What Is Usnea Lichen: Does Usnea Lichen Harm Plants

What Is Usnea Lichen: Does Usnea Lichen Harm Plants

By: Mary Ellen Ellis

You may not know yet what it is, but you have probably seen usnea lichen growing on trees. To better understand this fascinating lichen, check out this usnea lichen info.

What is Usnea Lichen?

Usnea is a genus of lichen that hangs in clumps of filaments on trees. Lichen is not a plant, although it is often mistaken for one. It is also not a single organism; it is a combination of two: algae and fungi. These two organisms grow together symbiotically, the fungus getting energy from the algae and the algae getting a structure on which it can grow.

Usnea is most often found in coniferous forests.

Does Usnea Lichen Harm Plants?

Usnea lichen does not cause any harm to the trees it grows on and, in fact, usnea lichen in landscapes can add a moody and interesting visual element. If you have usnea in your yard or garden, consider yourself lucky. This lichen grows slowly and is not found everywhere. It actually absorbs toxins and pollution in the air, so you get the benefit of cleaner air by having it make a home in your garden.

Usnea Lichen Uses

Usnea lichens are actually quite useful. They have been made into medicines and home remedies for hundreds of years, but have other uses too:

Dyeing fabrics. You can soak and boil usnea lichens to create a liquid that will dye fabrics a beige color.

Sunscreen. These lichens have also been made into natural sun protection because they absorb ultraviolet light.

Antibiotic. A natural antibiotic in usnea lichens is called usnic acid. It is known to work against several types of bacteria, including Streptococcus and Pneumococcus.

Other medicinal uses. The usnic acid in usnea lichen is also known to have antiviral properties. It can kill protozoans, which can cause illness. Usnea also has anti-inflammatory properties and may even be able to kill cancer cells.

Usnea lichen is harvested all the time to be used as an ingredient in a variety of products, from toothpaste and sunscreen to antibiotic ointment and deodorant. You might be tempted to harvest the usnea from your yard for some of these uses, but keep in mind that it grows slowly so it’s best to take it from branches or pieces of bark that have naturally fallen from trees. And, of course, never treat yourself with an herbal remedy without speaking to your doctor first.

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Looking at Lichens

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Almost everyone is familiar with the term lichen (pronounced "like-in"), but few people know much about these small plantlike organisms. Lichens grow throughout Missouri and are a major contributor to the mosaic of colors in our natural landscape. They grow on all types of rocks and trees in a variety of habitats, and they are an important component of healthy habitats.

Lichens often are lumped with mosses or other small plants, although they have little in common except size and habitat because lichens have no roots, stems or leaves. Unlike most animals and leafy plants, a lichen is a fusion of two unrelated organisms. Every lichen is a combination of a fungus and algae or algaelike bacteria. Bread mold, morel mushrooms or the toadstools that sometime grow in our lawns are some familiar fungi. Algae are most familiar to us as the green scum on ponds and other slow-flowing waters.

The fungi and algae in lichens are usually different types from their free living relatives. While almost every lichen species has a unique fungus component, we often see the same species of algae in more than one type of lichen.

A lichen looks and behaves differently than either of its components do independently. The algae and fungi in a lichen combine to form something that is capable of reproducing itself, has a distinct appearance and range of habitats and in every other respect acts like a distinct plant. Certain lichens are found only in specific habitats, and some only grow on one kind of tree or rock. On the other hand, a single boulder or tree trunk in a natural habitat may support 30 or more different kinds of lichens. Much of the color we see on bluffs and rock outcrops is due to lichens.

The relationship between the algae and the fungi in a lichen is complex and not completely understood. This relationship also differs among different lichens. In general, lichens take their shape from the fungus component, within which are zones containing algae. Many lichens have brown or black disks on their surface-these are the spore-producing parts of the fungus.

The lichen fungi get nutrition from the algae, which use sunlight and simple chemicals to produce food. How much this relationship is mutually beneficial and how much is parasitic is uncertain. It is interesting, however, that lichens flourish in places where both algae and fungi are rare.

