CHAPTER 35 APPENDIX Native American Medicinal Plants
Native American peoples developed a sophisticated plant-based medical system in the millennia before the arrival of Europeans. Many of the plants that these people used are familiar medicinal species and have taken a role in contemporary medicine. For example, Echinacea is well known in Europe and increasingly well known in North America as a treatment for colds and particularly as an “immune system stimulant.” The cone flowers, Native American species, were used more than 100 ways by a dozen midwestern tribes (e.g., Blackfoot, Cheyenne, Dakota, Omaha, Pawnee, Paiute) to treat a variety of diseases and conditions, including headaches, burns, and toothaches. The Winnebago used Echinacea in an interesting way: fire handlers used the plant to make themselves insensitive to hot coals that they put in their mouths.
Another very interesting plant—Podophyllum peltatum, the mayapple—is less well known to the public but is probably more important medically than Echinacea. Native Americans used the plant in many ways, but the most common use was as a laxative or purgative, which was a common use of the plant in early American medicine as well. For many years, podophyllum resin has been a standard treatment for venereal warts. Also, etoposide (VePesid), a semisynthetic derivative of podophyllotoxin, another mayapple constituent, is an effective treatment for refractory testicular tumors and for small cell lung cancer.
Plants used by Native Americans as medicinal species can also be dangerous. This danger is apparent with toxic species such as Datura meteloides (jimsonweed) and Heracleum maximum (cow parsnip), but others are less obviously dangerous. A classic case is ephedrine, derived from several species of the genus Ephedra, notably E. sinica. The American species, E. viridis, contains less ephedrine than the Asian species. It was used by many Native American groups for the treatment of internal illnesses. It has a long use in the American Southwest as a stimulating drink known as “teamster’s tea” or “Mormon tea,” and the drug and various synthetic variations (particularly pseudoephedrine) is a useful decongestant. In the recent past, herbal drug companies made capsules containing from 7 to more than 40 mg of ephedrine, along with other Ephedra alkaloids, and sold them under such names as “Herbal Ecstasy,” “Ultimate Xphoria,” and “Cloud 9.” These drugs presumably mimic the action of the street drug MDMA (4-methyl-2,5-dimethoxyamphetamine)—illegal in the United States—which produces euphoria; the street name of the drug is “Ecstasy.” A number of people taking six to eight of these “herbal highs” have died of heart attack, stroke, and various types of seizures.1 Just because a drug is “natural” does not mean it is safe.
There are many such interesting stories about Native American medicinal plants and their modern uses, and these accounts are readily found. However, there are other approaches to the medicinal plants of native North America, as described here. Although significant differences existed between the systems developed by the many native groups,2 there were also many broad similarities. There are approximately 21,000 species of plants in North America. Native Americans used more than 2800 of them medicinally.3
Over the past 25 years, I have built a database with 44,775 entries that lists the uses of plants by Native Americans as drugs, foods, dyes, fibers, and so on. The database contains 25,025 entries on uses of drugs, representing a total of 2865 different species of plants. An additional 11,079 entries describe the uses of 3896 species that were used as food. The database was constructed by gathering together several hundred published works on the ethnobotany of Native American people and coding all the information in a systematic way. Because many of these publications were originally obscure and often difficult to find, this database facilitates making such global statements about Native American plant use.
The used portion of the flora (the “medicinal flora”) is a distinctly nonrandom assortment of the plants available. The richest sources of medicines are the sunflower family (Asteraceae), the rose family (Rosaceae), and the mint family (Lamiaceae). By contrast, the grass family (Poaceae) and the rush family (Juncaeae) produce practically no medicinal species. This remarkable volume and extraordinary selectivity demonstrate the falseness of demeaning claims that suggest that Native American medicines were chosen at random, that they seemingly just used everything and stumbled on something useful (like Echinacea or Podophyllum) once in a while.
