Glaucomaria carpinea  

Thallus forming discrete patches, generally continuous and smooth, thin, pale grey to white, tending to become darker and somewhat cracked in the centre with age. Prothallus white.
Anamorph: conidiomata pycnidia. Conidia 15-16 × ca 1 μm, thread-like to curved.
Teleomorph: ascomata apothecia 0.5-1 (-1.5) mm diam., sessile, slightly constricted at the base, often crowded. Thalline exciple well-developed, persistent, entire, sometimes becoming ± excluded with age. Disc pale red-brown to cream or purple, flat to somewhat convex, densely white-grey pruinose. Epithecium granular, pale yellow-brown, the granules dissolving in K. Hymenium 45-65 μm tall. Interascal tissue of paraphyses 1-2 μm diam., sparsely branched and anastomosed, apices not or slightly swollen. Asci 55-70 × 14-18 μm, clavate, stalked. Ascospores (9-) 10-12.5 (-14) × (5-) 6-8 μm., subglobose to ellipsoidal, sometimes inaequilateral, hyaline, aseptate, thick-walled, without a perispore, gelatinous sheath or appendages.
Chemistry: thallus C–, K+ yellow, Pd± pale yellow, UV± orange; apothecial disc C+ yellow or orange, UV+ pale to bright orange (atranorin, chloratranorin, sordidone).