Most lichens grow slowly and many grow only in a narrow range of habitat conditions. This makes them especially susceptible to habitat disruption. Many species are sensitive to air pollution, and lichens are used throughout the world to assess and monitor air quality. Despite these sensitivities, lichens are capable of growing in the harshest of natural environments. They live in fresh and salt water, deserts, tropical forests, alpine summits and even in Antarctica.

Because of the slow, uniform growth rates of lichens, scientists use some species of them in polar regions to establish the time and speed of glacial retreat. Some tropical lichens even grow on the shells of beetles and tortoises. In Missouri we have nearly 500 different species of lichens, including some found nowhere else in the world. Lichens are found in every square mile of the state, although in urban areas they are fewer, smaller and easily overlooked.

Lichens often contain bitter chemicals and are not a major wildlife food source, but they are an important component of the food chain. Land snails and many other small animals feed on lichens. In northern tundra, lichens are a staple winter food of caribou and reindeer. Locally, deer sometimes consume small quantities of lichens, especially in winter.

Several birds, including the ruby-throated hummingbird, eastern wood pewee, and blue-gray gnatcatcher, use lichens in nest construction. One of Missouri's most colorful warblers, the northern parula, prefers either old man's beard lichen (Usnea) or Spanish moss for its nest. Spanish moss is a flowering plant related to the pineapple and does not grow as far north as Missouri. Local populations of northern parula warblers often use the abundance of old man's beard lichens in healthy Ozark woodlands.

People have used lichens since antiquity as medicines, dyes, food, decoration, perfumes and even crude clothing. The subtle browns of Harris tweed fabric come from dyes made of lichens. Artisans in Europe have used lichens for centuries to produce a vivid purple dye. The acid sensitive litmus paper that many of us remember from high school chemistry classes also is made from lichen extracts. Some antibiotic salves also contain lichen extracts.

Although not poisonous, lichens generally are not palatable to humans, and some people have developed rashes from prolonged contact with certain lichens. People use a few species for food, especially during hard times, and the "manna from heaven" described in the Bible is thought by some people to be a desert lichen. In Asia, a large, saucer shaped lichen called a rock tripe is often fried and eaten.

Many lichens are common throughout Missouri, and a few are so distinctive or colorful that they are noticed by those who regularly go outdoors. Even though they often cover tree trunks, lichens are not tree parasites and do not damage trees. Lichens play a critical role in mineral nutrient cycling in many forests. Certain lichens are even capable of using, or "fixing," atmospheric nitrogen-an unusual trait shared only by a few plants, such as legumes.

We are just beginning to understand the diversity and importance of lichens in our natural systems. The Conservation Department, in conjunction with researchers from The Nature Conservancy and the Missouri Botanical Garden, is studying the lichens of Ozark woodlands as part of its Missouri Ozark Forest Ecosystem Project (MOFEP). This and other ongoing work on Missouri lichens has resulted in the discovery of several species new to science, including two that have been named after the state of Missouri.

You can identify three general types of lichens by their shape and appearance. Lichens with a well-developed, three-dimensional growth form, often looking like miniature trees or columns, are called fruticose lichens. The best known local examples of fruticose lichens are British soldiers, old man's beard and reindeer lichen. Fruticose lichens are often the first to disappear when a natural habitat is disrupted.

Probably the most common type of lichen in Missouri is the foliose lichen. These are flat, typically green or gray lichens that can be abundant on trees and rocks, especially in the Ozarks. These lichens come in a wide range of sizes, with some species less than 1/4-inch wide and others that are more than 10 inches wide.

Crustose lichens are the most diverse and least noticed group of lichens in Missouri. Just as their name implies, crustose lichens often look like a thin crust on rocks, soil, trees, fenceposts, shingles and old, rusted iron on bridges. Some crustose lichens even grow inside rocks, occupying the microscopic spaces between rock crystals.

