Lichens : Lecanorales : LecanoraceaeLichens

Myriolecis agardhiana (Ach.) ?liwa, Zhao Xin & Lumbsch

Description: 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 Identification Features:

  • 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

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

iNaturalist: Myriolecis agardhiana at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Myriolecis agardhiana. (Ach.) ?liwa, Zhao Xin & Lumbsch. [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=18562. Accessed on 2026-11-12.