Miscellaneous
Lichens are a combination of fungi and algae living together in a symbiotic relationship. In this symbiosis, the fungi and algae benefit from each other. This evolutionary adaptation allows lichens to grow in some incredibly harsh environments: in deserts and in the Arctic, on barren tundra and on bare rock. Lichens grow in such rugged environments that some early naturalists thought they existed on nothing but air and sunlight.