Most crustose lichens are small and drab and require a microscope for identification. Few have common names, although the bright orange fencepost lichen (Caloplaca microphyllina) is an exception that provides a splash of winter color on weathered eastern red cedar and Osage orange posts in prairie and farm areas. A few types of crustose lichens are among our most adaptable species and even thrive on concrete in downtown St. Louis and Kansas City.

Important yet tiny, colorful but often overlooked, lichens play an unusual role in our environment and in human consciousness. We seldom notice them, yet our landscape would seem less rich and varied without them, and many plants and animals indirectly depend upon them in our natural systems.


In adult gardens, gentlemen live on trees. They also (but somehow in their own way) like apples, pears, cherries, plums… Here are Polypores mushrooms-although they have a romantic appearance and smell good, but they are definitely pathogenic: they decompose wood with mycelium. For which they are subject to destruction. However, we usually see the fruit body in the form of known shelves or “ears”, and not the mushroom (mycelium), which is much larger and more secretive .

If you remove and treat with vitriol the place where the fungus grows, you can not say that the mushroom is defeated. It is necessary to monitor the problem area and achieve sustainable regeneration of tree tissues in the affected area – this will be a sign of the tree’s victory over the fungus. If regeneration does not occur – and this is evident from the fact that the callus does not grow on all sides of the cleaned surface of the tree – then the fungus most likely takes over, and the tree is not able to overcome it in this place. Only cardinal surgery will help here.

If we want to get a garden with maximum impact and productivity, then of course we must fight all those who sit and ride on our trees in all possible ways, not excluding chemistry. We have quite old trees in our garden. I conduct regular selective furrowing of trunks and skeletal branches with a hacksaw blade. This process is akin to changing the upper protective epithelium in humans. It can be washed off with alcohol and other solutions, scrubs, or you can just scratch it. Both are good, as you know, in moderation.

As a result of furrowing, the area of the bark is actively rejuvenated. Stripping and partial removal of a layer of moss, lichens and other things as if gives the tree a certain head start in the system of biocenosis tree-moss, tree-lichen.

I don’t like whitewashed trunks in the garden. I love mossy and lichen-covered trees, and I see beauty in them. There is the idea that mosses and lichens possess anti-bacterial and antibacterial properties. Thus, sphagnum and Usnea growing in forests were used during wars as an absorbent wound-healing material. Gardeners know that it is best to store bulbs and cuttings in sphagnum. Symbiosis with a tree consists in the suppression of putrefactive, pathogenic microorganisms by a colony of moss or lichen. But this requires further research.

Knowing that lichens are indicators of fresh air, I inhale it with pleasure and watch with concern how they feel, whether they bend. I try not to use chemistry as long as possible. We are not so much afraid for ourselves as we are happy to see butterflies, ants, and snails in the garden. My plan for tree care is to maintain a balance between utility, expediency, and the environmental side of things.

The above has to do with an adult, I would even say, partly old garden. A young garden should be cultivated using all known modern agricultural techniques, using poisons to varying degrees, bleaching the trunks from burns, etc. The strength of a long-lived garden is laid in youth.

So, measures for the care and maintenance of garden tree trunks:

  • filing and pruning all unnecessary items,
  • detection of necrotic areas of the trunk, with fungi, frost-bites and other pathologies,
  • cleaning the edges of all damaged surfaces, cutting and scraping crooked grafting knife modified wood,
  • thorough painting, filling and sealing of wounds and cavities in good weather,
  • furrowing overgrown with moss and lichen parts of trunks and sections of old sections, tightening holes and wounds of previous years.


