Description: P. corallina is among those upland lichens which by their colour, size and general abundance will be one of the first to be learned by the beginner. The spreading crusts on siliceous rocks are uniformly white with a bare, chalky edge (prothallus). The centre of the thallus is tightly packed with white, rod-shaped isidia which turn yellow with a dab of K (potassium hydroxide). Discs are uncommon and resemble white powdery warts.

Key Identification Features:

• Forms abundant white, chalky-edged patches on siliceous rocks, especially in upland areas
• Crusts are crammed with white, rod-like isidia which react K+ yellow.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Lepra corallina at iNaturalist World Species Observations database.