Colonies scattered or loosely aggregated on the surface of the lichen thallus, caespitose, dark brown to black, without any discoloration of the lichen thallus, but associated with black deposits between the host thallus areoles. Mycelium immersed; hyphae flexuous, branched, 2–7 (–9) μm diam., septate, cells rather short, 5–10 μm long, constricted at the septa, subhyaline to brown, sometimes blueish, smooth, walls thickened, up to 1 μm. Stromata lacking, but with solitary swollen hyphal cells, rarely aggregated below conidiophores, ovoid, doliiform or subglobose, 4–7 μm diam. Anamorph: conidiomata absent. Conidiophores somewhat differentiated from vegetative hyphae, 7–50 (–60) × 5–7 (–8) μm (with adhering conidia), not synnematous, solitary or in small caespitose tufts, terminal or lateral, usually erect, subcylindrical or doliiform, straight to slightly flexuous, often branched at the base; (0–) 1–8 (–9)-septate, constricted at the septa, brown to dark brown, paler towards the apex, frequently proliferating with obvious sheath-like wall remnants visible as an irregular fringe. Conidiogenous cells not differentiated from the conidiophore, subcylindrical or doliiform, 4–9 μm long, little differentiated, fertile loci truncate, unthickened, (2–) 3–5 (–6) μm diam. Conidia catenate, in unbranched chains, easily disintegrating, straight, rarely slightly curved, broadly ellipsoidal, doliiform or subcylindrical, (0–) 1–3-septate, aseptate conidia 5–13 (–15.5) × 4–6 μm, 1-septate conidia 7–17 × 4.5–7.5 μm, 2-septate conidia 10.5–19 × 5–8 μm, 3-septate conidia 13–20.5 × 5.5–7 μm, mostly constricted at the septa, brown to dark brown, paler near the apex, outer wall irregularly verrucose to rimulose, later scaly, wall thickened, 0.25–1 μm, the apex rounded in primary conidia, truncate in secondary ones, base truncate, scar truncate, sometimes slightly convex, unthickened, not darkened, (3–) 4–6 (–7) μm diam. Teleomorph: not known.
The material illustrated is identified only provisionally as this species; further research is needed.