in Clauzade & Cl. Roux, Bull. Soc. Bot. Centre-Ouest, n. sér. 15: 130, 1984. Basionym: Aspicilia cinereorufescens f. subcandida Arnold - Verh. zool.-bot. Ges. Wien, 47: 223, 1897.
Synonyms: Lecanora subcandida (Arnold) Lettau
Distribution: N - Ven, TAA, Piem (TSB 33985), Lig (TSB 33667b).
Description: Thallus crustose, episubstratic, rimose-areolate, chalky white to whitish grey, usually not delimited by a distinct prothallus. Cortex filled by crystals visible under polarized light, masking the cortical cells; medulla white, I+ blue; algal layer extending below the hypothecium. Apothecia cryptolecanorine-aspicilioid, immersed in the areoles, 0.3-1.5 mm across, with a flat to slightly convex, brown to black-brown disc (reddish brown when wet), a darker proper margin, and a thin, often rapidly excluded thalline margin. Proper exciple sometimes greenish in outer part, always colourless within; epithecium pale 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, brown cap; hypothecium colourless, I+ pale blue. Asci 8-spored, clavate, approaching the Porpidia-type, with a less distinct tube structure. Ascospores 1-celled, hyaline, ellipsoid, 11-23 x 6-14 µm, the inner wall I+ blue or rarely I-, 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: a probably overlooked and certainly more widespread, characteristic lichen of base-rich, weakly calciferous siliceous rocks in the mountains, known from southern Europe (Alps, Pyrenees); perhaps just a calcicolous morph of B. cinereorufescens.