Sagedia zonata  

Thallus dark grey with brownish tinge, unevenly areolate, smooth to verrucose, orbicular or effuse, sometimes forming concentric rings, very variable in form. Prothallus black. Areoles to 2.5 mm wide, sometimes surrounded by zones where the white, necrotic prothallus shines through, with a cortex 25-35 µm thick and cells 3-5 µm diam. Isidia and soredia absent.
Anamorph: conidiomata pycnidial, with straight or rarely curved conidia (7-) 7.5-10 (-12.5) µm in length.
Teleomorph: ascomata apothecia, to 1.2 mm diam., often numerous and strongly crowded, level with the thallus or somewhat raised, with a well-defined rim that is concolorous with the disc. Exciple to 50 µm thick, J+ pale to dark blue. Hymenium 85-95 µm thick, gelatinous, with paraphyses that are somewhat swollen (submoniliform) at the apex with the upper two or three cells rounded. Epihymenium dark green (caesiocinerea-green or aspicilia-green) , N+ emerald green, K+ brownish. Ascospores (14.5-) 17-20.5 (-22.5) x (7-) 8.5-11.5 (-13.5) µm in size, hyaline, aseptate.