Xanthoria Polycarpa, Sunburst Lichen

Day 176: From the Latin "xanthus" meaning "yellow," the Xanthorias are a very distinctive genus of foliose lichen and, at least in the Pacific Northwest, are most commonly found growing on hardwood bark, generally in sunny, open locations. Xanthorias also colonize on rock. Their colour is striking, and often gives rise to expressions of repugnance in the uninitiated, on the order of, "Ewwww! What's that orange stuff all over the trees?" On closer examination, the structures of the lichen become apparent: a foliose thallus dotted with raised apothecial disks. Xanthoria polycarpa occurs farther inland than the very similar X. parietina, although both are primarily coastal species. X. parietina is not known to occur in Washington.