Lichens are composite organisms consisting of a symbiotic relationship between a fungus and a photosynthetic partner, usually either a green alga or a cyanobacterium. Lichens occur in some of the most extreme environments on Earth-arctic tundra, hot deserts, rocky coasts, and toxic slag heaps. They can even survive unprotected in the vacuum of space for a while.
Lichens have provided various uses for humans, including food sources for different cultures around the world, and used in the making of dyes and as a primitive antibiotic. However most of these uses have been replaced by more effective and suitable replacements. Modern uses for lichens mostly involve research and as an indicator species for measuring air pollution and environmental issues.
Lichens can be found all-over in Connecticut. The most common lichens are generally foliose lichens such as the common greenshield lichen that can be found on rocks. Also common is the reindeer lichens, which can be found covering the ground, often in large patches, especially at higher elevations.