Distribution: N - Lomb, Piem (Reeb & al. 2007), VA (HAL-18600).
Description: Thallus crustose-placodioid, episubstratic, areolate, forming orbicular patches to 5 cm wide; areoles round to angular, convex, 0.4-2.5 mm wide, contiguous or dispersed, very variable in colour, from epruinose and yellowish brown to reddish brown, to heavily white-pruinose, the marginal ones most often elongate and radiating, c. 2 mm long and 1 mm wide. Cortex paraplectenchymatous, reddish brown in upper part, colourless in lower part; algal layer continuous; medulla white, prosoplectenchymatous. Apothecia aspicilioid to lecanorine, round to irregular in outline, 0.3-1.8 mm across, immersed in the areoles, usually one per areole, with a dark reddish brown, epruinose, rough to umbilicate disc, and a rather thick, persistent thalline margin; proper margin often visible as a ring between disc and thalline margin. Proper exciple c. 20 µm thick; epithecium reddish brown; hymenium colourless, 80-140 µm high; paraphyses 1.5-2 µm thick at mid-level, the apical cell to 4 µm wide; hypothecium colourless. Asci >200-spored, clavate, the apical dome K/I-, Ascospores 1-celled, hyaline, narrowly ellipsoid, 3-5 x 1.5-2.5 µm. Photobiont chlorococcoid. Spot tests: cortex K-, C+ pink, KC+ pink, P- (reactions often ephemeral, to be observed under the microscope on thallus sections). Chemistry: cortex with gyrophoric acid.
Note: on steeply inclined faces of base-rich, weakly calciferous siliceous rocks in upland areas. Probably more widespread in the Alps. Closely related to the A. peliscypha complex (Knudsen & al. 2010), this species is worthy of further study.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)