Description: This species forms dots on rock in shallow streams in the uplands (south-west Ireland). The grey-green to brown thallus is minutely bubble-wrap blistered with discs (perithecia) each of which, except for the apex, is wrapped in a thin involucrellum and a layer of thallus. Spores are one-septate and within the medium range (24–30 x 10–14µm).

Key Identification Features:

• Thallus grey-green to brown; perithecia surrounded by an involucrellum and layer of thallus
• Spores one-septate >20µm long; wet shallow rocks, moorland streams.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Thelidium pluvium at iNaturalist World Species Observations database.