Stop 11
Lichens

An easy way to remember what forms a lichen - "Alice Algae and Freddy Fungus took a lichen to each other."

There are bright yellow, red-yellow, and green patches on the rocks along this part of the trail. These brightly colored lichens are actually two organisms - fungus and algae - in one. The association between the organisms within lichens is so complete that scientists give genus and species names to the lichens; the different colors of lichens you see are different species.

Within a lichen, the fungus provides a structural web that protects the alga and provides a suitable environment. In turn, the alga photosynthesizes and provides the fungus with food. When moist, lichen release small amounts of acid that dissolve the rock. This is called chemical rock-weathering and is extremely slow.

Sometimes you can find "moss rocks" for sale or find them out in the wild. This is not moss but lichen. Remember, lichen is a living organism and can die if removed from its natural location.