Thallus forming cushions up to 3cm diam., composed of brown to dark brown, partly ascending squamules with a paler margin, becoming blackened at the apices and at spots along the edges that become raised and evolve into isidioid structures 0·1–0·2mm thick and 0·6mm tall; <italics>squamules</italics> finally becoming completely blackened. Cortex composed of a single layer of thin-walled cells. Photobiont Nostoc, in short chains enclosed in a reticulum of hyphae, individual cells 5–6 μm diam.
Apothecia fairly abundant but difficult to observe among the isidia, sessile, partly clustered, black, ≤2mm diam. with distinct proper exciple, ≤200 μm wide (Fig. 2D). Hymenium non-amyloid, 120–150 μm high of simple, septate hyphae, apically with dark pigment. Asci to 150 μm, slender, thin-walled, I+ blue, but without apical amyloid structures; ascospores hyaline, ellipsoid, 17–19(20) × 8–9(10) μm, often with oil drops and occasionally appearing septate (pseudoseptate). Conidiomata not observed.
Chemistry. No lichen substances detected (by TLC).