Description: This rare Staurothele grows deeply immersed in pits in limestone rock. The thallus is vague so the discs (perithecia) need to be dug out with a razor blade and viewed under a high-powered microscope. The algal cells within the unprotected discs are globose-cuboid while the colourless spores are grouped together in pairs. The species should be looked for along the edges of limestone streams and loughs. In Ireland it occurs in the Burren, County Clare and in County Laois. In the Burren is grows by the side of a lough.

Key Identification Features:

• Perithecia in pits in limestone alongside streams or loughs
• Algal cells, globose-cuboid; spores colourless, two/ascus

Original text submitted by Vince J. Giavarini

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

iNaturalist: Staurothele guestphalica at iNaturalist World Species Observations database.