrical or lenticular, 0.3-0.7 mm across, 0.3-0.4 mm high, with a black, flattened mazaedium and a slightly pruinose margin. Proper exciple 40-140 µm thick laterally, expanded at the base up to 380 µm, of dark brown, sclerotized hyphae; hypothecium 110-140 µm thick, of periclinally arranged, sclerotized hyphae. Asci cylindrical, formed singly from hooked ascogenous hyphae, persisting until the spores are nearly ripe, with uniseriately arranged spores. Ascospores 1-septate, clearly constricted at septum, dark brown, ellipsoid, 12-17 x 7.5-10 µm, the wall at first smooth, later with cracks delimiting irregular polygonal areas. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: placodiolic acid and three unidentified substances.
Note: a mainly cool-temperate to southern boreal-montane lichen found on ancient boles of conifers in semi-natural montane forests, often on basal parts of trunks, mostly on old Abies, much more rarely on lignum; to be looked for further in the Alps. It is included in the Italian red list of epiphytic lichens as “Endangered” (Nascimbene & al. 2013c).
Growth form: Crustose
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)