Order: Teloschistales Family: Teloschistaceae
Species: Caloplaca arnoldii
Photos: On rock. Killarney NP, Co. Kerry, SW Ireland.
Identified by John Douglass
Thallus is crustose in the centre with minute lobes at the margins, the tips adpressed. Initially yellow-orange, becoming deep reddish-orange. Apothecia with orange-red discs, 0.2-0.5mm, well developed orange margins. K+ red-purple.
Widespread but scarce on well-lit siliceous rocks, usually coastal.
Caloplaca arnoldii. November 2010