Description: This is a species of intertidal rocks and stones, especially along sheltered shores and estuaries. Generally, the thin brown to blackish thallus lacks the cracked surface of similar species but has instead a fine stippling of small dark dots and ridges. The small (to 0.2mm diam.) spherical discs (perithecia) form shiny conical projections which sit almost on the surface like black beads. Throughout Ireland in suitable habitats.

Key Identification Features:

• Largely an intertidal zone lichen of rocks and stones; thallus brown with microscopic dots and ridges
• The black discs are evenly distributed and sit like beads on the surface.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Verrucaria ditmarsica at iNaturalist World Species Observations database.