Headache and fever remedies DO grow on trees.
While working with seedlings last March, I developed a definitive hangnail, one that sent jolts of agony up the top of my hand. Remembering a bruise remedy I’d used while camping, I hurried out to the woods near my house and picked a mess of wintergreen (Gaultheria procumbens) leaves. Back home, I broke them to release their juices and simmered them for a few minutes in a cup of water. The continuing pain in my finger made it difficult to wait for the decoction to cool, but when I finally dipped the finger into it, the hurting stopped right away. The hangnail didn’t bother me much for the next couple of house, and then another dunk in the wintergreen brew quieted the pain again until recovery took hold.
At other times, I’ve deadened the sensitive nerve endings of banged knuckles by soaking then for a few moments in a wintergreen decoction, and I’ve found relief for the pain of a sprained ankle by laying a wintergreen-soaked washcloth on it for 10 or 15 minutes.
The paid relief available from wintergreen is related to the presence of methyl salicylate in the plant’s essential oil. Methyl salicylate also occurs in significant amounts in yarrow, black cohosh, and pennyroyal. It is related to salicylic acid, the basis of the aspirin group of drugs. In fact, most commercial methyl salicylate is now synthesized from salicylic acid.
Historically, though, perhaps the most widely used aspirin-like pain-killer was salicin, a compound found in the inner bark of willows (Salix spp., after which salicin was named) and poplars (Populus spp.), both members of the willow family (Salicaceae). When ingested, salicin is transformed into salicylic acid in the stomach. Used both externally and internally, these three related analgesic compounds have a long, worldwide history of relieving pain, lowering fevers, reducing inflammation, and occasionally overcoming milk insomnia.
Stalking the Wild Analgesic
Salicin occurs in the cambium (inner bark) of a tremendous variety of willows and poplars. Willows vary in size from the 80-foot-tall European crack willow (Salix fragilis), which has escaped and naturalized in many areas of the eastern United States, to the foot-tall, ground-covering bearberry willow (S. uva-ursi), a hardy native of the far north that I’ve seen growing wild in New Hampshire’s White Mountains. Although most of the 300-plus species of Salix grow in wet areas along the water’s edge or in bogs, a few prefer well-drained, gravelly spots.
The 30 or more Populus species are distributed widely throughout the northern hemisphere, from tacamahacs (P. balsamifera) in the north to the swamp cottonwoods (P. heterophylla) of the south and including the gray and white poplars (P. canescens and P. alba) that have escaped cultivation wherever they were planted. I’ve found plentiful stands of quaking aspen (P. tremuloides) in the high-altitude canyons of southern Arizona and gray poplars in New York City’s empty lots. Poplars are early forest colonizers, being among the first trees to appear when cultivated land is left to its own devices.
All the birches (Betula spp.) are potential sources of methyl salicylate: black or sweet birch (B. lenta) is the most commonly used natural source because it is more economical to harvest that the wintergreen plant. One way of identifying this tree is by the wintergreen aroma of a snapped twig. Black birches are common in damp soil in rich forests of the eastern United States, where they are native.
Meadowsweet (Filipendula ulmaria), whose white panicles hint of green, and its close relative queen-of-the-prairie (F. rubra), which carries a feathery topping of deep pink flowers, both grow wild through much of eastern America and both contain salicylic acid. Meadowsweet, also known as queen-of-the-meadow, came to the United States from Europe and Asia; queen-of-the-prairie is an American native. Both will escape cultivation of the area is to their liking.
The wintergreen mentioned above, also known as teaberry, grows in north-eastern forests and is a magnificent ground cover whose leaves remain green all winter. Its berries are tasty but are far less effective than the leaves at deadening pain.
Growing Your Own
Most of the plants discussed in the preceding section also do well under cultivation. All of the willows and poplars are fast-growing and, as trees go, short-lived. All are deciduous.
Many poplars have two-toned foliage which shakes a colorful dance during easy summer breezes. Those with “balsam” in their common names also have a pleasant aroma. A poplar can be found for just about any soil condition. They make shade within a few years of planting, but most are brittle enough to snap in only moderate winds. That characteristic along with a spreading root system strong enough to break foundations makes them unsuitable for planting near a house.
Although willows under cultivation prosper in just about any soil, they are best known for doing well in conditions too moist for most other trees. Some willows seem to be perpetually shedding their leaves; for perfectionists, raking is a constant chore, and for those who demand colorful autumn foliage, willows are drab. They often outgrow their planned space. Personally, from the pussy willows to the weeping willows, I love them all. So do many songbirds, who choose willows for nesting.
