• Pertusaria corallina (L.) Arnold
Pertusaria corallina
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(Map updated: 11 August 2009)

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 characteristics

  • 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

 Simms, M. J., (2016). Pertusaria corallina (L.) Arnold. [In] LichenIreland. Accessed on 2019-03-25.