In 1999, the graduate students in the Sustainable Development and Conservation Biology Program of the University of Maryland investigated the status of four medicinal plants native to the United States, with a view toward assessing whether they should be proposed for listing under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The results of their study are presented below. The U.S. Fish and Wildlife Service does not officially endorse the opinions or ideas expressed herein, or guarantee the validity of the information provided.
The Problem Solving Course
Sustainable Development and Conservation Biology
University of Maryland
December 14, 1999
Cimicifuga racemosa (Black Cohosh)
Ligusticum porteri (Osha)
Serenoa repens (Saw Palmetto)
Ulmus rubra (Slippery Elm)
Black cohosh (Cimicifuga racemosa) is a small, woodland plant with a large range throughout the United States. Black cohosh is native to the eastern woodlands of North America and ranges from southern Canada south to Georgia, across to Arkansas and up to Wisconsin. It is more abundant in its southern range. The Flora of North America Association claims that populations in Maine and Vermont were probably planted by humans and do not occur there naturally. Both United Plant Savers and the National Center for the Preservation of Medicinal Herbs list C. racemosa as "at risk". In Tennessee, it is listed as a threatened species (Ramsey, 1981).
The root of this plant is wildcrafted throughout its range. Populations in some states, such as Illinois, have declined or disappeared due to heavy wildcrafting (Mohlenbrock 1981, p. 125). However, it can be cultivated and many herbalists are now cultivating this species for root collection (Suggs, personal communication). Paul Strauss, of United Plant Savers, has been cultivating the plant for a few years, and suggests that unless more sellers begin cultivating the plant, populations will be severely affected (Strauss, personal communication). Michael McGuffin, President of the American Herbal Products Association, believes that cultivation of black cohosh will not be a great challenge, as it has flexible life cycle requirements and can withstand varying levels of light and shade (McGuffin, personal communication). Feather Jones, of the Rocky Mountain Herbal Coalition, stated that, unless cultivation of black cohosh increases, "it won't be long until the U.S. Fish and Wildlife Service has to restrain harvesting" (Jones, personal communication). She also indicates that more growers are expected to begin cultivating the plant in the next two to three years.
Black cohosh has become a very popular herbal remedy in Europe and the United States. It is typically used in treating menopausal symptoms, especially "hot flashes" (Cech, 1999). Since 1995, it has become one of the most important plants in the therapy of gynecological diseases. Flavones, known to be pharmacologically active, have been isolated from C. racemosa rhizomes (Struck et al., 1997.) Already popular in Europe where most of the harvest is still shipped, it is expected to see increased use in the U.S. as a greater number of women approach menopause. IRI cited black cohosh as one of the fastest "growing herbal products for 1998, with a 511% increase over 1997," but it is not yet one of the 12 top-selling herbals (Breevort, 1998). Black cohosh could become one of the top 10 selling herbs in the near future (http://www.ncpmh.org/blacoh.html). In addition to its popularity among local herbalists and small businesses, large pharmaceutical companies have added this herb to their offerings. Bayer, the parent company of One-a-Day vitamins, recently included black cohosh in its product line.
At present, there is no large-scale cultivation of black cohosh; nearly 100% of the supply comes from wildcrafted sources. Without cultivation, this herb will soon be wildcrafted to the point that it can no longer meet the needs of the industry. Growing black cohosh from seed is harder, and seeds are not readily available (http://www.ncpmh.org/blacoh.html). With regard to trade, most C. racemosa is exported to Germany (Cech, McKowan, pers. comm.). Furthermore, demand is significant with the largest pharmaceutical company that produces "Remifemin" describing their demand for tons of the rhizome annually (McKeown 1999).
A recent TRAFFIC assessment of the trade in herbal medicines found a significant increase in demand for C. racemosa (Robbins 1999). While trade can be described as "medium, medium/large or large" both populations of black cohosh and the species as a whole have declined in the past ten years (Robbins, 1999). TRAFFIC therefore named black cohosh as a priority for further study on U.S. Forest Service lands.
