Description: Thallus crustose, episubstratic, areolate, the areoles angular, flat, pale yellow-orange, 0.5-0.9 mm wide, 145-170 µm thick, separated by distinct cracks in dry thalli, without a distinct prothallus. Cortex 7-8 µm thick, with a yellowish- greenish grey pigment; algal layer 40-80 µm thick; medulla white, 60-85 µm thick, hydrophobic and with air-filled spaces in water-mounted sections. Apothecia cryptolecanorine-aspicilioid, immersed in the areoles, rounded to elongate or irregular in outline, 0.3-0.5 mm wide, with a dark disc and a barely raised margin. Exciple 45-50 µm thick; epithecium with a dark yellowish-brown pigment partly soluble in N (Caesiocinerea-green), N+ emerald green, K+ pale yellow, c. 25 µm high; hymenium colourless, (123-)200-250 µm high, without oil droplets, I+ bluish; paraphyses not moniliform; hypothecium colourless. Asci (2-)4(-6)-spored, clavate, the thin outer coat K/I+ blue, the wall and apical dome K/I-. Ascospores rarely well-developed, 1-celled, hyaline, broadly ellipsoid to subglobose, 19-22 x 14-17 µm. Pycnidia black, immersed in the Thallus. Conidia bacilliform to filiform, straight to slightly curved, 10-11 x 0.3-0.4 µm. Photobiont chlorococcoid, the cells up to 9-11 µm in diam. Spot tests: cortex K- or very faintly K+ yellow (the pigment leaking in the solution), C-, KC-, P-; medulla K-. Chemistry: no lichen substances detected.
Note: a recently-described species growing on siliceous rocks in the splash-zone of permanent and temporarily dry, sun-exposed stretches of Mediterranean streams in the montane belt, hitherto known only from Sardinia.