Thallus crustose, greyish green to pale brownish green, at first granular to warted, then areolate to continuous; with a finely granular to warted surface; K± yellowish, KC–, C–, P–. Anamorph: conidiomata usually present, pycnidia, 50–100(–150) µm diam., unilocular, immersed in the thallus except for a dark brown to blackish ostiole. Conidiomatal wall composed of colourless tightly packed hyphal tissue. Conidiophores developing in a palisade from the entire inner surface, 4–6 x 1–2 µm, ± cylindrical but irregular in form. Conidiogenous cells 4–8 x 1–2 µm, terminal, cylindrical to flask-shaped, proliferating percurrently and sometimes annellidic. Conidia of two types: (1) 15–20 x ca 1 µm, filiform, curved to sigmoid, aseptate; and (2) 5–8 x 2–2.5 µm, bacilliform to ovoid, aseptate. Teleomorph: ascomata apothecia, (150–)200–750 µm diam., sessile, pale reddish brown to dark brown or black; margin darker than the disc, at first thick, later becoming excluded; disc flat or slightly convex, later becoming convex. Proper exciple 40–80 µm thick, composed of interwoven, radiating, branched and anastomosed hyphae with relatively thick gelatinous walls and cell lumina slightly constricted at the septa, the lateral part dominated by a greyish to blackish green pigment (reacting K+ green; N+ violet), gradually merging into the medulla, which is dominated by a reddish brown pigment (reacting K+ purplish red, N– and C+ intensifying red colour and finally bleaching). Hymenium 45–60 µm tall, colourless below, without a distinct epithecium but the upper part with varying amounts of green pigment as in the excipulum. Hypothecium pale greenish to reddish brown, ca 10 µm thick. Interascal tissue of simple or rarely branched paraphyses, straight, not or slightly anastomosed, the upper cells globose, to 2–3(–4) µm diam., with a thin gelatinous cap surrounding the upper cells that usually contain green pigment. Asci 35–45 x 7–12 µm, clavate, sometimes with an I+ darker blue area surrounding the conical I– axial mass, 8-spored. Ascospores 11–20 (–23) x 2·5–4·5 (–5) µm, narrowly ellipsoid to fusiform but slightly asymmetrical and tapering towards one end, colourless, straight, (1–)3-septate, without a perispore or ornamentation. Chemistry: no secondary substances detected by TLC.