For the past few years, officials at the Daniel Boone National Forest in Kentucky have received complaints and discovered the girdled remains of slippery elm trees (Ulmus rubra, Ulmaceae syn. U. fulva) illegally stripped of their bark by poachers selling to the herbal market (B. Bishop, oral communication, January 23, 2007). Such thieves are elusive, but US Forest Service officers were able to apprehend several offenders in the summer of 2006.( n1) Forest officials are working diligently to prevent further stripping of slippery elms, which appear to be joining the ranks of American ginseng (Panax quinquefolius, Araliaceae) root, goldenseal (Hydrastis canadensis, Ranunculaceae) root, and other medicinal plants as common victims of illegal harvesting.

The slippery elm is native to North America, with populations extending across much of central and eastern United States and into eastern Canada.( n2) Its inner bark is coated with a mucilaginous lining, for which the tree earned both its name and its long-standing reputation as a medicinal agent. The bark has demulcent, expectorant, emollient, diuretic, and nutritive properties,( n2) and it is one of the few herbal materials still classified by the. Food and Drug Administration (FDA) as an approved, nonprescription, over-the-counter (OTC) drug (See Table 1). Much of the slippery elm bark that reaches the herbal market is acquired through wild-harvesting, which is difficult to validate as legally or sustainably obtained.

Barry Bishop, a law enforcement officer with the US Forest Service, said he began to notice illegally stripped slippery elms in the 706,000-acre Daniel Boone National Forest in 2003 (B. Bishop, oral communication, January 23, 2007). Officials at the forest are aware of around 60 slippery elm trees that have been stripped of their bark over the past few years. Law enforcement officers, however, were unable to catch anyone in the act of perpetrating the crime until 2006. "We were finally at the right place at the right time," Bishop said.

Bishop apprehended 3 individuals who were illegally stripping slippery elm bark in June of 2006. Two of these illegal harvesters had been apprehended shortly beforehand by US Forest Service Special Agent Courtney McCrae for the same crime, and they told Bishop that they were stripping slippery elm bark in order to raise money to pay the ticket for their first offense. Special Agent McCrae apprehended 7 individuals for stealing slippery elm bark in June and August of 2006 (C. McCrae, oral communication, January 30, 2007).

The removal of timber or other forest products from public land, without special authorization, is prohibited under Title 36 of the Code of Federal Regulations.( n3) According to Bishop, federal statute dictates that anyone caught collecting or harvesting forest materials without a permit may be issued a fine ranging from $250 to $5,000 or arrested on charges for "theft or unlawful taking" or "criminal mischief in the first degree." Six of the individuals caught by McCrae were issued citations ranging from $75 to $275. The three individuals apprehended by Bishop pied guilty to criminal mischief in the second degree and were sentenced to serve 6 months of jail time in Leslie County, KY. "These people were jobless and had no base source of income, so the [state court] didn't seek [financial] restitution. There wouldn't have been a point," Bishop said.

"This activity is illegal and we're going to do what we can to stop it," said David Taylor, a US Forest Service botanist for the Daniel Boone National Forest (oral communication, January 23, 2007). "Law enforcement officials are keeping their ears to the ground. They're taking the reports seriously and checking them out."

Although it is possible to harvest the bark of slippery elm trees in a fashion that does not kill the tree--by removing only segments of bark at any given time--some harvesters girdle, and thereby kill, the tree. The inner layers of the bark provide for the flow of water and nutrients throughout the tree, and this process is cut off when the bark is completely or mostly removed.( n1) The tree literally starves to death.

Taylor noted that legal harvest of some materials within the forest is sanctioned when the harvester obtains the appropriate permits. "We do provide permits for many botanicals, such as ginseng or black cohosh," he said. These permits enable visitors to collect or harvest a set amount of certain herbs or materials from the forest for personal use. "We don't issue permits for slippery elm bark because it leaves dead or half-dead trees standing, which can be dangerous." Taylor explained that the stripped trees are often more susceptible to diseases or fungi, which could spread to adjacent trees.

Taylor said he did not know if illegal stripping of slippery elms is as prevalent within other state or national forests. "I do know that poaching in general of herbaceous species is pretty high." Bishop, meanwhile, said he was aware of numerous complaints from private land owners regarding stripped slippery elms.