This species does qualify for CITES Appendix II listing. Black cohosh is in high demand both domestically and internationally, and very few people are cultivating it. It is not easy to grow, but growing techniques are improving, and more cultivators are becoming interested as the market for this plant expands. Politically, it may be difficult to pass a proposal for CITES Appendix II listing for black cohosh. Regardless of whether a proposal is written, this species deserves conservation attention.
Osha is the common name attributed to species in the genus Ligusticum that are collected for medicinal use. Apparently, species other than L. porteri in this genus are also collected. Osha is a perennial herb that grows in moist fertile ground, in upland meadows and ravines throughout its range (Plants for a Future). The range for this species spans from the Rocky Mountains south through Mexico to Chihuahua. The entire root is harvested in the wild. According to Trish Flaster of Botanical Liasons, osha is not cultivated; therefore all plant material is taken from the wild. There are individuals currently working out propagation protocols, but the information is not yet available and they have not been successful to date.
All Ligusticum species are included on the United Plant Savers "At Risk" list. Robbins (1999) classified populations as in decline over the past ten years. Others are in agreement, including Richo Cech, especially with regard to local populations that can be wiped out by one or more collectors in a given area. Teresa Prendusi (Forest Service Region 4 botanist) mentioned that L porteri is a member of a community called "Tall Forb Type" which essentially is a climax high elevation meadow characterized by tall forbs and deep soils. This is one of the region 4's highest priority habitats due to destruction from sheep grazing. She mentioned that L. porteri is late successional in that community and thus is not only threatened from the collection aspect but also from the loss of habitat. Cech added that in addition to pressures on this species by wildcrafters, there might be local population decline as a result of habitat destruction for residential and commercial development in prime habitat regions
In Montana, L. porteri only exists in Carbon County (Dorn, Vascular Plants of Montana, 1984). According to Steve Shelly - Region 1(Montana, Northern South Dakota, North Dakota, and Northern Idaho) botanist USFS, a moratorium for collection of any Ligusticum species passed last spring. This state law only pertains to state-owned lands. The USFS subsequently issued a Regional policy that recommends no issuance of collecting permits on USFS lands. The USFS policy extends throughout Region 1. However, while the species is rare in the state of Montana, it is not officially "endangered" (Klein, personal comm.). L. porteri is much more common in Colorado and south through New Mexico.
According to Theresa Prendusi (Region 4 Botanist), due to the fact that Idaho is shared by Region 1 and 4, the moratorium on collection of L. porteri for Region 1 (described above) was also adopted by Region 4 (Southern Idaho, Western Wyoming, Nevada, and Utah). This was primarily set up for prevention of collection of Echinacea, but all species listed on the Region 1 moratorium, including L. porteri, may not be collected as no permits will be issued. She suggested that much of the Mexican population of L. porteri has been depleted thus increasing harvest pressures in the U.S. No studies that she knows of are being conducted at this time.
The Utah Natural Heritage Program has listed L. porteri in their "Endemic and Rare Plants of Utah" but under the category of Taxonomic Problems. It appears to be currently widespread but locally rare. The New Mexico Rare Plant Technical Council Meeting on 28 March, 1998 identified L. porteri as a plant that may not be at present biologically rare but possibly in need of management because of collection. They indirectly refer to United Plant Savers as a reference. They are in the process now of putting together rare plant technical reports for management of the species identified (http://biology00l.unm.edu/~chelo/min.htm).
The historical status of this plant can be highlighted in several key publications. In 1975, Stanley Welsh published "Endangered, Threatened, Extinct, Endemic, and Rare or Restricted Utah Vascular Plants" in the Great Basin Naturalist (v35, n4) that listed L. porteri as endemic, rare, and local possibly threatened. In 1978, the Smithsonian and World Wildlife Fund published "Endangered and Threatened Plants of the U.S." listing L. porteri as threatened. It appears that the Welsh article was the only reference for this listing. Additionally, in 1985, Welsh wrote a follow-up article "Utah's Rare Plants Revisited" in which L. porteri was completely omitted from the article - assumedly meaning that the plant was no longer even under consideration (GBN, v45, n2). Finally, in 1986, IUCN published Plants in Danger, which led to the listing of L. porteri on the IUCN list. Again, the basis of the listing seems to be Welsh's article from 1975.
