Description: This is a common crustose lichen of acid rocks above the seashore, closely resembling V. nigricans and V. macrostoma (both described elsewhere). It is never as dark as V. nigrescens and has a well-developed, pale to dark brown, slightly mottled thallus above a black prothallus (a foundation layer). The half-immersed black spherical discs (perithecia) sit stoutly on the surface. It occurs widely on suitable habitat throughout Ireland.

Key Identification Features:

• On acidic (silica-rich) rather than calcareous rocks. Other members of the genus on the shore occur mostly below the high-tide mark
• The habitat, brown-mottling of the thallus, and black, naked perithecia best distinguish it.

Original text submitted by Simon Davey

Distribution Map from NBN: Verrucaria fusconigrescens at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Verrucaria fusconigrescens at iNaturalist World Species Observations database.