Tree Moss on Downed Log
Hiking in the Lost Creek Wilderness of Colorado, I came across some interesting moss growing on a dead conifer. The moss is actually a lichen called “Usnea,” which is the name of several species of lichen that grow hanging from tree branches, resembling greenish gray hair. It is commonly called Old Man’s Beard, beard lichen or tree moss. Lichens are not parasites. They are actually two organisms living in a symbiotic relationship: a fungus and an alga; the original odd couple. Biologist love to use lichens as a perfect example of symbiosis: when two organisms live together and mutually benefit. The algae uses the sun to photosynthesize while the fungus provides the support structure and water and mineral transport system.
