Description: This soft, damp, calcareous rock specialist (old mortar especially) with a thin, grey-brown, granular thallus, has its large, almost flat-topped, spherical discs (perithecia) up to half-buried in the substratum (to 1.5mm diam.) with just its top end showing. The discs are double-strengthened by a thick wall of black tissue (involucrellum) which curves around it like a cannonball. Scattered in Ireland, but probably much overlooked.

Key Identification Features:

• The relatively large spherical discs, thick involucrellum and requirement for soft, calcareous rock, for example, old mortar, should serve to distinguish it
• Acrocordia conoidea can look similar but is pinkish with rounder discs and occurs on harder limestones such as those used for headstones in old churchyards.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Acrocordia salweyi at iNaturalist World Species Observations database.