Peltigera seneca

Peltigera seneca is a rare species of foliose lichen in the family Peltigeraceae. Native to eastern North America, it was first identified in Pennsylvania's Tioga State Forest, where it grows on humus and mossy rocks. The species has since been reported from 17 localities in South Norway, two localities in South Finland, and a locality in China, extending its known distribution to Europe and Asia. P. seneca is morphologically similar to P. polydactylon, but can be distinguished by its unique chemical profile and genetic characteristics. P. seneca is characterized by its small thalli with narrow lobes and a pale zone on margins of its lower thallus surface. It contains several secondary metabolites, including a distinctive terpenoid not found in P. polydactylon....read more on Wikipedia.