Lichens are unique organisms that arise from a symbiotic relationship between a fungus and an alga or a cyanobacterium. The fungus provides structural support and protection, while the alga or cyanobacterium produces food through photosynthesis. This partnership allows lichens to survive in a wide range of environments, including harsh conditions such as deserts, tundras, and rocky surfaces.
Lichens play a crucial role in the environment. They contribute to soil formation, provide food for wildlife, and serve as indicators of air quality. Additionally, lichens have been used in traditional medicine and as natural dyes.