Order: Lecanorales Family: Ramalinaceae
Photos: On bark. Droum Wood, Co. Cork, SW Ireland.
Very variable. Whitish-grey thallus with numerous small, black pycnidia. Often infertile but when present the apothecia are pinkish to light brown, often pruinose and becoming convex and distorted. Thin, lighter coloured margins that darken with age. The spores are 1-septate, 8-15 x 2-4 Ám. Microscope photographs below.
Thallus K+ yellow, pycnidia walls K+ purple.
Found on the drier side of acid-barked trees and wooden posts, rarely on shaded rocks. Moderately pollution tolerant.
Similar: Cliostomum tenerum is found on acidic coastal rocks