Order: Teloschistales Family: Teloschistaceae
Species: Caloplaca cerina
Photos: On Wych Elm. Bantry, Co. Cork, SW Ireland.
Identification confirmed by John Douglass
Thin or areolate light-grey thallus with large (to 2mm) apothecia, discs orange-yellow with thick, +/- crenulate, greyish margins.
Ascus 8-spored, spores polarilocular, 12-15 x 8-10 Ám, septum 5-8 Ám wide 1/3 - 1/2 length of spore. Micro photos below.
Apothecia K+ red-purple
Occurs on both twigs and branches of basic-barked shrubs and trees like Elder, Ash and Sycamore.
Similar: C. cerinella. Smaller apothecia, asci 12-16 spored