HomeNewsThe Lungs of the Forest: Usnea Lichen

The Lungs of the Forest: Usnea Lichen

Usnea is a genus of pale greyish-green beard lichen that grows like tassels hanging off trees. You have probably seen it decorating our local forests. In North America, usnea grows along the Pacific coast from northern California to southern Alaska. It thrives in the moist and cool forest of the Pacific Northwest, and over 600 different species of usnea have been identified. While appearing to be a single plant, this interesting organism is a symbiotic combination of fungus and algae growing together. It is similar to other classes of lichen, but the distinguishing feature is that the central branches of usnea are slightly elastic. This genus has existed for at least 34 million years, as indicated by fossil records dating to the late Eocene period. The longevity of usnea likely arose from the adaptive advantages from the elastic central branch, which has helped the genus thrive in many diverse ecosystems and climates. Usnea is commonly known as “The Lungs of The Forest” because its growth is a good bioindicator of forest health. Usnea is sensitive to air quality, and the branches only grow longer than 10 cm in relatively healthy ecosystems. 

The dead of winter can be a forager’s nightmare. However, usnea is one natural remedy that allows for year-round harvesting. So, never fear, usnea is here! The healthiest specimens of usnea are found away from industrial and residential areas due to usnea’s ability to absorb environmental toxins, such as sulphur dioxide. Healthy usnea is light green and slightly elastic. 

Like any moss, lichen, or fungus, usnea should never be harvested directly off a tree. Usnea has a modest growth rate, and the lichen itself is beneficial to the forest, so the naturally growing usnea should never be disturbed (except for picture-taking). Look for usnea specimens on fallen branches, especially after a strong wind storm. That way, the forest will remain preserved for the next foragers or animals looking to harvest. To process your ethically-harvested usnea, allow the collected plant matter to dry out completely. Then, grind the dried usnea into a fine powder. The cell walls are rigid, so processing must involve chopping, grinding, and mashing to make the medicine more bioavailable. Fresh usnea can also be made into a dual-extract tincture by soaking it in alcohol and using hot water extraction methods, but I don’t have time for that. Usnea powder is much more convenient; it can be applied topically to wounds, used in a healing bath for skin ailments, and might even be effective for acne treatments and bug bites due to its antimicrobial qualities. 

Usnea has several industrial and medicinal uses. The active ingredient is usnic acid – known to be effective against bacteria responsible for staph infections, strep throat, and pneumonia. The presence of usnic acid makes usnea a potent herbal treatment for sore throats and skin infections. Usnea can be used to make dyes in the textile industry, and usnic acid is in cosmetics and deodorants for its antifungal and antimicrobial properties. Usnea has a history of medicinal and practical use around the world. It has been used medicinally for centuries in Traditional Chinese herbal medicine. Also, the Haidi nation on the west coast of British Columbia would utilize usnea threads to strain impurities out of hot tree sap for medical treatments. Modern-day herbalists champion usnea as a respiratory and skin medicine; dried usnea can be applied to external wounds and skin infections, and usnea tincture can be taken internally to treat respiratory infections and boost the immune response. 

As with any natural remedy, one should exercise caution when using usnea; usnic acid can be potentially toxic in higher doses when taken internally. Usnea medicine should not replace modern-day health interventions, and internal use should occur only under the supervision of a trained professional.

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