Distribution: N - VG, Frl, Ven (Lazzarin 2000b), Piem, Emil (Fariselli & al. 2020), Lig. C - Tosc, Marc (Nimis & Tretiach 1999), Laz, Sar. S - Camp (Aprile & al. 2003b), Bas, Pugl, Cal (Puntillo 1996), Si.
Description: Thallus crustose, episubstratic, areolate, white to grey-white, sometimes delimited by a black prothallus. Upper cortex pseudoparenchymatous, with minute crystals not soluble in K; medulla white, I-. Apothecia lecideine, 0.2-0.3 mm across, at first immersed, then emergent, adnate, without a spurious thalline margin; disc black, sometimes white-pruinose, at first flat then convex; proper margin thin, finally excluded. Epithecium brown; hymenium colourless, not inspersed with oil droplets, K/I+ blue; paraphyses simple with enlarged, pigmented apical cells; hypothecium brown. Asci 8-spored, clavate to cylindrical-clavate, the apical dome K/I+ dark blue with a pale, conical-pointed apical cushion (axial mass), the wall I-, but the thin outer gel I+ blue, approaching the Bacidia-type. Ascospores 3-septate, brown, with rounded lumina, very thick-walled, not ornamented, often curved, 13-18 x 8-11 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mild-temperate lichen found on isolated trees with eutrophic or eutrophicated bark, usually at relatively low elevations. The relationship with D. alboatrum needs to be clarified.
The Trustees of the Natural History Museum, London – CC BY-SA 4.0 Source: http://data.nhm.ac.uk/dataset/56e711e6-c847-4f99-915a-6894bb5c5dea/resource/05ff2255-c38a-40c9-b657-4ccb55ab2feb?view_id=6ba121d1-da26-4ee1-81fa-7da11e68f68e&filters=subDepartment%3ALichens%7CgbifIssue%3ATAXON_MATCH_HIGHERRANK%7Cfamily%3Acaliciaceae