Lichens are unlike any other organism on earth. Their structure is unique: a symbiosis of two organisms — a fungus and algae. Lichens are not plants, so they do not produce seeds. Lichens can survive in some of the most barren and severe regions of the world. They tolerate extreme cold and dry conditions through dormancy and the ability to recover quickly when conditions are favorable. Although lichens can grow in regions with more rainfall, they actually require little rainfall to survive.
