Species: Hypogymnia physodesGrowth type foliose.
Photos: On Larch, Salix and Oak. Co. Cork, SW Ireland.
Variable. Shiny grey-blue or greenish orbicular thallus, wide or narrow radiating lobes. Lobe tips often with black pycnidia, farinose soredia extend round margins. Rarely fertile, apothecia red-brown.
Common on acidic trees, branches and twigs, fences and rocks.
Cortex K+ yellow, UV+ purplish. Medulla KC+ red, P+ orange-red, UV+ ice-blue
Similar: Hypogymnia tubulosa