MEDICINAL HERBS: The Confusing Quagmire of Names
 
 

Let's face it. Plant names can be ambiguous and confusing. Today there are three major systems of naming herbs, including medicinal herbs. Because each system is widely encountered by quite different groups of writers, practitioners or consumers, there is considerable confusion as to the "correct" names of herbs. Many books, prescriptions or over-the-counter (OTC) preparations do not include an adequate "crosswalk" or index of the names to help the consumer more easily determine exactly which herbs are being discussed or consumed. The situation is especially difficult with respect to herbs used in traditional Chinese medicine.

1. VERNACULAR or COMMON NAMES. Obviously these names are the most widely known and used. Many have a fascinating etymological origin, in addition to the plants themselves having an interesting history of use as medicines. They may be written in any language or typescript. English common names today often derive from Old English or Anglo-Saxon, but many "English" names were originally from other languages such as Latin, French, Chinese, Norwegian, Sanskrit, Greek or other indigenous languages such as Cherokee, Mayan or Yanomamo. Herb names often heard today in America and other English-speaking countries include comfrey, garlic, evening primrose, red clover, St.John's wort (wort is OE for plant), saw palmetto, licorice, devil's claw, chicory, borage, wormwood, cohosh and rosemary. Chinese herb names may be variations on these names or they may be original Chinese common names translated into English. Also, the transliteration of the Chinese characters into Pinyin, Wade-Giles, or other systems may further complicate the correct use of these common names (see Burley, 2000, SRAM 4(2):29-31.)

Frequently, the common names simply are changes or corruptions of a name in another language. For example, English "dandelion" was derived from French "dent de lion." English "fennel" is derived from Old English, but was originally Latin "foeniculum," from "foenum" for hay. Similarly, English "mullein" derives from French moulaine. "Tansy," a vernacular name used for several different plant species, derives via old French from the Greek word athanasia, for immortality, presumably due to the health-inducing effects of some plant in ancient Greece. "Cleavers" and "bedstraw" are two common names for species in the genus Galium, and Galium aparine is known by more then 30 vernacular names in England alone. It's not surprising that there can be considerable confusion! Knowing the history of the names helps us understand this dilemma and can help clarify the names of plants used in herbal medicine.

2. LATINIZED NAMES. A second system of names for medicinal herbs derives from the long-standing and initially quite reasonable medical practice of using some form of the Latin, especially in Europe in the Middle Ages. This naming system is also called pharmaceutical, homeopathic, or commercial Latin. Unfortunately, it is a well-intentioned but very inadequate naming system which still is found widely in pharmacopoeias, some medical texts and research papers, homeopathy, popular herb books, and especially in the prescriptions and patent formulas of Chinese herbal medicine. Examples of latinized herb names under this system include: Cuscutae, Curcumae, Plantaginis, Asari cum Radice, Fructus Citri Sarcodactylis, Cimicifugae, Fructus Zizyphus, Radix Dipsaci, and Semen Sterculiae. Although it may be possible to determine exactly which plant species is being referred to in this system, the latinized name is generally incomplete or insufficient and can lead to confusion over which species is involved.

From the examples above, "Cuscutae" clearly refers to a plant in the botanical genus Cuscuta, but it does not indicate which species may be involved. Botanists currently recognize about 145 species in this genus. Similarly, "Cimicifugae" clearly refers only to the botanical genus Cimicifuga, which contains about 18 species in the buttercup family, the Ranunculaceae. It could be referring to Cimicifuga racemosa, known in American vernacular as black cohosh, or perhaps to some other species. Lastly, "Radix Dipsaci" obviously refers to the root (radix) of a species in the genus Dipsacus, but it is unclear which of about 15 species of Dipsacus is meant here. This system of latinized names sometimes is an improvement over the system of common names, but often it is even less clear and informative than using the common names. When looking for herb information in the older literature, particularly in the older editions of the pharmacopoeias and materia medicas, one must be careful to examine the latinized name and to note whether it is possible to determine precisely which species is being considered. Too often there is no clear indication.

