HERBAL
MEDICINEENCYCLOPEDIA OF
US_001_003_Half_Full_title.indd   1 26/02/16   4:42 pm
US_001_003_Half_Full_title.indd   2 26/02/16   4:42 pmHERBAL
MEDICINEENCYCLOPEDIA OF
Andrew chevallier
fnimh
US_001_003_Half_Full_title.indd   3 26/02/16   4:42 pm
 
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IMPORTANT NOTICE 
Do not try self-diagnosis or attempt self-treatment for serious or long-term problems without first consulting 
a qualified medical herbalist or medical practitioner as appropriate. Do not take any herb without first 
checking the cautions in the relevant herb entry (see  pp. 56–283) and the Essential Information on  
pp. 298–299. Do not exceed any dosages recommended. Always consult a professional practitioner if 
symptoms persist. If taking prescribed medicines, seek professional medical advice before using herbal 
remedies. T ake care to correctly identify plants and do not harvest restricted or banned species. So far as the 
author is aware, the information given is correct and up to date as of July 2016. Practice, laws, and regulations 
all change, and the reader should obtain up-to-date professional advice on any such issues. In addition, this 
book contains general information on growing cannabis, which is a controlled substance in North America 
and throughout much of the world. As the use and cultivation of cannabis and its derivative products can 
carry heavy penalties, you should research your local laws before using the information in this book. The 
author and the publisher expressly disclaim any liability, loss, or risk, personal or otherwise, which is incurred 
as a consequence, directly or indirectly, of the use and application of any of the contents of this book. Third American Edition, 2016
First American Edition, 1996
This edition published in the United States in 2016 by  
DK Publishing, 345 Hudson Street, New Y ork, New Y ork 10014
Copyright © 1996, 2001, 2016 Dorling Kindersley Limited
Text copyright © 1996, 2001, 2016 Andrew Chevallier 
DK, a Division of Penguin Random House LLC 
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photocopying, recording, or otherwise), without the prior written permission of the copyright owner. Published in Great Britain by Dorling Kindersley Limited. A catalog record for this book is available from the Library of Congress. ISBN: 978-1-4654-4981-8
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FIRST EDITION
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US_004-005_Imprint_Contents.indd   4 26/02/16   4:42 pmContents
Introduction
THE DEVELOPMENT OF HERBAL MEDICINE
How Medicinal Plants Work
Active Constituents
Quality Control
Early Origins to the 19th Century
20th Century Onward
Herbal Traditions of the World  
Europe  
India and the Middle East  
China, Japan, and Southeast Asia 
Africa  
Australia and New Zealand 
North America  
South America
KEY MEDICINAL PLANTS
A visual guide to 1 00 key herbs from around the world with
details of their habitat, constituents, actions, traditional
and current uses, and information on the latest research. Also included are key preparations and practical self-help uses. OTHER MEDICINAL PLANTS
450 other herbs from different herbal traditions with descriptions  
of their therapeutic properties and past and present uses. HERBAL REMEDIES FOR HOME USE
Growing Medicinal Plants
Harvesting & Processing
Making Herbal Remedies
Using Herbal Remedies Safely
Remedies for Common Ailments
Consulting an Herbal Practitioner
Glossary 
Bibliography 
General Index
Index of Herbs by Ailment
Useful Addresses & Acknowledgments6
8
10
14
17
18
28
32
32 
36 
40 
44 
46 
48 
52 
54
156
284
286
288
290
298
299
320
321 
322 
323 
332 
336 
US_004-005_Imprint_Contents.indd   5 26/02/16   4:42 pm
6Introduction
In the twenty years since the first edition of this encyclopedia in 1996, herbal medicine  
has gone through unprecedented change. Herbs, which have always been the principal form 
of medicine in developing countries, have again become popular in the developed world,  as people strive to stay healthy in the face of chronic stress and pollution, and to treat illness with medicines that work in concert with the body’s defenses. A quiet revolution has been taking place. Tens of millions of people now take herbs such as ginkgo (Ginkgo biloba, p. 100)  
to help maintain mental and physical health, and increasingly people consult trained herbal professionals and naturopaths for chronic or routine health problems. Increasingly too, scientific evidence is accumulating to show that herbal medicines can provide treatment that  is as effective as conventional medicines but with few side effects. Sales of herbal medicines continue to grow year after year—by over 50 percent in the U.S. since 2000—and several mainstream pharmaceutical companies now manufacture and market herbal medicines. Plant Medicines
The variety and sheer number of plants with therapeutic properties are quite astonishing. Some 50,000 to 70,000 plant species, from lichens to towering trees, have been used at  
one time or another for medicinal purposes. Today, Western herbal medicine still makes use  
of hundreds of native European plants, as well as many hundreds of species from other continents. In Ayurveda (traditional Indian medicine) about 2,000 plant species are considered to have medicinal value, while the Chinese Pharmacopoeia lists over 5,700 traditional medicines, mostly of plant origin. About 500 herbs are still employed within conventional medicine, although whole plants are 