Slippery elm bark has been valued for its medicinal properties for centuries. Various Native American tribes, for instance, employed slippery elm bark as a medicine or food.( n4) It was utilized as a sore throat remedy by the Iroquois and Mohegan tribes; a laxative by the Omaha, Pawnee, and Dakota tribes; a dermatological aid by the Menominee, Meskwaki, and Potawatomi tribes; and a tuberculosis remedy by the Cherokee, Catawba, and Iroquois tribes--to name just a few (See Table 2).

The tree soon became a source of medicine and nutrition for Euro-American settlers as well. It has been reported that soldiers of the Revolutionary War in 1776 subsisted on a jelly created from slippery elm bark after losing their way and being deprived of resources for over a week, and German botanist Prince Maximilian wrote of the medicinal properties of slippery elm in 1832.( n2) The company Thayers Natural Remedies began producing and marketing slippery elm lozenges in 1847. According to John Gehr, Thayers' vice-president of sales and marketing, Thayers remains the only company that sells a lozenge containing enough slippery elm material (150 mg) for the botanical to serve as an active ingredient, based on the FDA's OTC standards (J. Gehr, oral communication, October 24, 2006).( n5) Gehr claims that Thayers currently uses approximately 10,000 pounds of dried slippery elm bark each year. According to the Tonnage Survey of Select North American Wild-Harvested Plants, 2004-2005, prepared by the American Herbal Products Association (AHPA), the 2005 aggregate harvest of slippery elm bark consisted of 203,984 pounds of dried wild-harvested bark, 1,731 pounds of dried cultivated bark, and 74 pounds of fresh wild-harvested bark.( n6) The 2004 harvest was much lower, with only 78,380 pounds of dried wild-harvested bark and 803 pounds of dried cultivated bark reported, but data from 20012003 show figures on the same level as 2005. Gehr said that, to his understanding, the vast majority of processed slippery elm bark is used as bulk material for supplements and products, primarily as a digestive aid.

Thayers purchases its slippery elm bark from third-party suppliers, who obtain the bark through wild-harvesting. "Unfortunately, there's no way for us to know with certainty what the source of the slippery elm is, because it's only wild-crafted," Gehr explained.(*)

Chuck Wanzer of Botanics Trading LLC, a company based in Blowing Rock, NC, which provides ethically wildcrafted and cultivated botanicals, noted that this is a common problem for buyers of wild-harvested plants and materials (C. Wanzer, oral communication, January 9, 2007). Even wildcrafters who obtain their plant materials legitimately often do not like to disclose the locations they used for harvesting, in some cases because they do not want other harvesters to find and infiltrate their sites. "It's a tradition, especially up in the mountains, to do wildcrafting as a way of life and for the secondary income," Wanzer stated. According to Wanzer, there are a few ethical herb companies growing slippery elm trees for sustainable use, but the practice is not particularly cost-effective. Slippery elm bark that is certified as organic and sustainably grown usually sells for $9 a pound while non-certified bark typically sells for $4 a pound, making slippery elm one of the more under-priced herbal materials on the market.

This low market value may be saving many slippery elms from illegal harvesting. "The illegal stripping of the inner bark of slippery elm trees is unconscionable, but it is not occurring widely in the southern Appalachia area yet, mostly because the price of slippery elm is too low," said Lynda LeMole, executive director of United Plant Savers (UPS), a nonprofit dedicated to preserving native medicinal plants (e-mail, October 17, 2006). "This is an area where high-priced medicinal plants like American ginseng and goldenseal are abundant, and people are very aware of plant theft."

Wanzer argued that wildcrafting does not pose the greatest threat to slippery elms. "Development and logging are taking out much more of these trees than wildcrafters," he said. "There is a problem with habitat depletion killing everything--slippery elms included." Furthermore, once forest areas are cleared, any replanting is usually done in pines and firs, as opposed to elms. Dutch elm disease has taken its toll on some populations of slippery elms as well.( n2)

The many threats facing slippery elms have placed the tree in a rather ambiguous situation. According to Wanzer, slippery elm populations may be threatened in certain areas, but the tree itself is not in any immediate jeopardy as a species. He noted that slippery elms grow across a wide stretch of the United States and that there are plenty of thriving elms throughout the country. Taylor echoed such sentiments: "It's not a terribly common tree, but it's not rare either," he said. Gehr noted that Thayers has not witnessed any significant changes in the availability or cost of slippery elm material in recent years, which could further indicate that the tree's populations are not seriously threatened.