HEALTH AND DISEASE
To understand the character and effectiveness of a medical system, one must understand the health status of the people who use it. Native Americans were typically very healthy. They generally did not have the degenerative diseases of the heart and circulatory systems so common today; their diets were rich in fiber and carbohydrates and low in fats. They lived vigorous lives that provided hearty exercise on a daily basis. They experienced little cancer. Cancer is largely a modern disease of civilization; although the situation is complex, an apparently necessary condition for cancer is carcinogens, which are largely products manufactured by industrial societies (e.g., organic chemicals and dyes, nuclear radiation). Even current evidence indicates that the traditional Navajo still have lower rates of cancer than surrounding people (Csordas, 1989).
In addition, Indian people had fewer classic infectious diseases, which had ravaged European society over the past two millennia. In large part, many such diseases (e.g., plague, typhoid, smallpox, cholera) are zoonoses, diseases of animals that, under conditions of domestication, underwent evolutionary change and subsequently affected the human keepers of these animals. Native Americans never domesticated animals to any significant degree (the guinea pig and llama of Peru were apparently only coming under domestication in the few hundred years before European contact). Once these diseases were introduced into North America, they devastated native populations, which had no natural immunity to them.4 Until the sixteenth century, when Europeans underwent successive epidemics that regularly killed a quarter or half of the population, Native Americans were spared this devastation.
What medical problems did Native Americans face? In the Southeast and Southwest, evidence suggests a decline in health status after the invention of agriculture as the diet became simpler (less varied), which apparently led to some deficiency diseases. Hunting and gathering people avoided that problem, but they, like Europeans, may have experienced some zoonotic infections, particularly from beaver, and some trichinosis from bears. However, these infections would have been “direct” zoonoses that individuals contracted directly from the infected animal, not “remote” zoonoses, which, once passed to one human, were subsequently passed from person to person. As with rabies, a terrible disease for the individual who contracts it, these direct zoonoses are not serious threats to a whole society because they are not “contagious” in the ordinary sense of the term: from human to human.
Native Americans paid a price for the vigorous life they led. Accidents, sprains, broken bones, cuts, lacerations, and other trauma were common. There was a range of arthritic conditions, with some probably the result of injury and some similar to rheumatoid arthritis. Ample evidence indicates that native peoples engaged in warfare, which would have been a source of serious medical problems. There was a range of occasional problems associated with menstruation, pregnancy, childbirth, and lactation that required attention. Living in smoky houses, it is not surprising that they had a wide range of treatments for irritated eyes and skin; they also treated colds, headaches, cold sores, and bruises, the normal insults of daily life.
HERBAL MEDICINES
To address this range of problems, Native Americans inevitably resorted to medicines based on various plants.5 Although a good deal of research has been done on this ethnobotany, much is difficult to find and use. Most of the research has been done on a “tribe-by-tribe” basis. This situation means that if you are interested in what plants the Iroquois used for medicines and how they used them, you could look in James Herrick’s doctoral dissertation, Iroquois Medical Botany (Herrick, 1977). However, if you were interested in how different cultural groups used the same plant, it was a much more challenging proposition. My database, described earlier, makes this work much more practical.
Every Native American group for which we have any information had a botanical pharmacopeia. Although some were quite small (the Inuit of the Arctic had few plant resources on which to rely), most were quite elaborate, with hundreds of plant drugs used for a broad range of conditions. This straightforward proposition raises a number of much more challenging questions. Native American healers, even into the early twentieth century, regularly knew the identity of 200 or 300 medicinal plants, which they could readily distinguish from the 3000 to 5000 species that grow in any particular area. Among sophisticated and well-educated modern Americans or Europeans, few can identify 200 species of plants of any kind unless they are professional botanists. How did nonliterate people, without reference to botanical keys or floras compiled by professionals, maintain this extraordinary amount of knowledge?
