Punctelia jeckeri  

Thallus 3-5 (-10) cm diam., with lobes usually 1-3 mm wide, closely appressed and ± contorted centrally, the margins ± rounded, irregular and upcurved. Upper surface (when fresh) pale greenish-grey and slightly shiny in the centre, turning to pale brownish-grey near the margin, young thalli entirely brownish to brownish-grey. Thallus close to the outer margin always pruinose, dull, the pruina consisting of crystals 2-10 μm in diam. Pseudocyphellae small, sparse to dense, mostly punctiform, occasionally elongating slightly and becoming sigmoid. Soralia primarily marginal along secondary lobes, with farinose to granular soredia, ± concolorous with the thallus. Lower surface creamy white to pale brown. Rhizines dense, simple or ± clumped, often with slightly paler tips, not extending to the margin.
Anamorph: conidiomata pycnidia, rare, laminal, immersed, brown. Conidia 3-5 x ca 1 µm, hooked or short-filiform.
Teleomorph: ascomata not known.
Chemistry: cortex K+ yellow; medulla C+ red, K–, KC+ red, Pd–, UV– (atranorin, lecanoric acid).