Some organizations, however, are taking precautionary measures to preserve and strengthen slippery elm populations. The National Center for the Preservation of Medicinal Herbs, a nonprofit that researches ways to raise and replenish medicinal botanicals, has placed the slippery elm on its protection list,( n7) and UpS has similarly added the tree to the organization's "At Risk" list.( n8) UpS planted 500 young slippery elms in its botanical sanctuary in Meigs County, OH, in 1998 to both replenish slippery elms and to serve as a possible research site for experimenting with cures for Dutch elm disease and other diseases affecting elms, such as elm phloem necrosis (L. LeMole, e-mail, October 17, 2006). According to LeMole, approximately 90% of the planted elms are still thriving in the sanctuary. "One helpful aspect for slippery elm trees is that each tree casts out a tremendous amount of seed," said LeMole. "The trees begin producing seed at about 12-18 years of age. Since the wood of the slippery elm (also known as the red elm) is so hard, the trees contract the Dutch elm disease at about 12-18 years old. So it is a race--Can they produce seed before perishing from disease? Therefore, it is important to keep planting the trees and keep them going in the hope that a disease resistant strain will develop or that they can cross to produce a valuable variety that is disease resistant."

Forest officials at the Daniel Boone National Forest are similarly striving to maintain their slippery elm populations. Bishop said the US Forest Service is spreading information about forest regulations to ensure that people understand that stripping slippery elm bark on public land is illegal. The Forest Service has also asked that the public assist in reporting such illegal activities).( n1, n7)

"Every species out there plays some role in the environment --including slippery elms," said Taylor. According to Taylor, the illegal harvesting of any plant from the forest disrupts the natural environment and makes it difficult for forest officials to adequately assess plant populations and determine how various activities are influencing forest species. "The [US Forest Service] is a conservation organization. We want to be able to provide these resources down the road," he added.

(*) HerbalGram received the following comment from a reviewer of this article: "My company [Traditional Medicinals, Inc., Sebastopol, CA] uses nearly as much dried elm bark annually as Thayers, but for many years we have been obtaining it under organic certification rules for wild crops, which have some traceability and transparency requirements. We know where our organic wild elm bark is harvested. I have discussed the sustainable wild harvest management plan with the harvester, and he has invited us to the collection site in order to observe and document the harvest. So it is possible to know more about where your elm is coming from if you can justify paying the premium for organic certification" (J Brinckmann, e-mail, March 28, 2007).
Table 1. Selected Data from Government and Authoritative Sources on Elm Bark as an FDA-Approved Nonprescription (Over-the-Counter) Demulcent Drug Ingredient ELM BARK
Name of Category I(*) Active Ingredient

[Note: Slippery elm bark is referred by 3 common names in various compendia.]

• Code of Federal Regulations (CFR) Monograph: Elm bark (FDA, 1991).

• United States Pharmacopeia (USP) Monograph: Elm (USP, 2006).

• American Herbal Products Association's (AHPA) Standardized Common Name (SCN): Slippery elm (McGuffin et al., 2000).
Regulatory Status and Rulemaking History

• FDA Review Panel: The OTC Oral Cavity Drug Products Advisory Review Panel.

• FDA Report: Oral Health Care Report of FDA Panel.

• Drug Category: OTC Demulcent Active Ingredient.

• Advance Notice of Proposed Rulemaking: Category I*: 21 CFR §356.16(a) (FDA, 1982).

• Notice of Proposed Rulemaking: Category I: 21 CFR §356.18(a) (FDA, 1988).

• Proposed Rule: Category I: 21 CFR §365.18(a) (FDA, 1991). Final Rule: Pending (FDA, 2006a).

The botanical raw material complies with the qualitative and quantitative standards defined in the Elm monograph of the United States Pharmacopeia (Elm USP).

