Distribution: N - TAA, Lomb, Piem (Isocrono & al. 2004, Isocrono & Piervittori 2008), VA (Piervittori & Isocrono 1999).
Description: Thallus crustose, episubstratic, grey to brownish grey, more or less grey-pruinose, thick, granulose to subsquamulose, Areoles/squamules 0.2-0.5(-1) mm broad, sometimes larger, contiguous, often forming an up to 4 cm wide, subrosulate crust, the surface finely rugose. Apothecia lecanorine, sessile, 0.5-2(-3.5) mm across, with a dark brown to blackish brown, mostly flat, epruinose disc, and a thick, crenulate, usually paler thalline margin. Thalline margin 0.06-0.2 mm wide, with numerous granules; proper exciple poorly developed laterally; epithecium brown; hymenium colourless, 85-100 µm high, I+ blue; paraphyses simple, conglutinate, 2.5-2 µm thick in middle part, the apical cells swollen and to 5 µm wide; lower part of hypothecium made up by strongly interwoven hyphae which separate it from the excipulum which extends below the hypothecium. Asci 8-spored, broadly clavate, with a I+ blue tholus, a broad ocular chamber, and a broadly cylindrical axial mass, Lecanora-type. Ascospores 1-celled (rarely 1-septate), hyaline, ellipsoid-cylindrical, thin-walled, 17-26 x 4-7 µm. Pycnidia dark, ovoid, immersed. Conidia bacilliform, 12-17 µm long. Photobiont chlorococcoid. Spot tests: thallus K+ yellow turning red, C-, KC-, P- or P+ pale yellow. Chemistry: norstictic and connorstictic acids.
Note: a mainly arctic-alpine species found on mosses (Andreaea, Grimmia) near or above treeline, often associated with cyanobacteria (Stigonema); almost certainly restricted to the Alps in Italy.
Growth form: Crustose
Substrata: soil, terricolous mosses, and plant debris
P.L. Nimis CC BY-SA 4.0 , Brazil. São Paulo. Praia de Peruibe near Itanhaém, in a dense mangrove forest on Laguncularia racemosa, 2 m, 24°10' S, 46°50' W. Leg. K. Kalb 24.02.1978 (Nr. 37602), det. K. Kalb. Dupl. ex Herbario Klaus Kalb.
P.L. Nimis; Owner: Department of Life Sciences, University of Trieste