Now that the rains are here, goldenback ferns (Pentagramma triangularis) are starting to emerge. Their lacy green triangle-shaped leaves are emerging from rocky cliffs and stream banks. The leaves alone are quite distinctive-looking, but if you aren't sure what you're looking at just flip one over. The entire underside of the surface is covered with tiny spores like a layer of fairy dust. Usually this turns the leaf bottom a startling pale-golden color, but sometimes it can appear more white or mature into a duller brown.
If you want a little forest decoration while out hiking, you can pluck a leaf and carefully place the spore-side down against your clothing (or skin) and give it a quick smack. Often you'll have a perfect, pale-gold fern print left behind.