• Lecanora expallens Ach.
Lecanora expallens
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This common bark lichen forms yellow-green or lemony-yellow, powdery patches. The consistency of the powder (soredia) is as if sifted through a fine mesh, so is never granular or gritty. Discs are infrequent, very small and only slightly pinker than the thallus. A dab of fresh bleach applied with the tip of a toothpick will turn the thallus orange.

Key characteristics

  • Powdery soredia is very fine and never gritty
  • Fresh bleach turns the colour of the thallus orange.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Lecanora expallens Ach.. [In] LichenIreland. Accessed on 2018-07-17.