Description: This species of calcareous rocks has its whitish thallus immersed in the rock. The discs (perithecia) are in pits and have tiny, hairline cracks radiating from some of them like a child’s drawing of the sun. The spores often have dark contents which can be a good identification character. In Ireland, the species is local but not rare (Counties Clare and Sligo).

Key Identification Features:

• Thallus white with perithecia in pits and with small cracks radiating away from some of these
• Spores about 25µm long and spore sacs (asci) often with cloudy or darkened contents.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Bagliettoa calciseda at iNaturalist World Species Observations database.