Harvest Usnea Lichen For Natural Immune Support

Usnea lichens, aka "old man's beard," are as beneficial as they are prolific. Here's how to identity, harvest and prepare this foraging find for medicinal use.

by Melissa Calhoun
PHOTO: billyfam/Adobe Stock

Lichens are two organisms sharing one body: an alga and a fungus. So it may not surprise us to learn that the benefits of usnea lichens share similarities with many of the mushrooms (fungi) popularly used for immune health and nourishment.

There are usnea species in the Appalachian region that are found thriving in cooler and wetter forests. They grow high in the air on older, dead or dying tree limbs. These gorgeous tiny lichens are slow to grow and hard to reach, but such limbs can be found having eventually dropped to the ground.

A hike through the right woods can make for a delightfully slow and ethical harvest.

Usnea lichens live in the air and provide a benefit to the lungs. Its habitat may be threatened in your area, so harvest with nuance and respect.

Where to Find Usnea

There are several species of usnea found all over the globe and within the U.S. In the Pacific Northwest, Usnea longissima are found in long bushy forms. In fact, with the common name “old man’s beard,” the forms are long enough to resemble Spanish Moss, a cousin found in the southern states.

Spanish Moss, however, is not an usnea species and is not recommended for the uses we’ll discuss here. But its morphology is familiar to many and a good way to begin picturing this family of lichens by association.

Subscribe now

Usnea can be found on a variety of trees. Here in Kentucky I find it on trees like thorny locust and ash, usually 10 years or older, who have some dying limbs and a lot of height. Sometimes small clumps appear on the black rot of the failing peach orchard. I’ve hiked trails in the Daniel Boone National Forest that seemed to rain usnea when the struggling hemlocks yielded their domination to the changing ecosystem.

I don’t think usnea requires a tree to be dead or dying in order to anchor on its limbs, and I certainly don’t see it causing trees harm. Some even consider it a harbinger of air pollution and a forest protector. These “lungs of the forest” extract environmental contaminants with their air use.

In fact, if air pollution is a concern in your area, beware toxins will be contained in the lichens.

But I have always found it in abundance in places that rapid tree loss might feel overwhelming due to disease or heavy insect pressures. Here, usnea offers a comforting treasure in stark times.

Identifying Usnea

One distinguishing field test to find out if your lichen is an usnea is to slowly and gently create tension along a longer section of an individual “arm” of the  lichen. Hold this thicker strand between thumb and forefinger of each hand and pull them evenly apart. This should reveal a small inner “string” running inside the outer layer you just tugged.

Fresh or moistened usnea easily yields its outer “sheath” to reveal a white elastic “core” that looks like a string inside the tube of its algal “skin”(see picture).  Spanish moss also has this elastic string inside, but it is black, not the white or cream color we’re hoping for with usnea. The somewhat toxic wolf lichen of the Pacific Northwest does not have the inner string.

Many other lookalikes have flat (rather than tubular) strands. But if you look closely and patiently, and wait to prepare it until you’ve consistently identified it and had your findings corroborated by a more knowledgeable plant person, the rewards are bountiful.

usnea lichen
Melissa Calhoun

Harvesting Usnea

Hiking a forgotten deep woods trail is a great anytime pick-me-up, and it’s the best way to discover usnea, too.

The likelihood of abundant usnea increases in climates with more fog, rain and humidity. Watch the ground for a lichen that looks out of place, like it fell. When you pick one up, an usnea will be unattached to the ground, loose or “stuck” on a fallen limb.

First, do the “stretch test” described above. If that white elastic fungal core is there, look up. If you see loads of lichen hanging high above, you’ve found a reliable place to harvest.

If you don’t see fuzzy silhouettes outlining many limbs above, consider this a spot where usnea is either overharvested or too rare to be responsibly gathered. A good rule of thumb among herbalists is, if we have any doubt about abundance, we consider gathering no more than one fifth of the observable population at hand.

Rather than taking the living usnea from high above, come back to this spot again and again. Just harvest the fallen clumps the wind sends you year round. (Hint: take the day and head out after a big windy storm).

Using this harvest method, you’ll eventually collect the amount that’s right for you to make the medicine you need. But even a pinch or a handful is enough. You can even stuff them in your pocket and forget about them when you get home.

A week or two later when you venture out again, a perfectly dried clump will await you in your jacket, to add to it if you’re lucky!

Read more: Don’t be afraid to forage hedgehog mushrooms.

Preparing Usnea

I’ve heard folk history of wilderness survivalists and soldiers alike packing open wounds with usnea with great results. But let’s not hope you come to that situation on your restoration forage hikes this year.