If a Native American discovered, by whatever means, a marvelous medicinal plant that cured a child of a terrible rash and if the plant was very rare and unusual, an annual of uncertain provenience, she might be hard pressed to find it a second time, and harder pressed yet to teach her daughter or niece or neighbor where to find it. Such a plant would be unlikely to become part of the common knowledge of the community. If the situation were compounded by the fact that the plant were drab, with no particularly visible flowers or leaves—an undistinguished, rare, annual forb, for example—it is even less likely that it would become part of common knowledge. Such a proposal can lead to some testable propositions. For example, I predict that, compared with other species, medicinal plants will tend to have the following characteristics:
These criteria do not mean that a tiny, drab, undistinguished, rare annual occurring in one forest in Tennessee could not be part of the Native American medicinal flora. It means it is more likely that a large, common, perennial tree found in 20 states will be used medicinally than would the rare one.
Abundance
I cannot directly test the proposition that “medicinal plants tend to be relatively abundant” because I have no data set listing the relative abundance of North American plants. However, I can test a variation on that proposition, which states that “medicinal plants tend not to be rare and endangered.”
The United States has a law called the Endangered Species Act, which seeks to protect endangered and threatened species of plants and animals. To administer the act, the U.S. Department of Agriculture (USDA) maintains a list of such species (many of which are actually varieties or subspecies). Currently there are 389 species (or subspecies or varieties) on the list in four categories: proposed threatened, threatened, proposed endangered, and endangered. These species are all taxa that, by definition, are found in limited areas, which are infrequent in their ranges. Two of 2572 medicinal species (0.08%) are on the list, whereas 387 of the remaining 28,543 taxa (species, subspecies, varieties, quads) in North America (1.3%) are on the list. This difference is highly statistically significant. By this admittedly limited test, medicinal plants tend not to be rare and unusual. If it were possible to measure directly the abundance of a good sample of American species, a much better test of this proposition could be performed.
Distribution
In addition, evidence accumulated by the USDA is available for the distribution of North American plant species. There is information on the presence or absence of species in 60 states and territories and 12 Canadian provinces. Species used as drugs are found in an average of 16 states or provinces, whereas species not used as drugs are found in an average of only 5 states. Drug plants are much more widespread than are nondrug plants.
Growth Habit
Evidence indicates, first, that among native North Americans, a disproportionate share of medicinal plants have a perennial rather than annual growth habit. There are many more perennials (12,284) than annuals (3060); 16% of the perennials are used medicinally, whereas only 8.7% of the annuals are used medicinally.
Growth Form
The most commonly used growth form is trees and shrubs, followed by forbs, vines, and grasses. Table 35A-1 shows the numbers and percentages of each type. Although these differences may not seem large, they are, again, highly statistically significant; a given tree or shrub is 30% more likely to be used as a medicine than is a given forb.
Flavor
Circumstantial evidence from a number of cases indicates that medicinal plants often have a distinctive and, in particular, bitter taste. This cannot be easily tested because no evidence is available on the flavors of plants not used as medicines (because botanists do not consider a plant’s flavor to be an important characteristic).
Showiness
Finally, there is evidence that plants used for medicine by Native Americans are more showy or visible than other plants. This test is indirect. As I became more interested in flower gardening, I had a sense that most of the garden plants were also in my database of medicinal plants. Why do we put this plant in a flower garden, and not that one? Generally it is because the garden species has beautiful or unusual or colorful flowers or leaves or scent or growth habits or a similar distinction; garden plants are typically recognizable and distinctive. Many of our garden varieties are much different from their wild ancestors, but the hybridizers rarely began with nothing. I reasoned that medicinal plants would be more likely to show up in gardens than would plants not used medicinally.
I looked among my garden books and found Ortho’s Complete Guide to Successful Gardening. The book has a 122-page encyclopedic chart of plants of value in a garden, alphabetically arranged from Abelia to Zoysia. I checked genera in the gardening book, which also appeared in a standard list of the flora of North America (Kartesz, 1994). There are 3138 genera in this list, of which 852 appear in my database of medicinal plants. In addition, there were 423 genera of plants listed in the garden book that appear on the Kartesz checklist (a few items in the book were not in the checklist because they do not appear outside of gardens). If all were distributed randomly, and if medicinal plants were not favored for use in the garden, we would predict that 115 of the garden plants would have appeared on the list of 852 medicinal species. However, there are actually almost twice that many, 213, again a highly statistically significant difference. Medicinal plants tend to be visible, recognizable, and showy (Box 35A-1).
