Xanthoria parietina ("maritime sunburst lichen") on a marble gravestone, near the coast of Maine. Medieval healers took the color of this lichen as a sign that it was a remedy for jaundice. It is a folk remedy for kidney disorders and several other ailments in parts of Andalucia, Spain. It grows near both the Atlantic and Pacific coasts, but not inland.
Photograph copyright Stephen/Sylvia Sharnoff