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.
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.