Appalachian Tree Brown-Shield

Melanohalea halei is a species of foliose lichen in the family Parmeliaceae. The species was first described in 1966 by the Finnish lichenologist Teuvo Ahti from specimens in eastern North America that had previously been misidentified as Melanohalea olivacea. It is distinguished from similar brown foliose lichens by its yellowish- to greenish-brown colour, a thallus that lies closely against the bark and develops tiny side lobes toward the center, and a medulla that reacts K+ (yellow0...