Description: Thallus crustose, homoiomerous, subgelatinous when wet, ecorticate, of granular, subumbilicate small warts, red-brown and white-spotted, to 0.2 mm thick. Thallus anatomy paraplectenchymatous, the hyphae forming a network around the photobiont cells. Apothecia formed in a tangle of generative hyphae. to 0.5 mm across, immersed to adnate, with a flat to convex, red-brown, shining disc, and a whitish, irregular margin containing green algae. Thalline exciple thick, paraplectenchymatous; proper exciple thin, 10-15 μm wide, of parallel hyphae; epithecium brownish; hymenium colourless, 125-150 μm high, I-, K/I-; paraphyses slender, sparingly branched, septate, gelatinized, c. 2 μm thick, not swollen at tips; hypothecium brownish. Asci 8-spored, cylindrical, bitunicate, rostrate, with a 1+ blue outer coat the apical part separated from the expanded amyloid rostrum by a non-amyloid zone. Ascospores 1-celled, hyaline, oblong to slightly curved, 9-13 x 4-7 μm. Pycnidia rare, immersed in warts. Conidia bacilliform, 4-5 x c. 1 μm. Photobiont cyanobacterial, chroococcoid (Gloeocapsa), surrounded by a reddish (in outer parts) to colourless (in inner parts) gelatinous sheath, with additional trebouxioid green algae in delimited areas, especially in the thalline margin of apothecia. Spot tests: all negative. Chemistry: without lichen substances.
Note: a species with an areolate thallus, the granulose areoles being dark brown and spotted pale brown due to the presence of two photobionts, and with minute lecanorine apothecia recalling small garnets, found on periodically wet siliceous boulders and outcrops in sunny places, from the subalpine to the nival belt; widespread in the Holarctic region but altogether rare. The sample from South Tyrol was collected by Arnold near Predazzo (Margola) on syenitic rocks.