• Lecanora agardhiana Ach.
Lecanora agardhiana
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(Map updated: 11 August 2009)

This very distinctive small crustose lichen has a pale grey-white or inconspicuous thallus studded with immersed, blue-grey frosted discs. It is extremely eye-catching and would only be confused with Lecanora crenulata which has larger sessile discs on rock without the blue-green epithecium (section the disc to view) of this species. Clauzadea immersa has immersed, frosted discs which are brown when wetted. L. agardhiana grows most prolifically on the horizontal surfaces of hard calcareous rocks in coastal situations. In Ireland, it has been recorded from Counties Dublin, Monaghan and Antrim.

Key characteristics

  • Immersed blue-grey frosted discs which in the sun can look like jewels on the surface of the rock
  • Calcareous rocks near the coast; cliff tops.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Lecanora agardhiana Ach.. [In] LichenIreland. Accessed on 2019-12-10.