Aspen

Aspen trees are unique because an entire grove shares one root system, which stems from one parent tree. Find out more about this medicinally useful plant.

Quick Facts
General Information
  • Common name(s)Aspen, quaking aspen, trembling aspen, white poplar, mountain aspen
  • Scientific namePopulus tremuloides
  • Geographic distributionEurope, North America
  • Plant typeTree
  • Native regionNorth America
  • Main producer(s)United States of America
  • Main Economic UseTimber industry
Medicinal and Nutritional Information
  • Medicinal actionAnalgesic
  • Key constituentsSalicin, populin
  • Medicinal rating(2) Minorly useful plant
  • Safety rankingUse with caution
Buying
  • Where to buySpecialized health stores, Online herb stores
Growing
  • Life cyclePerennial
  • Harvested partsBark
  • Light requirementsFull sun
  • Growing habitatCool temperate regions
Additional Information
  • Other usesPaper, Cosmetics, Timber
Aspen

Aspen trees, also commonly called "quaking" or "trembling" aspens, are the most widely distributed tree species in North America and have been used as both a timber source and a remedy to treat rheumatoid arthritis, cystitis, diarrhea, and the common cold by native populations since time immemorial.

Medicinal and Nutritional Information

Quick Facts (Medicinal and Nutritional Information)
  • Medicinal actionAnalgesic
  • Key constituentsSalicin, populin
  • Medicinal rating(2) Minorly useful plant
  • Safety rankingUse with caution
Aspen

Health Benefits of Aspen

The anti-inflammatory, astringent, and antiseptic properties of aspen extract have been used mainly for:

  • Relieving inflammatory pain
  • Soothing the symptoms of coughs and colds
  • Relieving headaches

Additionally, the traditional uses of aspen include:

  • Treating chronic skin conditions like eczema or acne
  • Speeding up the healing of frostbite

How It Works

The anti-inflammatory and antiseptic action of aspen bark extract is produced by salicin, a compound that is chemically similar to the active ingredient of aspirin. Salicin can inhibit cytokines, leukotrienes, and prostaglandins, three body-produced hormones that cause the pain, throbbing, or redness related to inflammatory processes. Experts believe that salicin is stored in aspen bark as a natural defense against parasites and other infestations, since its astringent qualities keep them away. The medicinal properties of aspen trees is additionally supported by the unique mixture of tannins, triterpenes, and other compounds found in their bark extract. Aspen buds also contain a high amount of flavonoids, while the leaves and twigs contain insoluble fiber.

Salicin is metabolized by the liver into salicylic acid, the active ingredient in aspirin.

Herbs like cayenne and devil's claw also possess analgesic and anti-inflammatory properties.

Aspen Cautions

Those with an allergy to aspirin must avoid aspen preparations.

How to Consume Aspen

The bark of the aspen tree is used medicinally thanks to its salicin content, similar to willow. On occasion, the leaves may be combined with the bark. Aspen preparations are homemade, so they are not standardized.

Remedies

Main preparations: Decoctions, ointment

  • Decoctions. An aspen decoction can be brewed from about one to four grams of bark steeped in a cup of water. Because the bark is tougher than leaves or flowers, it will need to steep longer than an infusion.

  • Ointment. Aspen ointment is used for topical applications, such as on sunburns. The tree's buds are often added to the ointment to thicken it.

Buying

Quick Facts (Buying)
  • Where to buySpecialized health stores, Online herb stores

Aspen is available to buy in its original tree form at any local nursery or through online carriers. Aspen bark extract is popularly used in skin care products and can be found in cosmetic stores. Though uncommon, aspen extract, ointment, and tablets are also available and can be purchased in specialty nutrition shops and online retailers.

Growing

Quick Facts (Growing)
  • Life cyclePerennial
  • Harvested partsBark
  • Light requirementsFull sun
  • Growing habitatCool temperate regions

Growing aspens can be tricky because their root system requires a lot of room to grow and branch out.

Growing Guidelines

  • Aspens can't be propagated by cuttings and they rather spread laterally through suckers, which become dense and invade large areas. Open spaces are ideal for aspen groves.

  • Aspens require plenty of sunlight.

  • Aspen prefers damp and moist areas, as well as cool, temperate climates.

  • They adapt to many different environments and altitudes, but are sensitive to extreme heat.

Additional Information

Quick Facts (Additional Information)
  • Other usesPaper, Cosmetics, Timber

Plant Biology

Aspen is a deciduous tree that can grow up to 40 - 100 feet (12 - 30 m) in height. Aspen groves are unique because they consist of one huge organism, not individual trees. Quaking aspens can be found in nearly every state of the United States and most Canadian provinces.

