Galapagos Species Database

Thallus thin, often partially embedded in the bark, continuous to rimose, pale creamy white, grayish or ochraceous, ± the same color as the substrate; surface smooth to ±verrucose, not pruinose; Apothecia immersed to prominent, ±lirellate; lirellae broad, short, oval, typically not branched or barely lobed; labia thick, broad, often with an additional thin, papery thallus layer, young lirellae as if “bursting open” from fissures; disc expanded, initially ±concave and ±immersed, but soon flattened, epruinose; exciple thin, weakly and irregularly carbonized, carbonization not increasing with age, typically surrounded by a thin, but distinct thallus layer; hymenium hyaline, inspers, I–; ascospores pale gray, brownish with age, I+ red or reddish brown, 8 per ascus, oblong to broadly fusiform, 24-40 x 11-12 µm , (sub)muriform, 8-13 vs. 1-2(3) celled. Chemistry: Norstictic & connorstictic acid, K+ orange (crystals; reaction often weak & slow).

A very distinctive species that cannot easily be confused, occasionally similar to P. lobata, which generally has much more distinctly circular lirellae. Phaeographis atromaculata is morphologically and chemically similar but has much larger ascospores and a darker apothecial disc.