Caloplaca flavorubescens

This species has a white to yellow-green thallus, smooth, continuous and uncracked, coarsely granular-papillate. Apothecia are up to 3mm diam., with a bright orange disc, scattered to crowded, rounded, usually flat. the lower part of the hymenium and hypothecium have numerous oil droplets. It forms irregular patches between other lichens on bark.

Photo: www.toyen.uio.no