li·chen
noun/ˈlaɪkən/, /ˈlɪtʃən/
/ˈlaɪkən/, /ˈlɪtʃən/
[uncountable, countable]- a very small grey or yellow plant that spreads over the surface of rocks, walls and trees and does not have any flowers
enlarge image地衣 Word Originearly 17th cent.: via Latin from Greek leikhēn.