Add Usnea to Your Herbal Medicine Chest to Fight Infection

Usnea (Usnea hirta and others) is a common, charismatic lichen found in Cascadia as well as many other forests across the globe. Its netted, hair-like body is created through a symbiotic relationship between algae (Chlorophyta) and fungus (Ascomycota). There are many species of usnea, but the one of highest medicinal value, sometimes called Old Man’s Beard, is identified by gently pulling apart a major branch of the lichen. If you have the correct species, the green outer layer will break (algae crust) and a stretchy white band of the inner layer (the fungal partner) will remain in tact. Usnea is very sensitive to air pollution, which is why you’ll rarely find it growing in cities. For me, abundant levels of usnea indicate I’m in a healthy, mature forest where it might be safe to harvest other plants as well (under stringent wildcrafting ethics of course!)

People around the world have used usnea for thousands of years for dying textiles, as cosmetic additives, in care for livestock and agricultural crops, and for human medicine. However, it escapes many herbal traditions that focus only on vascular plants. In Chinese medicine, usnea’s cool, drying tendency helps the body clear damp heat. It contains usnic acid that disrupts the cellular mechanics of Gram-positive bacteria, including the nasty stuff like Streptococcus and Staphylococcus, but leaves a lot of our natural microbiota unharmed. It’s especially powerful medicine for dampness or inflammation in the respiratory or urinary tract. Topically, usnea is also effective against MRSA, fungal infections including candida, and relieves mastitis in livestock (or humans).

Whenever on a walk in the woods, I’m always on the lookout for a fresh clump of usnea that has fallen to the forest floor. I find the best scores in fall when the rain has knocked fresh clumps down but they haven’t yet had months to deteriorate. Given usnea’s sensitive nature and slow growth pattern, it’s unacceptable to harvest usnea from a standing tree. After it has fallen to the forest floor, usnea holds up remarkably well due to its antibiotic and antifungal properties. Under cover and placed on paper or cotton, it dries rapidly and is sometimes ready to be packed away by the time I get home from my woodland adventure.

Usnic acid is not very soluable in water. It’s slightly better extracted in alcohol. It’s efficiently extracted in oil. However, the polysaccharides, which are the immune-stimulating constituents found in the white inner cortex of the lichen, are best extracted with heat. Therefore, different extraction methods are required depending on what actions you desire. Similar to mushrooms, a mother extract (high alcohol by volume extract followed by hot water extract) is the best way to benefit from both usnic acid and the polysaccharides. Read “Fungi Medicine: Mushrooms Offer Real Theraputic Value” for a more thorough discussion of this technique. The mother extract (20-40 percent alcohol by volume) makes a great spray for the back of the throat when that first tickle of a cold or flu is felt or if swollen lymph nodes are present. Spritz several times throughout the day and you may just nip it before the bad bacteria takes hold!

For the highest strength of usnic acid by volume, use refined oil of your choosing for an oil extraction. Place covered usnea oil in warm, sunny spot for several months. Sun is not always easy to come by in Cascadia, so I like the top of the water heater for oil extraction. This method is great for topical applications. You can also try it as a mouth rinse if you’re using oil pulling techniques. Creating a salve is the best way to store usnea oil for easy use.

I use usnea mother extract spray for the fungus that hangs out between my little toes the alcohol helps dry them out. But if I encounter a dry burn, psoriasis, or subcutaneous MRSA sore, I use usnea oil. I read recently that usnic acid absorbs ultraviolet light, which makes me think usnea oil would be an effective sun block. I haven’t tested this yet so if anyone tries it, let me know how it works!

My favorite use for usnea is as menstrual pads or rustic tampons. The high absorbency of the usnea combined with the antibiotic effect make it a premium choice for my feminine hygiene needs. I first started using usnea when a surprise moon caught me off guard in the forest. I used usnea as an emergency alternative. Now, I use it on a regular basis because of its effectiveness. Plus, I enjoy the ritual of burying or composting the reddened usnea, returning my blood to the earth to nourish my garden or the forest. Give it a try using a dry, sculpted clump on a lighter day and see how you like it!
References:
Hinkle, Irene. 2012. Lichenology workshop at the Radical Mycology Convergence.
Rogers, Robert. 2011. The Fungal Pharmacy. North Atlantic Books, pp 486-491


Watch the video: Usnea - Lichen for super healing!