According to Michael McGuffin, President of the American Herbal Products Association, with regard to trade, there may be a small demand nation-wide, but regionally, the species is in higher demand in the southwest United States. However, there is some evidence shared by Richo Cech that the demand for and export of this plant in Mexico is high as local populations in Mexico are also in decline. According to Robbins (1999) reported trade ranges from "medium, medium/large, or large". Frontier Herbs, a leading U.S. herbal company reported that the annual usage of whole osha root is 500 dry pounds, but it is not listed on their top selling list of the top 28 and top 100 best sellers.
Recommendations for this species is that there may not be enough information to warrant listing as a potential candidate to CITES, but the writing of a proposal should be considered if there is political support. However, conservation attention is probably needed regardless. This species may become threatened in local populations across some regions. Furthermore, demand is growing while cultivation methods have not yet been perfected. Since the entire root is usually taken by wildcrafters, this exacerbates the threat to population stability. In ranking the four plants in this study, L. porteri should receive priority conservation attention.
Saw Palmetto (Serenoa repens) is abundant throughout Florida and South Carolina except in wetlands. It is an evergreen shrub often growing in low pine woods, savannas, and thickets, as well as on coastal sand dunes (Plants for a Future). According to Anglin, from USFS Region 8, the species re-sprouts and flowers prolifically after prescribed fires, which is a tool used extensively throughout Florida. Both the federal and state governments with jurisdiction over public natural areas use controlled burns to manage the landscape. Additionally, ranchers and other private landowners have been known to burn properties to retain native flora for pasture and eradicate undesirable plants.
The berries of S. repens are collected for medicinal use. The most popular use for this species is for the treatment and prevention of urinary tract problems and for reducing enlarged prostate (Braechman et al., 1997). It has also been cited as an aphrodisiac and the leaves are harvested for weaving baskets (Plants for a Future). Currently, this species is not cultivated and all plant material used in the industry comes from the wild. However the plant has the capability of being cultivated as an agricultural crop.
The US Forest Service holds one and one quarter million acres of land in Florida and regulates the collection of S. repens berries. Ann Lugbill with the Seminole District of the US Forest Service, reported some collection statistics based on permits issued in 1999. The district has recently revised its permitting policy due to increased demand for berries and an increased capacity for one permit holder to collect large amounts of plant material in one day. For example, the original policy stipulated a minimum permit of $25.00/ 500 lbs. with a permit length of 15 days. Three permits were issued with these regulations. After a crew of many individuals capable of picking 500 pounds of berries in one day arrived, the policy was revised. The revised policy stipulated four scenarios. First, with a maximum of 3 pickers, minimum permit of $100/ 2,000 lbs. in 5 days. The other categories follow: maximum of seven pickers, minimum permit of $200/4,000 lbs. in 5 days, maximum of 11 pickers, minimum permit of $300/6,000 lbs. in 5 days or maximum of 15 pickers, minimum permit of $400/8,000 lbs., in 5 days. The forest district issued three permits of the 3 pickers variety. In total they reported collection of 7,500 lbs. of berries, from 6 permits totaling $375.
Many experts in the field of wildcrafting, medicinal plants, herbalism, and others from the industry summarized that S. repens is marginally affected by collection for medicinal use. In general the plant is a major constituent of pine regions throughout the southeastern U.S.. It has even been referred to as a "weed" in some instances. Even when burned S. repens can return to its previous abundance within one year (Schmalzer and Hinkle, 1992). Additionally, the berries are collected which pose a minimal threat to individual mortality. At best, the collection of berries may have negative impacts on wildlife foraging success, as it is a favorite food of bears and other fauna in its native range.
