Thallus crustose, to 6 cm diam, 0.13–0.25 mm thick, sometimes rimose to areolate, the areoles occasionally ascendant at the edge and subsquamulose, upper surface smooth, matt greyish brown, with an upper epinecral layer usually present to 20 µm thick, of loose air-filled tissue; cortex inconspicuous, cells at the outer rim globose, to 5 µm diam, brown-pigmented, N-. Prothallus brownish grey, inconspicuous or absent.
Anamorph: conidiomata pycnidia, always abundant, ca 60 µm diam., immersed, hyaline at the base, dark brown above. Conidia 2.5–3 x ca 1 µm, ellipsoidal.
Teleomorph: ascomata apothecial, abundant, to 0.3(–0.35) mm diam, broadly appressed to sessile, flat, the disc brownish black; margin 30-50 µm thick, often evanescent, concolorous with the disc, algae in under part only, composed of paraplectenchyma with cells 3-3.5 µm diam, outer rim of margin, especially above, with dark brown-pigmented cells; hymenium 40–50 µm thick; epihymenium brown due to the pigmented apices of the paraphyses, N-. Interascal tissue of paraphyses, not or slightly conglutinated, 1.2–1.8 µm diam, widened at the apices to 5(–6) µm diam. Asci 25–35 x 8–10 µm, Catillaria-type, 8-spored. Ascospores 8.5–10.5 x 3–3.5 mm, 1-septate, ellipsoidal to broadly fusiform, with a gelatinous sheath to 1.5 µm thick, sometimes indistinct.