Lichens

例句：

1. 1.Lichens are fascinating organisms that can be found on rocks and trees.
   地衣是有趣的生物，可以在岩石和树木上找到。
2. 2. The lichens on the cliff face provide a unique habitat for many species of birds.
   悬崖上的地衣为许多鸟类提供了独特的栖息地。
3. 3.Lichens have been used in traditional medicine for centuries as a source of medicinal compounds.
   地衣在传统医学中被使用了几个世纪，作为药用化合物的来源。