• Lecanora horiza (Ach.) Linds.
Lecanora horiza
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This species is a Lecanora chlarotera lookalike which grows mainly on basic-barked trees such as ash and sycamore. Unlike L. chlarotera it has a distinctly cracked and warted thallus above a white prothallus and glossy orange or brown discs often aggregated into clusters. The red-brown epithecium has a top layer of fine granules (in L. chlarotera these are coarse) and a weakly yellow K reaction. In Ireland, the species occurs in Counties Cork and Fermanagh.

Key characteristics

  • Like L. chlarotera but with a white prothallus, discs crowded into groups, fine granules lying on the epithecium and weak, K+ yellow spot test.
  • On basic-barked trees.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Lecanora horiza (Ach.) Linds.. [In] LichenIreland. Accessed on 2018-08-16.