Chaenotheca furfuracea

Chaenotheca furfuracea is a mealy (farinaceous), bright yellow-green leprose pin lichen. It is in the family Coniocybaceae. This distinctive lichen forms vivid yellow-green powdery crusts on tree bark and produces tiny pin-like fruiting bodies up to 2 mm tall, each with a hair-thin stalk topped by a spherical head. It grows in damp, deeply shaded locations such as tree root crevices and rocky overhangs, particularly in upland areas of Europe where it grows mainly on beeches, oaks, and spruce roots....read more on Wikipedia.