3. NAMES in MODERN BOTANICAL LATIN. For the past 250 years, scientists and botanists have recognized this difficult problem of many names for a single plant species or several species having the same vernacular name. To avoid this confusion, a comprehensive botanical Latin naming system was developed and now functions under the rules and recommendations of the International Code of Botanical Nomenclature (there is a similar code for animal names in Latin.) The Code is updated every six years, most recently in 1999 in St.Louis, Missouri. This is the ONLY naming system which reliably and uniquely refers to a particular herb species and to no other plant, and it is the only system which is universally understood and used by botanists and researchers worldwide. The names are based on specific plant material preserved in herbaria ("type" specimens). These names are accepted or rejected under very specific rules of priority, validity, orthography, etc. Because of its utility and clarity, ultimately this is the only naming system which always must be used in referring to herb species. Other systems can be used also, of course, but they should be "crosswalked" and cross-indexed with the botanical Latin names. Any research paper or reference book that uses only a vernacular name such as "ginseng" or an incomplete latinized pharmaceutical name such as "Cortex Moutan Radicis" is immediately suspect due to ambiguity, and the information or results reported in that source are nearly worthless if the species cannot be determined with accuracy. Worse, these incomplete names can be misleading or dangerous if a reader or consumer assumes that some other herb species is being referred to.

Herb names in botanical Latin must be written in very precise ways, for reasons which may seem arcane or even silly but which are agreed upon because they have been found necessary to avoid confusion. Full explanation of the nomenclature system is not possible here, but the following notes may be helpful.

The botanical Latin name is always in two or three parts (binomials and trinomials); it is never a single word or name. The first part is the name of the botanical genus and always is written with an initial capital letter. The second part is a word which identifies a particular species in that genus, and it is never capitalized today. Thus the binomial name Tanacetum parthenium, or feverfew in English, refers to one species in the genus Tanacetum. Tanacetum vulgare is another species, or European tansy, now a common roadside weed in America and elsewhere. The binomial name sometimes is abbreviated, such as T. parthenium, if the generic name has been written previously and is clearly evident. Both of these "tansy" species have a history of medicinal use, although neither is adequately researched and documented by today's clinical standards.

Worldwide research continues on thousands of plant species, their evolutionary relationships and their classification. Because of this, inevitably there are some Latin name synonyms. Under the procedures of the International Code, this difficulty can be overcome in systematic fashion. As throughout modern science, the system over time is constantly improving and is self-correcting. Errors get weeded out (no pun intended).

Technically, the full botanical name for an herb species includes the name of the botanist who first described the species and subsequent authors who may have created a new name for that species, by placing it in a different genus. Thus we have Panax quinquefolius L, one species of "ginseng" first named by Linnaeus, and that name is still accepted today for American ginseng. (Because Linnaeus named so many species, his name is usually abbreviated.) Crataegus laevigata (Poir.)DC. refers to a species of hawthorn originally described by Poiret in a different genus but later classified in the genus Crataegus by the botanist deCandolle. The reason it is necessary to include this author citation in the Latin name is that it is the only way to be sure exactly which species (or taxon) is being referred to (recall that these Latin names are based on specific "type" material kept in herbaria.) Today, the best and most authoritative herb books and references include this full botanical Latin name plus author citation for any herbs being discussed in depth. Lastly, the Latin name of the herb should be set off in italics (if your typescript software allows this) or in bold, or both.

SOME USEFUL GUIDELINES. This widespread problem of confusion over herb names is becoming better known throughout the herbal medicine community, and eventually the problem will lessen as mistakes become evident and as the botanical Latin is included in more reference material. Meanwhile, I would recommend the following guidelines to health professionals, researchers, authors and consumers:

1. When using reference books and the technical literature, always look for the botanical Latin name to identify the herb species involved. A few common names like "Uva-Ursi" and "ginkgo" are not ambiguous because they refer only to Arctostaphylos uva-ursi and Ginkgo biloba, but other single-word common names like ginseng, nettle, clover, cohosh, tansy, mint, sage, wormwood, chamomile, ginger and coltsfoot, if used alone, can be very ambiguous. Also, some generic names are used alone as a common name are they are ambiguous also: angelica, ephedra, valerian(a), and echinacea are good examples, In short, look carefully at the names. Much of the popular, non-technical literature does not show the botanical Latin names, and in many cases, the correct identification of the herb in question may not be possible.

