Distribution: N - Ven (Nascimbene & al. 2021), TAA.
Description: Thallus crustose-subplacodioid, episubstratic, rimose to verrucose-areolate, white to yellowish grey, usually pruinose, sorediate, often delimited by a white, more or less arachnoid prothallus, forming up to 2(-3) cm wide, sometimes confluent patches. Areoles flat to convex, thick, ecorticate, with flat to convex, whitish to bluish grey soralia bearing granulose soredia; marginal areoles distinctly elongate, giving the thallus a placodioid appearance. Apothecia very rare, lecanorine, constricted at base to almost stalked, 0.3-1.5 mm across, with a white- or bluish grey-pruinose disc reacting C+ yellow, and a thin thalline margin, without an inner parathecial ring. Epithecium dark grey, densely inspersed with 1-2 µm thick granules reacting C+ yellow; hymenium colourless; paraphyses 1-1.5 µm thick; hypothecium colourless. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 9-14 x 6-7.5 µm. Photobiont chlorococcoid. Spot tests: thallus K+ yellow, C+ yellow-orange, KC+ orange, P+ pale yellow; apothecial disc C+ yellow. Chemistry: atranorin (major), eugenitol (minor), roccellic acid (major), and sordidone (major).
Note: a rarely collected species known from the Alps, the central European mountains and Scandinavia, found beneath underhanging surfaces of hard siliceous rocks in upland areas; perhaps overlooked and more widespread in the Alps, being almost always sterile.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)