Lichen is an organism that forms a relationship between fungus and a plant. Lichens are found in extreme environments like artic and desert climates, but can also be found on common trees. Lichens mostly reproduce asexually by spores or vegetative reproduction. Also some lichen reproduce sexually like fungi producing spores that come from sexual reproduction. Some lichens are used for perfume products and antibiotics. The picture above is of a lichen I found on a tree at Walmart.