Regardless of these opinions, the trade in S. repens is growing. A report published in Herbal Gram (Breevort, 1998) documented growth in U.S. sales of 158%. Europe is a major source of market demand for these plants, but currently a source for quantitative demand and sales to Europe has not been identified. In general terms, however, the species can be confirmed to be in trade both domestically and internationally. Chris Robbins, of TRAFFIC North America, is preparing a more extensive report on the trade of S. repens and will share his findings when his project is completed. Frontier Herbs, a leading U.S. herbal company reported that the annual usage of saw palmetto berries totals 4100 dry pounds, but this species is not listed on their list of the top 28 and top 100 best sellers.
Recommendation for this species is that it not be a candidate for proposal for CITES Appendix II listing. Although demand is large and growing, there have been noted no negative impacts to the wild populations. In fact, agents such as disturbance actually enhance population numbers and the harvesting of berries poses little consequence to mortality.
Slippery elm (Ulmus rubra) is a native, medium-sized, deciduous tree reaching 60 to 70 feet (18-21 m) on average sites and 135 feet (41 m) on the best sites. This species is a water-loving tree, grows best on moist, rich soils, and lowers slopes, stream banks, river terraces and bottomlands (Missouri Dept. of Conservation). U. rubra is a common tree species throughout temperate regions of North America. It has been described as a "successional species" as it invades abandoned old fields, savannas, woodland edges, and open riparian areas. This species may be cultivated, however presently it is not being raised in agriculture. This species is abundant and increasing with disturbance and abandonment of farmland (University of Kentucky).
The flowers open before the leaves, from February to May, depending on weather and location. Seeds ripen from April to June and are dispersed by wind and water as soon as they are ripe. Dispersal is by gravity and wind (Cooley et al., 1990; George et al., 1989). Seedlings become established under a wide variety of conditions. Mineral soil seedbeds are best, but seeds germinate and survive in forest litter or among herbaceous plants (Cooley et al., 1990). Slippery elm sprouts readily from the stump or root crown. Rhizomes can also produce seedlings.
Threats to this species include its vulnerability to Dutch elm disease; however, it may be more resistant to the fungus than other congenerics such as U. americana (University of Kentucky). It is also susceptible to elm yellow or elm phloem necrosis. Up to 30% of U. rubra trees in one region have died from Dutch elm disease (Strauss, personal communication).
The demand for this species is significant, both domestically and internationally (Duke). The inner bark of the tree contains a mucilagenous substance that aids in relieving sore throats and congestion (Cech). It has received approval by the Federal Drug Administration as an over the counter (OTC) drug ingredient (Breevort, 1998).
Very few suppliers are cultivating slippery elm—instead, it is predominantly wildcrafted. The harvesting of U. rubra may have a significant impact on individual trees as the inside of the bark is scraped and used for medicinal purposes. If done properly, this will not harm the tree. Paul Strauss, one of few growers who are cultivating the tree, is skeptical that many people are harvesting the bark properly (Strauss, personal communication).
A recent TRAFFIC report on trade in medicinal plants finds that trade in this plant is "medium, medium/large or large." Demand has increased in the past ten years and both populations of and the species as a whole have been in decline in the past ten years (Robbins 1999). Frontier Herbs, a leading U.S. herbal company, states that they sell approximately 11,000 dry pounds of slippery elm inner bark, 8000 of which is powder. This item is number eight on Frontier's top 28 best selling list, and number 69 on their top 100 best selling herbs and spices list (Werning, personal communication).
Slippery elm certainly has become more popular among U.S. buyers. If the bark is harvested sustainably, populations should not be seriously affected. However, it is difficult to determine the extent to which this type of harvest is occurring. In addition, Dutch elm disease may pose a threat to Ulmus rubra. However, until the spread of the disease has been documented, it will be difficult to assess the magnitude of the threat.
