Lecanora farinaria  

Thallus of contiguous areoles, grey-white, sometimes slightly yellow, green or brown, smooth. Soredia arising in small mounds which may coalesce and cover the whole thallus surface, farinose to granular, yellow or white.
Anamorph: no information available.
Teleomorph: ascomata apothecia, rare, 0.4-1 (-1.5) mm diam., dispersed or aggregated, at first immersed amongst the soredia
but finally erumpent. Thalline exciple at first well-developed, later becoming excluded, sorediate when young, the medulla with very large crystals not dissolving in K. Disc pale reddish brown to black, sometimes partly pallid, finally convex. Epithecium yellow- to green-brown, interspersed with granular crystals dissolving in K but not N. Hymenium 50-75 μm tall. Interascal tissue of paraphyses ca 1 μm diam., anastomosed below, sparsely branched above, the apices green-brown, not swollen. Ascospores (10-) 14-17 (-20) × 7-15 μm, broadly ellipsoidal to subglobose, very thick-walled.
Chemistry: thallus and soralia C–, K+ yellow, Pd+ weakly yellow, UV– (atranorin, roccellic acid).