Description: Local and rare, A. macrospora grows on sunny calcareous rocks where it forms thick, pale or white-brown patches of interlocking, shield-like scales (squamules) which become more grossly squamulose towards the edges of the thallus. Frosting (pruina) is absent. Discs are common, widely exposed, usually darker than the thallus. The spores are large 6-13 x 3-6&

371;m. In Ireland, the species has been recorded from Counties Cork and Kerry.

Key Identification Features:

• Thallus of pale brown, non-pruinose overlapping and interlocking scales
• Discs widely exposed and with large spores (hence macrospora); sunny calcareous rocks.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Acarospora macrospora at iNaturalist World Species Observations database.