During lichenicolous fungal studies in India, lichen genus Ochrolechia was found infected with a black lirellate fungus. Critical microscopical examination of the fungus revealed that it is a new species of Labrocarpon, which differs from L. canariense in having narrow exciple (15.0–20.0 µm vs 20.0–50.0 µm thick), 4-spored asci, 1-septate to submuriform, constricted ascospores with larger l/w value [(2.5–)2.9–3.4–3.9(–4.5) vs (1.9–)2.1–2.5(–2.8)], habitat preference (corticolous vs saxicolous) and host selection (Ochrolechia vs Pertusaria). The new species Labrocarpon submuriforme is described in detail. Keywords: Himalaya; Melaspilea; Pertusaria; submuriform.