Phaeophyscia orbicularis  

Thallus to 3 cm diam., orbicular, or irregular and confluent with others, ± closely appressed. Lobes 0.2-1.2 mm wide, usually ± radiating, separate to ± overlapping, pale grey or greenish grey to grey- or dark brown, occasionally yellowish, sometimes weakly white-spotted in pale, wide-lobed morphs, without marginal cilia but with some pale or white-tipped rhizines often projecting beyond the lobe margins. Underside black with simple, black rhizines. Medulla white or yellow-orange in the uppermost part. Soralia mostly orbicular, ± convex and laminal, sometimes marginal, grey to blackish or whitish (especially if abraded), occasionally yellowish.
Anamorph: conidiomata pycnidia, frequent; immersed, with hyaline walls except for a brown zone around the ostiole. Conidia 2-4 x 1-1.5 µm, bacillar, hyaline, aseptate.
Teleomorph: ascomata apothecia, occasional, to 1.5(-2.5) mm diam.. Thalline exciple smooth or rarely lobulate. Epithecium brown, hymenium and hypothecium hyaline. Interascal tissue of paraphyses, slender, often forked above, the apices clavate, pale brown with a thin dark brown cap. Asci ± cylindric-clavate, 8-spored, Lecanora-type. Ascospores 17-26 × 7-11 μm, brown, 1-septate, uniformly thick-walled. without a gelatinous sheath or epispore.
Chemistry: medulla with yellow or orange areas, K+ purple (skyrin), or no lichen products detectable (K–).