rarely used. In general, the herbs provide the starting material for the isolation or synthesis  
of conventional drugs. Digoxin, for example, which is used for heart failure, was isolated from common foxglove (Digitalis purpurea, p. 202), and the contraceptive pill was synthesized from constituents found in wild yam ( Dioscorea villosa, p. 91). Ecological Factors
The increased use of medicinal herbs has important environmental implications. Growing 
herbs as an organic crop offers new opportunities for farmers, and sometimes, especially  
in developing countries, opportunities for whole communities. In northeastern Brazil,  for example, community-run herb gardens grow medicinal herbs that are sold to local hospitals. Doctors at the hospital then prescribe these medicines for their patients. The rise in popularity of herbal medicines, however, also directly threatens the survival  of some wild species. Demand for goldenseal (Hydrastis canadensis, p. 105) has become so  great that it now fetches around $140 a pound (£170 a kilo). It was a common plant in the woodlands of northern America two centuries ago, but is now an endangered species, with its survival in the wild threatened by overcollection. This example is by no means unique, and, sadly, many species are similarly threatened across the planet. The extinction of plant species as a result of over-intensive collecting is nothing new. The herb silphion, a member  of the carrot family, was used extensively as a contraceptive by the women of ancient Rome. US_006-007_Introduction.indd   6 26/02/16   4:42 pm7Silphion proved difficult to cultivate and was gathered from the wild in such large quantities 
that it became extinct during the 3rd century ce. Today, if herbal medicine continues to grow at its present rate, it is imperative that 
manufacturers, suppliers, practitioners, and the public use only produce that has been 
cultivated or wildcrafted in an ecologically sensitive manner. About This Book
In the past, books on herbal medicine have tended to focus either on the traditional and 
folkloric use of plants or on their active constituents and pharmacology. The Encyclopedia  
of Herbal Medicine , which features over 550 plants, aims to cover both aspects. It discusses 
each plant’s history, traditions, and folklore, and explains in simple terms what is known from 
scientific research about its active constituents, actions, and potential new uses. It is easy when concentrating on the scientific aspect of herbal medicine to forget that 
much, in some cases all, that we currently know about a particular plant results from its 
traditional use. Moreover, even when a plant has been well researched, herbal medicines are 
so complex and variable that what is currently known is rarely definitive, but rather a sound 
pointer as to how it works. Sometimes the traditional use, insofar as it is based on the 
experience of practitioners, provides an insight into how best to use an herb that is missing 
from scientific knowledge alone. Herbal medicine is, after all, both a science and an art. In choosing the plants profiled in the Encyclopedia , the aim has been to select herbs that are 
commonly used in different parts of the world and are considered to have particular health 
benefits. The index of key medicinal plants (pp. 54–155) contains many herbs that are 
readily available in health stores and pharmacies, for example St. John’s wort ( Hypericum 
perforatum , p. 106). It also includes herbs that are more commonly known as foods, such as 
lemon ( Citrus limon , p. 82), but which, nonetheless, are valuable medicines. The index of other 
medicinal plants (pp. 156–283) contains some less commonly known but important medicinal 
herbs, such as andrographis ( Andrographis paniculata , p. 167), a traditional Indian medicinal 
plant that stimulates recovery from infection and supports normal liver function. A global overview of the history of herbal medicine puts the development of different 
herbal traditions from earliest origins to the present day into perspective. This is complemented 
with features on herbal medicine in Europe, India, China, Africa, Australia, and the Americas, 
providing a rounded picture of herbal medicine worldwide. Herbal medicine is nothing if not practical in its approach, and the Encyclopedia  has a 
detailed self-help section with advice on preparing and using herbal medicines to treat  
a range of common health problems. If more people come to appreciate the immense richness of the world of herbal  
medicine and are able to benefit from the curative properties of medicinal herbs, this  
book will have achieved its aim. US_006-007_Introduction.indd   7 07/04/16   4:36 pm
US_008-009_The_Development_of_Herbal_Medicine.indd   8 26/02/16   4:42 pmThe 
developmen T
of herbal
medicine
From the earliest times, herbs have been prized for their pain-relieving and 
healing abilities, and today we still rely on the curative properties of plants 
in about 75 percent of our medicines. Over the centuries, societies around 
the world have developed their own traditions to make sense of medicinal 
plants and their uses. Some of these traditions and medicinal practices may 
seem strange and magical, others appear rational and sensible, but all are 
attempts to overcome illness and suffering, and to enhance quality of life. “a wise man ought  
to realize that health  
is his most valuable  
 possession.”  
