Physcia Aipolia is a lichen that is widespread in the temperate zones, boreal and arctic of Eurasia and North America.
Considered lower plants, the lichens are the result of the symbiosis between a fungus and an alga that produces through photosynthesis organic substances necessary for the fungus, which provides water, mineral salts and is also a support for the alga. It contains usnic acid, the substance which, according to some studies, has a strong antibiotic effect.