Ulmus rubra / Olm

Tot zo’n eeuw geleden was de iep beeldbepalend in het Nederlandse en Vlaamse landschap. Miljoenen iepen groeiden er langs wegen en dijken, rond boerderijen, op forten en stadswallen en in dorpen en steden: sinds eeuwen is de iep stadsboom nummer één. Het gebruik door de mens gaat zelfs duizenden jaren terug. De statige bomen vervulden een belangrijke rol in legenden en volksgebruiken, want het hout was in trek voor bogen, voor houtsnijwerk en scheepsbouw, en zelfs enige tijd voor de carrosserieën van auto’s. Van de iepenbast maakte men touw. Blad, twijgen en bast speelden een grote rol als veevoer, en iepen waren lang onmisbaar in de wijnbouw. Maar toen kwam de iepenziekte, die zich vanuit de Lage Landen over vier continenten uitbreidde en de soort nagenoeg uit het landschap wegvaagde.

North American Indians and early settlers used the inner bark of the slippery elm not only to build canoes, shelter, and baskets, but as a poultice or as a soothing drink. 2 , 4 , 5 Upon contact with water, the inner bark, collected in spring, yields a thick mucilage or demulcent that was used as an ointment or salve to treat urinary tract inflammation and was applied topically for cold sores and boils. A decoction of the leaves was used as a poultice to remove discoloration around blackened or bruised eyes. Surgeons during the American Revolution treated gun-shot wounds in this manner. 3 Early settlers boiled bear fat with the bark to prevent rancidity. 1 , 4 Late in the 19th century, a preparation of elm mucilage was officially recognized in the United States Pharmacopoeia. 6


Slippery elm contains carbohydrates including starches with mucilage being the major constituent. It contains hexoses, pentoses, and polyuronides. 2 , 7 The plant also has phytosterols, sesquiterpenes, calcium oxalate, cholesterol, and tannins (3% to 6.5%) as constituents. 2 , 4 , 7 Isolation and structure of a cyanidanol glycoside has been reported from related species U. americana . 8

Slippery Elm Uses and Pharmacology

Slippery elm prepared as a poultice coats and protects irritated tissues such as skin or intestinal membranes. The powdered bark has been used in this manner for local application to treat gout, rheumatism, cold sores, wounds, abscesses, ulcers, and toothaches. 4 , 7 It has also been known to “draw out” toxins, boils, splinters, or other irritants. 2

Powdered bark is incorporated into lozenges to provide demulcent action (soothing to mucous membranes) in the treatment of throat irritation. 9 It is also used for its emollient and antitussive actions, to treat bronchitis and other lung afflictions, and to relieve thirst. 1 , 2 , 3 , 5 , 7

When slippery elm preparations are taken internally, they cause reflex stimulation of nerve endings in the GI tract, leading to mucus secretion. 2 This may be the reason they are effective for protection against stomach ulcers, colitis, diverticulitis, gut inflammation, and acidity. Slippery elm is also useful for diarrhea, constipation, hemorrhoids, irritable bowel syndrome, and to expel tapeworms. It also has been used to treat cystitis and urinary inflammations. 2 , 3 , 4 , 7

The plant is also used as a lubricant to ease labor, 3 , 4 as a source of nutrition for convalescence or baby food preparations, 2 and for its activity against herpes and syphilis. 4 The tannins present are known to possess astringent actions. 7


1. Hocking G. A Dictionary of Natural Products. Medford, NJ: Plexus Publishing Inc. 1997;826-27.

2. Chevallier A. Encyclopedia of Medicinal Plants. New York, NY: DK Publishing. 1996;144.

3. Low T, et al, eds. Magic and Medicine of Plants. Surry Hils, NSW:Reader's Digest Assoc. Inc. 1994;385.

4. Duke J. CRC Handbook or Medicinal Herbs. Boca Raton, FL: CRC Press, Inc. 1989;495-96.

5. Tyler V. Herbs of Choice, The Therapeutic Use of Phytomedicinals. Binghamton, NY: Pharmaceutical Products Press. 1994;93,94.

6. Lewis W, Elvin-Lewis MPF. Medical Botany. New York, NY: J. Wiley and Sons, 1977.

7. Newall C, et al. Herbal Medicines. London, England: Pharmaceutical Press. 1996;248.

8. Langhammer I. Isolation and structure of a rarely occurring cyanidanol glycoside from Cortex betulae . Planta Medica 1983 Nov;49:181-82.

9. Morton J. Major Medicinal Plants. Springfield, IL: C.C. Thomas, 1977.

10. Rotblatt M, Ziment I. Evidence-Based Herbal Medicine . Philadelphia, PA: Hanley & Belfus; 2002.


Slippery elm bark is a widely used herbal remedy and is considered to be one of the most valuable of remedies in herbal practice. In particular, it is a gentle and effective remedy for irritated states of the mucous membranes of the chest, urinary tubules, stomach and intestines. The inner bark contains large quantities of a sticky slime that can be dried to a powder or made into a liquid. The inner bark is harvested in the spring from the main trunk and from larger branches, it is then dried and powdered for use as required. Ten year old bark is said to be best. Fine grades of the powder are best for internal use, coarse grades are better suited to poultices. The plant is also part of a North American formula called essiac which is a popular treatment for cancer. Its effectiveness has never been reliably proven or disproven since controlled studies have not been carried out. The other herbs included in the formula are Arctium lappa, Rumex acetosella and Rheum palmatum. The inner bark is demulcent, diuretic, emollient, expectorant, nutritive. It has a soothing and healing effect on all parts of the body that it comes into contact with and is used in the treatment of sore throats, indigestion, digestive irritation, stomach ulcers etc. It used to be frequently used as a food that was a nutritive tonic for the old, young and convalescents. It was also applied externally to fresh wounds, burns and scalds. The bark has been used as an antioxidant to prevent fats going rancid. The whole bark, including the outer bark, has been used as a mechanical irritant to abort foetuses. Its use became so widespread that it is now banned in several countries.