Parmelia marmariza

Parmelia marmariza is a species of corticolous (bark-dwelling) foliose lichen in the family Parmeliaceae. Originally described from Japan in 1890, this lichen is widespread across East Asia, occurring in Japan, Taiwan, Nepal, and parts of China, where it grows in humid temperate to subtropical forests. The species forms whitish to greenish-grey crusty growths closely attached to tree bark, characterised by lobes with conspicuous black-rimmed margins and numerous small pale pores that often merge into a network of ridges. It is distinguished from related Asian species by its dense covering of small raised pores and its chemical composition, which includes several diagnostic compounds detectable through standard lichen chemistry tests. ...read more on Wikipedia.