lichen
noun /ˈlaɪkən/, /ˈlɪtʃən/
/ˈlaɪkən/, /ˈlɪtʃən/
[uncountable, countable]- enlarge imagea very small grey or yellow plant that spreads over the surface of rocks, walls and trees and does not have any flowers
地衣 compare moss词源early 17th cent.: via Latin from Greek leikhēn.