Description: This lichen is roughly intermediate in size between D. leptophylloides and D. luridum and like them grows on inundated siliceous rocks by rivers and loughs. Along rivers it appears to occupy a zone midway between the submerged and the amphibious so should be regarded as a strict aquatic species. Typically, the pale to dark brown, non-frosted thalli vary between 2-3cm diameter, attached by a single holdfast. The lower surface is darker (almost black) than in related species. It can tolerate silting. Widely distributed in Ireland.

Key Identification Features:

• Thallus, pale to dark brown above, blackened below
• Intermediate in size; a 1 aquatic lichen.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Dermatocarpon meiophyllizum at iNaturalist World Species Observations database.