BOX 35A-1 Four Native American Medicinal Plants
Echinacea angustifolia
There are a total of 123 records for Echinacea, the coneflowers, in my database. They represent 26 distinctly different use categories, such as “analgesic,” “antirheumatic,” and “cold remedy.” There are 18 different tribes represented in those data and 93 combinations of tribe and use (e.g., “Pawnee analgesic,” “Crow cold remedy”). Nine different tribes are reported to have used Echinacea as an analgesic. Some tribes used it several different ways: The Winnebago used it in a wash for pain from burns and also put it in a smoke treatment for headaches. The Ponca used it the same two ways.
Toxicodendron radicans
Poison ivy is a common North American plant that causes serious, itchy rashes on many people. Children are taught “leaflets three; let it be.” The toxic chemical urishol is found throughout the plant: in the soft woody stem, the leaves, and the berries. It is particularly dangerous when burned with dead leaves in the fall; contact with the smoke can also cause serious allergic reactions. Several other members of this genus have similarly noxious properties, including T. diversilobum (Pacific poison oak), T. pubescens (Atlantic poison oak), and T. vernix (poison sumac).
It may be somewhat surprising, therefore, to discover that Native American people found this genus to be useful as a medicine. There are 57 listings of Toxicodendron in the database. Although some of these listings indicate simply that the people recognized the plant as being poisonous, others found medicinal uses for the plants. The Yuki of California, for example, used Pacific poison oak to treat warts, whereas the Cherokee used a decoction of the bark of Atlantic poison oak as an emetic. The Kiowa Apache rubbed poison ivy leaves over boils or other skin eruptions, and the Houma of Louisiana took a decoction of the leaves as a tonic and “rejuvenator.” In homeopathic preparations, Toxicodendron is a leading remedy for several common symptoms.
Geranium maculatum
Eight species of wild geraniums were used medicinally by Native American people (note that these are not the same as the common ornamental plants often called geraniums, which are actually members of genus Pelargonium). The most widely used is Geranium maculatum, the wild cranesbill. This plant produces a long, pointed seed that has a series of small but distinct hooks on the end, which probably serve to catch the seeds in the fur of passing animals to aid in their dispersal. However, these hooks also provide the Iroquois with a rationale for using a poultice of the roots of this plant on chancre sores; the “hooklike and ensnaring qualities” of the plant (implied by its hooked seeds) are precisely what to use on a “loose, running, everted” sore. The plant is therefore a “meaningful” medicine for the Iroquois. The roots also contain substantial quantities of tannin, which would probably be an effective treatment for sores. Medicines typically have this double quality of “meaning and chemistry” in all medical systems.
Daucus carota
The wild European carrot, or Queen Anne’s Lace, is a common medicine for Native Americans. Native Americans came to use a number of introduced species; other common European plants that became widely used are mullein (Verbascum thapsus), curly dock (Rumex crispus), catnip (Nepeta cataria), and the common tansy (Tanacetum vulgare). The Delaware and Mohegan used wild carrot to treat diabetes; the Iroquois used it as a diuretic; and the Cherokee used an infusion of the plant as a wash for swellings.
SUMMARY
The medicinal knowledge of the native North American people is extraordinary. Just how this knowledge was developed remains a mystery. Native American peoples are thought to have come from Asia; the flora of Asia is similar to that of North America in many ways. It is likely that the first migrants to the New World brought detailed knowledge of medical botany, much of which was applicable to this new flora.
