Distribution: N - Ven, TAA, Lomb, Piem (Isocrono & al. 2004), VA (Piervittori & Isocrono 1999, Isocrono & al. 2008), Emil. C - Sar. S - Si.
Description: Thallus crustose, episubstratic, rimose areolate, rust-red, sometimes delimited by a pale prothallus. Areoles 0.3-0.8 mm wide, angular, contiguous, mostly flat to slightly convex. Algal layer extending below the hypothecium. Apothecia cryptolecanorine-aspicilioid, immersed in the areoles, 0.2-1.4(-2) mm across, with a concave to slightly convex, black (when dry), or lead-grey (when wet) disc, and a very thin thalline margin. Proper exciple poorly developed, more or less colourless, I+ blue; epithecium reddish brown, N-; hymenium colourless I+ blue; paraphyses branched and anastomosing in upper part, c. 2 µm thick, the apical cells not or only slightly swollen, usually with a thin, dark brown cap; hypothecium colourless, pale I+ blue, Asci 8-spored, clavate, approaching the Porpidia-type, with a less distinct tube structure. Ascospores 1-celled, hyaline, ellipsoid or slightly fusiform, (5-)9-18 x 4-9 µm, the inner wall I+ blue, with a thin halonate epispore. Pycnidia dark, immersed. Conidia short-bacilliform. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: an arctic-alpine, circumpolar lichen of metal-rich siliceous rocks, with optimum in the Alpine belt; somehow more hygro- and less photophytic than B. alpina.