Aspens are characterized by their smooth, white bark with black scars where lower branches have naturally self-pruned. Leaves are small and oval, almost heart-shaped, and are attached by long stalks called petioles. The long petioles allow the leaves to quiver in the wind, giving them their common name. The leaves change from green to golden and sometimes bright red in the fall.

  • Classification

    Aspen (Populus tremuloides), is a member of the Salicaceae or willow family, which it is thought to comprise 350-500 species distributed across two genera of great economical importance: Populus (poplars) and Salix (willows). The classification of these species is quite difficult for botanists due to their many similarities, and even their place within the Salicaceae family has been questioned.

  • Related Species and Varieties of Aspen

    The genus Populus or poplar comprises around 40 species of deciduous trees around the world; however, two main species are widely distributed across North America: balsam poplar (P. balsamifera) and trembling aspen (P. tremuloides). Other important species in the genus are P. deltoides and P. trichocarpa.

    According to the United States Department of Agriculture (USDA), extensive genetic and morphological variations exist within the range of the aspen tree. A number of subspecies and varieties have been described, but none are currently recognized.

Historical Information

Poplar trees have been known in Europe since the dawn of human civilization, when they grew naturally along rivers and open spaces not meant for agricultural development.

Likewise, Native Americans have been using aspen trees for shelter and medicinal purposes long before the arrival of Europeans into the New World. The Chippewa would chew the aspen bark or root and apply it as a poultice in order to heal wounds and prevent infections.

Toward the end of the 17th century, "Canadian" poplars were imported from France and propagated in the vicinity of Turin, Italy, where their rapid growth fascinated the local plant-breeders. It wasn't until the 19th century though, that American poplars really conquered the rest of the world, since paper manufacturers began to use aspen wood to produce pulp.

During the first decade of the 19th century the covers of school books were labeled as made of "Canadian poplars."

The first attempt to use the active compounds of a willow bark to successfully treat malaria was carried out by Edward Stone in 1763. Since then, the analgesic, anti-inflammatory salicilates of both Populus and Salix species have been widely used by the pharmaceutical industry. Even today, the aspirin-like effect of the aspen bark, without the usual stomach irritation caused by commercial drugs, is still valued by herbalists and pharmaceutical companies as well. 

Economic Data

Aspens are widely used in the timber industry to make pallets, crates, paper, pulpwood, and playgrounds. It is highly valuable for shipping purposes (i.e., crates, boxes, packing) because of its light weight and strength. It is widely preferred for making playgrounds because it does not splinter easily.

In 2012, global industrial aspen production amounted to 1.7 billion cubic meters, with the United States and Canada leading production. The same year, the U.S. was by far the largest producer in the world, with 321 million cubic meters.

Popular Beliefs

According to Greek mythology, the poplar or aspen three was sacred to Hercules because when bitten by a snake he found a remedy for the poison in its leaves.

In Sicily it is customary on solstice eve to cut down the tallest poplar and drag it through the village while shouting and beating a drum, while a crowd dances and sings around the tree.

During the Victorian era aspen trees symbolized lamentation and fear.

Other Uses

Aspen trees are mainly used in the timber industry. Aspen wood is lightweight and strong, so it is popular for making shipping boxes, plywood, and furniture.

The benzoic acid in aspen leaves is used to preserve foods and manufacture dyes, while aspen buds contain p-hydroxybenzoic acid, which is also used in the production of dyes and fungicides. Additionally, the catechol from the bark has commercial applications in photography and dyeing. Aspen bark extract is also an ingredient in pharmaceutical products and cosmetics.

Other uses include animal bedding, fence posts, siding, shavings to pack produce, and paper. Its strong pulp is inexpensive, easy to peel, and it bleaches well, so it is a popular choice for paper production.

Bibliography

  • Encyclopedia of Herbal Medicine, p. 255
  • Medicinal Plants of the World, p. 252
  • FAOSTAT, Aspen report
  • The Herbal Handbook
  • U.S. National Park Service Plant Guides, Quaking Aspen
  • Dan Medicinhist Arbog, From willow bark to acetylsalicylic acid, 2009
  • Poplars and Willows: Trees for Society and the Environment, p. 580
  • Central Yukon Species Inventory Project (CYSIP), Salicaceae : Willow Family | Populus tremuloides : Trembling Aspen
  • Medicinal Herb Handbook, pp. 6, 28
  • Poplars and Willows in Wood Production and Land Use, p. 8
  • San Francisco State University Department of Geography and Environment, Biogeography of Quaking Aspen (Populus tremuloides)