Black birch, which has bright yellow fall foliage, tolerates just about any conditions from fairly damp to fairly dry soil, shade to full sun, and doesn’t mind winds. Grown from seed or green cuttings, it is hardy to zone 3 and will reach nearly 80 feet in height. Once established, it takes little care.
Filipendulas are perennials that lend themselves well to cultivation, and they’re hardy to zone 2. They are said to prefer moist, even boggy soil. However, I was given chunks of queen-of-the-prairie that were growing along a lake shore. I put them in my rather sandy, well-drained, lightly shaded side garden and they never wilted from drought. The same is true of the meadowsweet I started from seed; they are doing well in average soil. Their only threat in my area is Japanese beetles, which devour the foliage. To retaliate, I make a daily journey with a jar of water to which I’ve added a few drops of dish detergent, and I flick the shiny beetles into the jar for later deposit in the compost pile.
Wintergreen covers acres of deciduous forest floors here in New Hampshire, where the soil is very acid. I root young suckers by clipping them off with a diagonal cut at the base, dipping them in rooting hormone, and burying them up to the lowest leaves in damp, finely ground vermiculite. These have thrived on my lot: my soil, if left alone, barely hits pH 4.5. When I’ve added lime to benefit other plants, wintergreen begins to turn a dark reddish bronze around pH 5.5 and dies before the pH reaches 6.5. While willows grow too much too fast, it takes wintergreen two or three years to cover a foot.
Using Analgesic Herbs
Harvest and Preparation
When harvesting tree bark (here meaning the cambium), be aware that stripping it from the circumference of the trunk can kill the tree. Instead, cut whole twigs or remove larger branches that need pruning anyway. On a good-sized branch, cut or saw short sections of the coarse outer bark, then pry it off with a chisel or knife to reveal the cambium beneath. Cut through the latter with a knife or small saw and remove it in strips, squares, or chips, however it best separates. In small branches and twigs, the inner bark can be reached and whittled away with a jackknife. The cambium can be used either fresh or dried.
When an herb is used medicinally, its tea is named for the way it is made; it’s an infusion or tisane if boiling water is poured over the herb and allowed to cool and steep, a decoction if the herb is put into the water and simmered for a while. Most commercial beverage tea bags hold less than 1/15 of an ounce of herb, but medicinal preparations often are stronger. Your personal taste, the intended use (external or internal), and possibly the price or availability of the herb will determine the exact amounts to use. A strong tea for external use can be made with up to a full ounce of fresh herbs, or half an ounce of dried, per measuring cup of water.
Infusions of flowers and leaves are best made a pint at a time; they don’t keep well and are best when fresh. Pour 2 ¼ cups boiling water over the herbs in a ceramic, glass, or stainless steel container, then cover immediately, steep at least ten minutes—the longer it steeps, the stronger it becomes—and then strain. Refrigerate any unused brew, but discard it within a few days if unused.
To make a decoction from a plant’s tougher parts—bark, hard stems or twigs, and roots—bring 2 1/3 cups of water and plant parts to a gentle boil in a covered noncorrodible pan. Reduce heat and simmer for at least half an hour, then strain.
Essential oils of wintergreen and sweet birch are available in specialized stores. These are highly concentrated, containing up to 99 percent methyl salicylate, and they are dangerous irritants, externally or internally. Do not try to use dilute essential oils as a substitute for water extracts (infusions or decoctions) or plants, for tea or for external use. Research indicates that a toxic dose of methyl salicylate can be absorbed through the skin.
Ingest with Care
The plants discussed here contain many other compounds besides those related to salicin, and their effects are beyond the scope of this article. It would be wise to consult a qualified health practitioner before undertaking any internal medicinal treatment with these herbs.
Note, however, that the amount of active ingredient you ingest from a tea brewed from wild or cultivated plant materials is less than you’d get from aspirin. I find that a mild tea brewed, for example, from the inner bark or twigs of black birch is quite an effective analgesic. On nights when I feel pressured and wide awake, I like to make a salicin tea from willow bark to drink before going to bed—I sleep away the rest of the night and wake up bright and ready to go in the morning.
The appropriate strength of a tea made for drinking depends on personal taste and the desired effect. Different people will react differently to the same combination of compound and dose, so calibrate your consumption according to the messages your body sends. If you experience nausea, ringing in your ears, or deafness, cut back on the amount you’re taking. If you experience stomach pain or discomfort after taking such a tea, try eating food or drinking milk before taking the tea the next time. Strong teas should be drunk in small doses—perhaps a third of a cup every two or three hours—to minimize stomach upset.
Anne Westbrook Dominick is a freelance writer and herb lover in Hinsdale, New Hampshire.