Most remarkable, however, may be: I am unaware of any significant medicinal use of any indigenous American plant species that was not used medicinally by one or another Native American group. An interesting example involves recent research on taxol, a substance of great potential medical value found in the common yew, Taxus brevifolia, and the Canadian yew, Taxus canadensis. Taxol has shown substantial effect in the destruction of tumors in several forms of cancer, particularly ovarian cancer, a highly refractory form. Native Americans did not use yew to treat cancer, since cancer was probably very rare (see previous discussion), but they did use it for a variety of other conditions, including skin problems, wounds, rheumatism, and colds.
In general, if one is interested in finding potentially useful botanical chemicals from the North American flora, it would be wise to focus first on that portion of the flora used by Native Americans. Their experience and knowledge can yet guide our scientific efforts to enhance human health.
1. For a review of this situation, see the detailed article by Blumenthal and King (1996).
2. Many fine works on the medical systems of particular groups are available, although they are sometimes difficult to find. Perhaps the finest is by James Herrick on the Iroquois (1977). For a superb overview of the range of forms of treatment and understanding of illness, see Vogel’s classic work, American Indian Medicine (1970).
3. The most comprehensive available listing of Native American medicinal plants is Moerman’s Medicinal Plants of Native America (1986). For a more recent and much larger database, see Moerman’s Native American Ethnobotany (1997; also available at www.umd. umich.edu/cgi-bin/herb
4. For a fascinating and controversial review of the impact of European diseases on Native Americans, see Calvin Martin’s Keepers of the Game (1978). The classic work on the zoonotic origins of modern diseases is R. N. Fiennes’ Zoonoses and the Origins and Ecology of Human Diseases (1978).
5. There were some nonplant substances that were used medicinally. Castoreum from beaver was used for various conditions, and some minerals and clays were used as well. However, the preponderance of medicinal substances came from plants.
6. The definitive treatment of non-Western botanical knowledge is Brent Berlin’s Ethnobiological Classification (1992); the best modern treatment of the problems of the origins of knowledge of food and drug plants is Timothy Johns’ With Bitter Herbs They Shall Eat It (1990).
7. The next three sections on distribution, habit, and form are based on data from the USDA National Plants Database (http://trident.ftc.nrcs.usda.gov/plants/plntmenu.html).
8. A detailed comparison of the ethnobotany of North America and China awaits scholarly attention. A preliminary account by James Duke (in Duke and Ayensu, Medicinal Plants of China, 1985) is provocative.
Csordas T. The sore that does not heal cause and concept in the Navajo experience of cancer. J Anthropol Res, 45. 4, 1989. 457-485
Herrick JW. Iroquois medical botany. University Microfilms International (dissertation): Ann Arbor, 1977.
Kartesz J. Synonymized checklist of the flora of North America. Portland, Ore: Timber Press, 1994.
Berlin B. Ethnobiological classification principles of categorization of plants and animals in traditional societies. 1992. Princeton University Press, Princeton, NJ.
Blumenthal M, King P. The agony of the ecstasy herbal high products get media attention, HerbalGram. 1996. J Am Botanical Council Herb Res Found 37.
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Duke JA, Ayensu ES. Medicinal plants of China, 1985. Reference Publications, Algonac, Mich.
Fiennes RN. Zoonoses and the origins and ecology of human diseases. New York: Academic Press, 1978.
Johns T. With bitter herbs they shall eat it chemical ecology and the origins of human diet and medicine. 1990. University of Arizona Press, Tucson.
Martin C. Keepers of the game Indian-animal relationships and the fur trade. 1978. University of California Press, Berkeley.
Moerman DE. Native American ethnobotany. Portland, Ore: Timber Press, 1997.
Moerman DE. The medicinal flora of native North America an analysis. J Ethnopharmacol, 31. 1991. 1-42
Vogel VJ. American Indian medicine. Norman: University of Oklahoma Press, 1970.
Wrangham RW, Goodall J. Chimpanzee use of medicinal leaves. In: Heltne PG, Marquardt L, editors. Understanding chimpanzees. Chicago: University of Chicago Press, 1987.