We do not recommend proposing CITES Appendix II listing at this point, but do recommend watching population trends in U. rubra, and getting information out to growers and harvesters about proper harvesting techniques.
Guy (USFS Region 8, FL) telephone interview with Kelly McConnell October 1999.
Bayer pharmaceuticals website. www.bayer.com.
Braeckman, J. Bruhwyler, K Vandekerckhove and J. Geczy. Efficacy and safety of the extract of Serenoa repens in the treatment of benign prostatic hyperplasia: therapeutic equivalence between twice and once daily dosage forms. Phytotheraphy Research 11, 1997.
Breevort, D. The booming U.S. Botanical Market: a new overview. Herbal Gram, 1998.
Cech, Richo, email to Laurie Duker on October 8, 1999.
Cech, Richo. United Plant Savers board member and herbalist. www.chatlink.com/~herbseed/slip.html
Cech, Richo. "Black Cohosh, Conqueror of Moods." UpS Newsletter, Summer 1999.
Cooley et al., 1990.
Duke, Jim (Botanical Consultant Herbal Vineyard, Inc), email to Natalie Bailey October 7, 1999.
Flaster, Trish (Botanical Liasons) email to Kelly McConnell on October 7, 1999.
Flora of North America website. www.fna.org/Libraries/plib/WWW/Magnollidae/T40009054.html.
George et al., 1989.
Herb Research Foundation (www.HRF.org)
Jones, Feather. Rocky Mountain Herbal Coalition. Telephone call with Natalie Bailey, October 18, 1999.
Klein, Robyn (Herbalist) email to Kelly McConnell on October 6,9,11 1999.
Lugbill, Ann (Seminole National Forest, FL) email to Kelly McConnell October 5, 1999.
McGuffin, Michael. Executive Director of the American Herbal Products Association. Telephone conversation with Natalie Bailey, October 11, 1999.
McKeown, Kathy (PhD, University of North Carolina) email to Kelly McConnell on October 12, 1999.
Missouri Department of Conservation website: www.conservation.state.mo.us
Mohlenbrock 1981. p. 125
National Center for the Preservation of Medicinal Herbs website: www.ncpmh.org.
Plants for a Future Database (www.PFAF.org).
Prendusi, Theresa (USFS Region 4) interview with Gary Dodge in October 1999.
Ramsey, G.W. The occurrence of Cimicifuga racemosa Kearney in the interior low plateaus province of Tennessee. Castanea: Journal of the Southern Appalachian Botanical Club. Volume 46, No. 2, 1981.
Robbins, Christopher (TRAFFIC North America). Medicine from U.S. Wildlands: An assessment of native plant species harvested in the United States for medicinal use and trade and evaluation of the conservation and management implications. Prepared for USDA Forest Service and The Nature Conservancy. July 1999.
Schmalzer, P.A. and C.R Hinkle. Recovery of oak-saw palmetto scrub after fire. Castanea. 57(3), 1992.
Shelley, Steve (USFS Region 1) interview with Gary Dodge in October 1999.
Strauss, Paul. Manager of United Plant Savers botanical sanctuary. Telephone conversation with Natalie Bailey. October 12, 1999.
Struck, D., M. Tegtmeier, and G. Harnischfeger. Flavones in extracts of Cimicifuga racemosa. Planta Medica 63, 1997.
Suggs, Robin, email to Kelly McConnell an October 6, 1999.
United Plant Savers (www.plantsavers.org).
University of Kentucky. Slippery elm, Ulmus rubra website. September 30, 1999. www.quercus.ca.uky.edu/treeweb/species/ulrubrl htm.
Welsh, Stanley. "Endangered, Threatened, Extinct, Endemic, and Rare or Restricted Utah Vascular Plants." Great Basin Naturalist. v35, n4, 1975.
Werning, Stacy (Frontier Herbal Co.) email to Kelly McConnell on October 24, 1999.
Widrlechner, Mark (USDA-ARS Horticulturist, Iowa State University) email to Kelly McConnell on October 6,1999.