Proper preparation, like harvest, also requires some nuance. Combining both water and alcohol extracts will yield a wider range of potential benefits for your body.

Use the whole lichen to concoct your brew. There’s no processing required for either fresh or dried (that’s the easy part). Usnea has a long traditional history of use for a wide number of ailments and is still used in many cultures around the world. Its preparation techniques, as a result, are also widely variable and may depend on the tradition, targeted ailment or tools at hand when the need arises.

If you’re experienced with successful herbal oil infusion processes, dried and powdered usnea will serve you well as an ingredient in your next salve. But tinctures are simpler and can be taken internally, and a dilute tincture can also be placed on the skin for topical woes!

Making Tea

For the beginning home medicine maker, however, I recommend a hot tea that is not strained, followed by the addition of alcohol by an amount to preserve your extract. Twenty to 30 percent pure alcohol by volume will keep an extract shelf-stable. You can easily achieve this by purchasing grain alcohol or any 190 proof liquor.

Measure the amount of just-boiled water it takes to cover the amount of lichen you’re steeping. Then add half as much grain alcohol as this water amount to the mixture. This yields an about 25 percent alcoholic solution—plenty to preserve and further extract alcohol-soluble constituents.

Cover your container with a tight lid. Then invent some safe way to occasionally give warmth to the mixture (i.e. do not allow flame or high heat to contact alcoholic vapors). A slow cooker with a sous vide setting or a very low double boiler setting might work for you.

Heat until hot to the touch, then set aside. Repeat the next day. Do this heat application three to five times, then set it somewhere you will pass by every day. When you notice it, give it a quick shake and think about the lovely adventure you had under the trees.

Wait several weeks or months to strain—at least until the mixture both smells and tastes like a divine mushroom.


If you prefer not to ingest alcohol, you can still prepare usnea as a decoction, which is just what herbalists call making concentrated tea. Your usnea tea will be more potent and effective when brewed over low heat for a prolonged period of time.

Place usnea in a pot or double boiler and cover it with about three times as much water as it would take to soak it. Use the lowest possible simmer setting to heat, covered, until the liquid is reduced to about a third of its original volume.

Ideally your heat is so low that this takes a day or more.

Store strained concentrate in the fridge and drink by the ounce two to five times per day until symptoms are gone. If you have extra, you can freeze it for another sick day or skin ailment. You can also freely adjust this recipe for flavor and strength, and consider powdering the lichen for a stronger and faster extraction.

As you begin to employ this great helper in times of need, taking notes on each recipe will help you study variations in effectiveness and palatability. The goal is to respectfully and effectively prepare so as not to overuse this slow-growing herb.

usnea lichen
Melissa Calhoun

Usnea’s Benefits

When extracted with heat, water and time, then used internally, like many mushrooms, usnea’s fungal components may exercise our immune system function and awareness (like a fire drill without the fire). Usneas also contain water-soluble sugars that feed our bodies’ natural cellular functions, aiding in digestion and immune strength.

But we can get these same benefits from much more easily obtained mushrooms such as turkey tail, oyster, shiitake and chicken of the woods.

So let’s consider usnea’s other actions for our niche use of this powerful lichen and appreciate the extra goodies that come with it. Usneas also contain alcohol-soluble acids that can harm bacteria, viruses and fungi. A super-powered herb for pandemic times, it boasts the additional actions of mild expectorant and inflammation mediation. Consider usnea a “first responder” for  immune support in early stages to prevent suspected infection, especially indicated for sinus, respiratory, urinary and fungal situations.

Usnea is also renowned for wounds and skin ailments, especially fungal ones.

Based on these multiple applications, researchers have decided to test usnea’s protection against a long list of harmful biotic agents. This is science catching on to ethnobotanical history. You can find a simple but detailed list of studies from the generously prolific herbal educator Rosalee de la Foret.

The necessity of deeply exploring our debt and privilege to receive and share herbal knowledge with our foregone and current indigenous herbal practitioners here is utmost. Like countless other botanical friends, usnea’s amazingly multi-pronged existence may become so desired as to be exploited on the global market very soon, if not already.

Respectfully and humbly approach herbalists who are culturally native to your area for their advice on both the ethics and practical applications of gathering and preparing usnea. Don’t overharvest, and likewise, don’t overuse usnea. Use only in small doses and only when illness seems threatening.

If it’s not raining in your neck of the woods, email me and I’ll share:)

Leave a Reply

Your email address will not be published. Required fields are marked *