Usnea is a lichen that grows in the forest, usually near water. Though lichens appear to be single plants, they are really a combination of fungus and algae that grow together for their mutual benefit.
I'm sure most of you have seen usnea and just didn't realize how valuable it is! It's often called "Old Man's Beard" and hangs in long bunches from high up in the trees. There are many tree lichen out there in the forest, some are toxic, so make sure you know what you are harvesting. Usnea is high in usnic acid so go lightly on tea with usnea, if you are sensitive to acid in foods. It is anti-viral, anti-biotic, anti-fungal. Usnic acid, which is the main medicinal ingredient, is not water soluble so is best used in oils, vinegars, or alcohol to make salves, soaps and tinctures.