Elm USP: Elm is the dried inner bark of Ulmus rubra, Muhlenberg (Ulmus fulva, Michaux) (Fam. Ulmaceae). It contains not more than 2% of adhering outer bark (USP, 2006).
Statement of Identity

The labeling of products containing elm bark as the demulcent active ingredient includes the established name of the drug, if any, and identifies the product as an "oral demulcent" (FDA, 1991).
Purpose of the Active Ingredient

Demulcent: A bland, inert agent that soothes and relieves irritation of inflamed or abraded surfaces such as mucous membranes (FDA, 1991).

For temporary relief of minor discomfort and protection of irritated areas in sore mouth and sore throat (FDA, 1991).
Directions and Dosage

The product is 10 to 15% elm bark in a solid dosage form (FDA, 1991); e.g., incorporated in an agar or other water-soluble gum base in the form of a lozenge (FDA 1982).

Adults and children 2 years of age and older. Allow lozenge to dissolve slowly in the mouth. May be repeated every 2 hours as needed or as directed by a dentist or doctor. Children under 2 years of age: Consult a dentist or doctor (FDA, 1991).

Packaging requirements: Elm lozenge packages for retail sale are exempt from the tamper-evident packaging requirements of the finished pharmaceuticals current good manufacturing practices (cGMPs) for OTC human drug products (FDA, 1998).
Permitted Combinations with other Herbal Oral Health Care Active Ingredients

Elm bark and menthol (FDA, 1991).
Stop use and ask doctor or dentist

• if sore throat is severe,

• persists for more than 2 days,

• is accompanied or followed by fever, headache, rash, nausea, or vomiting, or if sore mouth symptoms do not improve in 7 days (FDA, 1991).

Sore throat warning: Severe or persistent sore throat or sore throat accompanied by high fever, headache, nausea, and vomiting may be serious. Consult physician promptly. Do not use more than 2 days or administer to children under 3 years of age unless directed by physician (FDA, 2006b).

If pregnant or breast-feeding, ask a health care professional before use. Keep out of reach of children.

(*) Category I refers to an FDA-approval for safety and efficacy of an active ingredient in a nonprescription (over-the-counter) drug.

Food and Drug Administration (FDA). 21 CFR Part 356--Oral Health Care Drug Products for Over-the-Counter Human Use; Establishment of a Monograph. Advance notice of proposed rulemaking. Federal Register. 25 May 1982;42(101):22760-22930.

Food and Drug Administration (FDA). Oral Health Care Drug Products for Over-the-Counter Human Use; Tentative Final Monograph. Notice of proposed rulemaking Federal Register. 27 January 1988;53(17):2436-2461.

Food and Drug Administration (FDA). Oral Health Care Drug Products for Over-the-Counter Human Use; Amendment to Tentative Final Monograph to Include OTC Relief of Oral Discomfort Drug Products. Notice of proposed rulemaking Federal Register. 24 September 1991;56(185):48302-48347.

Food and Drug Administration (FDA). 21 CFR Part 211--Tamper-Evident Packaging Requirements for Over-the-Counter Human Drug Products. Final Rule. Federal Register; 1998;63(213):59463-59471.

Food and Drug Administration (FDA). Over-The-Counter Human Drugs; Labeling Requirement. Final Rule: 21 CFR §201.66 Format and content requirements for over-the-counter (OTC) drug product labeling. Federal Register. 1999;64(51):13254-13303.

Food and Drug Administration (FDA). OTC Ingredient List. Rockville, MD: FDA. August 2006a.

Food and Drug Administration (FDA). 21 CFR §201.315 Over-the-counter drugs for minor sore throats; suggested warning. In: Code of Federal Regulations: Washington, DC: National Archives and Records Administration. 1 April 2006b.

McGuffin M, Kartesz JT, Leung AY, Tucker AO. American Herbal Products Association's Herbs of Commerce, 2nd Edition. Silver Spring, MD: American Herbal Products Association. 2000.

United States Pharmacopeial Convention. USP 29-NF 24. Rockville, MD: United States Pharmacopeial Convention. 2006.

