Lecanora polytropa  

Thallus immersed and inconspicuous, or of dispersed granules or areoles, sometimes forming a continuous areolate crust, areoles when present ± rounded, 0.1-0.3 mm, surface flat and with even margins, usually yellow-green, occasionally becoming grey-green or brown, surface smooth. Soredia, isidia and cephalodia absent. Prothallus black when evident. Photobiont Trebouxia.
Anamorph: conidiomata pycnidia, immersed, walls hyaline but brown around the ostiole. Conidia (12-) 18-22 (-25) × ca 1 μm, needle-like to curved.
Teleomorph: ascomata apothecia, 0.3-1 (-1.5) mm diam., dispersed, sessile, constricted below, tending to arise singly on areoles which are then obscured. Thalline exciple initially well-developed and entire but becoming crenulate and excluded. Discs pale yellow to pale yellow-green, occasionally green brown or pale brown, finally convex, glaucous. Epithecium hyaline to yellow- or red-brown, interspersed with granular crystals dissolving in K. Hymenium 45-60 μm tall. Interascal tissue of paraphyses 1.5-2 (-2.5) μm diam., sparsely branched, the  apices slightly thickened. Asci 32-50 × 12-17 μm, cylindric-clavate, the apex strongly thickened with a K/I+ blue apical dome and a broad K/I– apical cushion, outermost gelatinous coat K/I+ blue, 8-spored. Ascospores (9-) 10-14 (-15) × (4.5-) 5-6.5 (-7) μm, ellipsoidal to ovoid-ellipsoidal, aseptate, hyaline, quite thick-walled, smooth, without an epispore, gelatinous sheath or appendages. 
Chemistry: thallus C–, K+ indistinctly yellow, KC+ yellow, Pd–, UV– (usnic acid, rangiformic acid, zeorin, ± eulecanoral acid).