Mustard powder lichen

Chrysothrix candelaris is a bright yellow crustose lichen that doesn't show any reproductive structures like ascocarps. I thought it was a yellow-painted fence when I first saw it. It needs a few conditions to be met for it to thrive such as a dry shaded area and is usually found on old bark of sycamore, alder, oak, willow, beech, and Pinus species.