2. In research and writing for publication, always use the full botanical Latin binomial name, preferably with the author citation attached. Use any other common or Latinized names written in any language or typescript also, but not without the botanical Latin name and only if you are sure it will not lead to confusion. Despite its air of professionalism, using only the generic name in botanical Latin, such as Ephedra, Artemisia, Hibiscus, Damiana, Arnica, Lobelia, Panax or Arctostaphylos, is not adequate because these names standing alone leave open the question of which species in the genus is being referred to.

3. If you receive herbal prescriptions from a medical practitioner or herbalist, ask specifically which herbs are being prescribed. If the practitioner cannot or will not give you this information clearly and unambiguously, then you should question the reliability and professionalism of that practitioner. Many practitioners will not be able to recite the Latin names with ease, but any literature, information sheets, prescriptions and labels should include the full botanical Latin names for your information.

4. In general, ask questions until you determine which herb species are involved. Too many herbal enthusiasts and promoters are glossing over this name confusion as if it were of no importance. This is unprofessional at best. If a bookstore is selling a popular herb book in which none of the herbs are clearly identified by botanical Latin names in addition to vernacular names, bring this to the proprietors' attention and urge them to consider no longer stocking that title or stocking instead books which are a bit more rigorous and authoritative. Point out that many names like "mint," "chamomile," "cohosh," "citrus," "borage," "kelp," or "ginseng" when used alone are misleading and do not tell you which herbs are involved.

ENVOI

With more interest from the public and with greater demand for reliable, accurate healthcare information, the herb industry and herbal medicine profession worldwide will eventually begin to clear up much of this confusion in herb names. However, this will take some time. Chinese herbal medicine, Indian Ayurvedic medicine, and other traditional systems of herb use will continue to present serious problems in the correct identification and naming of herbs. Ultimately, all herbal medicine must use the international system of Latin names under the Code, to avoid confusion, to minimize adverse events due to misidentification, and to guarantee the reliability, necessary repetition, and accuracy of clinical research.

REFERENCES

(Note: Dictionaries, particularly the Oxford English Dictionary, are delightful gold mines of etymological information about plant names and their origins. However, they must be used with considerable caution because the taxonomy and nomenclature of the plants often is simply incorrect or quite out-of-date.)

1. Atherton DJ, et al. Need for correct identification of herbs in herbal poisoning. Lancet. 1993; 341: 637-638.

2. Bensky D, Gamble A. Chinese Herbal Medicine Materia Medica, rev.ed. Seattle, WA: Eastland Press; 1993. (One of the few TCM herbal medicine reference books that include the full botanical Latin names.)

3. Borins M. The dangers of using herbs. What your patients need to know. Postgrad Med. 1998;104(1):91-95.

4. Burley B. Chinese herbs: some things to remember, Scientific Review of Alternative Medicine. 2000; 4(2): 29-31.

5. But, PP-H. Need for correct identification of herbs in herbal poisoning. Lancet. 1993; 341:637.

6. DeSmet PA. The role of plant-derived drugs and herbal medicines in healthcare. Drugs. 1997; 54(6):801-840.

7. Foster S, Tyler, V. Tyler's Honest Herbal. 4th ed. New York, NY: Haworth Herbal Press; 1999. (Probably the best of the very few reliable and popular herb books on the market today, with correct use of the Latin binomials. This is the recent fourth edition of a standard herb reference book.)

8. Hu S-Y, Kong YC, But PP-H. An Enumeration of Chinese Materia Medica, 2nd ed. Hong Kong. The Chinese University Press; 1999. (By far the most useful, comprehensive and well-indexed listing of plants and non-plant "herbs" used today in traditional Chinese medicine.)

9. Mabberley DJ. The Plant Book: A Portable Dictionary of the Vascular Plants. 2nd ed. Cambridge, UK: Cambridge university Press; 1997. (A very useful index of plant names, with emphasis on the Latin names and considerable information about the families, genera, and some species. Many vernacular names also. A major reference for plant names.)

10. Stearn WT. Botanical Latin, 4th ed. Portland, OR: Timber Press. 1992. (The most useful reference for how Latin is used in botanical names and in the international system of botanical nomenclature. Not a list or index of names, however.)

11. Stearn WT. Stearn's Dictionary of Plant Names for Gardeners. London, UK: Cassell; 1992. (An entertaining and very useful popular book with many of the herb generic names and their origins.)
 

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Bill Burley is a conservation biologist with a special interest in the history and names of medicinal herbs. E-mail: billburley@pioneernet.net