Source: Adapted from Brinckmann J. Herbal Drugs: Monographs of the United States of America Code of Federal Regulations. Austin, TX: American Botanical Council. In press.
Table 2. Medicinal Use of Slippery Elm by Native Americans

Tribe Medicinal Use of Slippery Elm

Alabama Gynecological aid (bark)

Catawba Tuberculosis remedy (bark)

Cherokee Antidiarrheal (bark); Burn dressing
(bark); Cold remedy(*); Cough medicine(*);
Dermatological aid (bark);
Eye medicine (bark); Gastrointestinal
aid(*); Gynecological aid (bark);
Laxative(*); Respiratory aid(*); Throat
aid(*); Tuberculosis remedy(*)

Chipewa Throat aid (bark/root)

Creek Witchcraft medicine (bark)

Dakota Laxative (bark)

Iroquois Blood medicine(*); Emetic(*); Eye medicine
(bark); Gastrointestinal aid (bark);
Gynecological aid (bark);
Kidney aid (bark); Respiratory aid
(leaves); Stimulant(*); Throat aid
(bark); Tuberculosis remedy(*)

Kiowa Oral aid (bark)

Mahuna Orthopedic aid (bark)

Menominee Cathartic (bark); Dermatological aid

Meskwaki Dermatological aid (bark); Gynecological
aid (root)

Micmac Dermatological aid (bark); Pulmonary
aid (bark)

Mohegan Cough medicine (bark); Pulmonary aid
(bark); Throat aid (bark)

Ojibwa Dermatological aid (root); Gastrointestinal
aid(*); Hemostat (root); Throat aid
(bark); Venereal aid(*)

Omaha Laxative (bark)

Pawnee Laxative (bark)

Ponca Laxative (bark)

Potawatomi Dermatological aid (bark); Eye
medicine (bark); Throat aid

Winnebago Laxative (bark)

(*) Plant part used in remedy not specified

Source: Moerman D. Native American Ethnobotany.
Portland, OR: Timber Press; 1998.

PHOTO (COLOR): Slippery Elm Ulmus Rubra Illustration from The North American sylva, or, A description of the forest trees of the United States, Canada and Nova Scotia by François Andre Michaux (1770-1855) Courtesy at Missouri Botanical Garden

PHOTO (COLOR): Left top photo: Slippery Elm Ulmus rubra Photo © 2007 Steven J. Baskauf

PHOTO (COLOR): Left photo: Slippery Elm Ulmus rubra Photo © 2007 Steven Foster

PHOTO (COLOR): Above photo: Slippery Elm Ulmus rubra bark detail Photo ©2007 Steven J. Baskauf

PHOTO (COLOR): Bottom photo: The rust-colored buds are the source of Slippery Elm's species designation "rubra" meaning red. Slippery Elm Ulmus rubra Photo ©2007 Steven Foster

PHOTO (COLOR): Above photo: Slippery Elm Ulmus rubra branch and leaves. Photo ©2007 Steven J. Baskauf

PHOTO (COLOR): Left photo: The wafer-like fruits of Slippery Elm Ulmus rubra. Photo ©2007 Steven Foster

PHOTO (COLOR): Powdered Slippery Elm Ulmus rubra with pre-1850s Shaker label, and plate from George B. Emerson's A Report on the Trees and Shrubs Growing Naturally in the Forest of Massachusetts. 2nd ed. Boston: Little Brown, and Company, 1875. Photo ©2007 Steven Foster

(n1.) Theft of natural resources occurring on national forest lands [press release]. Winchester, KY: Daniel Boone National Forest; June 27, 2006.

(n2.) Strauss P. Slippery Elm. In: Gladstar R, Hirsch P, eds. Planting the Future. Rochester, VT: Healing Arts Press; 2000.

(n3.) Title 36. Code of Federal Regulations, Part 261.6(h).

(n4.) Moerman D. Native American Ethnobotany. Portland, OR: Timber Press; 1998.

(n5) Food and Drug Administration. Oral health care drug products for over-the-counter human use. 1991. Federal Register. 56:48342-48346.

(n6.) American Herbal Products Association. Tonnage Survey of Select North American Wild-Harvested Plants, 2004-2005. Silver Spring, MD: American Herbal Products Association; 2007.

(n7.) Jafari S. Trees stripped for medicinal bark for herbal market. Associated Press. July 15, 2006.

(n8.) UpS "At-Risk" & "To Watch" List. United Plant Savers Web site. Available at: Accessed October 5, 2006.


By Courtney Cavaliere

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