Hippocrates
US_008-009_The_Development_of_Herbal_Medicine.indd   9 26/02/16   4:42 pm
10
The developmen T of herbal medicineHow Medicinal Plants Work
Many of the thousands of plant species growing throughout the world have medicinal  
uses, containing active constituents that have a direct action on the body. They are used  both in herbal and conventional medicine and offer benefits that pharmaceutical drugs  often lack, helping to combat illness and support the body’s efforts to regain good health. There is no doubt that in extreme situations, the treatments 
devised by modern medicine can offer an unparalleled opportunity to relieve symptoms and save lives. A newspaper article in 1993 described the terrible conditions in a hospital in war-torn Sarajevo, the capital of Bosnia-Herzegovina. Deprived of conventional medical supplies and drugs, the doctors were forced to use a well-known European herb, valerian (Valeriana officinalis, p. 148), as a painkiller for the wounded and as an anesthetic. Valerian is an effective herbal medicine for anxiety and nervous tension, but it is woefully inadequate as an analgesic or anesthetic. Orthodox pharmaceutical medicines sustain life and counter 
infections in situations where other types of treatment  
may have little to offer. Modern surgical techniques, such as keyhole surgery and plastic surgery, and the whole range of diagnostics and of life-support machinery now available, can  
all be used to improve the chances of recovery from serious illness or injury. The Benefits of Herbal Medicine
Y et despite the dramatic advances and advantages of conventional medicine, or biomedicine as it is also known,  
it is clear that herbal medicine has much to offer. We tend  to forget that in all but the past 70 years or so, humans  
have relied almost entirely on plants to treat all manner  
of illnesses, from minor problems such as coughs and colds  
to life-threatening diseases such as tuberculosis and malaria. Today, herbal remedies are coming back into prominence because the efficacy of conventional medicines such as antibiotics, which once had near-universal effectiveness against serious infections, is on the wane. Over the years, infectious organisms have developed resistance to synthesized drugs, and the herb sweet wormwood (Artemisia annua, p. 67) and  
its active constituent artemisinin, for example, are now the standard treatment for malaria in tropical areas where  
the protozoa causing the infection no longer respond to conventional treatment. Herbal medicine often complements conventional 
treatments, providing safe, well-tolerated remedies for chronic illnesses. It is experiencing a dramatic renaissance in Western countries, partly because no effective conventional treatment as yet exists for many chronic illnesses, such as asthma, arthritis, and irritable bowel syndrome. In addition, concern over the side effects of biomedicine is encouraging people  to look for more gentle forms of treatment. It is estimated that 10–20% of hospital patients in the West are there due to the side effects of conventional medical treatment. Using Herbs Wisely
Most commonly used herbs are extremely safe to use. But some plants can produce side effects and, like all medicines, herbal remedies must be treated with respect. It is essential to take or use certain plants only under the guidance of a well-trained practitioner, to avoid adverse consequences. Ma huang (Ephedra sinica, p. 95), for example, can be extremely toxic at the wrong dosage, and comfrey (Symphytum officinale, p. 138), a very popular herb in the 
past, is thought to cause severe or even fatal liver damage  
in rare circumstances. When an herbal medicine is used correctly, however, the chances of developing a serious side effect are remote. Potent Plant Chemicals
The ability of an herbal medicine to affect body systems depends on the chemical constituents that it contains. Scientists first started extracting and isolating chemicals from plants in the 18th century, and since that time we have grown accustomed to looking at herbs and their effects in terms of the active constituents they contain. This Encyclopedia  
is no exception, providing details of all the main active constituents of the medicinal herbs featured and explaining their actions. Opium poppy fields in Tasmania. Opium, derived from the seed capsules of the opium 
poppy, yields the narcotic alkaloids morphine and codeine, powerful painkillers that are widely used in conventional medicine. US_010-013_How_Medicinal_Plants_work.indd   10 26/02/16   4:42 pm11 How Medicinal Plants workResearch into isolated plant 
constituents is of great 
importance, for it has given rise 
to many of the world’s most 
useful drugs. Tubocurarine, the 
most powerful muscle relaxant 
in existence, is derived from 
pareira ( Chondrodendron 
tomentosum , p. 189), and the 
strongest painkiller of all, 
morphine, comes from opium 
poppy ( Papaver somniferum ,  
p. 244). Many anesthetics  
are also derived from plants—
for example cocaine comes 
from coca ( Erythroxylum  
coca, p. 206). Today, biomedicine still  
relies on plants rather than  
the laboratory for at least 25%  
of its medicines, and many of 
these are among the most effective of all conventional drugs. It is hard to think of a world deprived of the antimalarial 
properties of quinine (derived from Cinchona  spp., p. 80); or 
the heart remedy digoxin (from Digitalis  spp., p. 202); or the 
cough-relieving properties of ephedrine (from Ephedra sinica , 
p. 95), which is present in many prescription and over-the-
counter cold remedies. These and many other conventional 
medicines are all derived from isolated plant constituents. Value of Whole Plants
Although it is important to understand the actions of 
individual active constituents, herbal medicine, unlike bio-
medicine, is ultimately about the use and actions of whole 
plants—medicines that are literally god- or goddess-given, rather than developed in a laboratory. In the same way that 
taking a watch apart and identifying its key parts will not show 
you how it works as a whole, dividing up a medicinal herb 
into its constituent parts cannot explain exactly how it works 
in its natural form. The whole herb is worth more than the 
sum of its parts, and scientific research is increasingly showing 
that the active constituents of many herbs, for example those 
in ginkgo ( Ginkgo biloba , p. 100), interact in complex ways to 
produce the therapeutic effect of the remedy as a whole. Plants contain hundreds, if not thousands, of different 
constituent chemicals that interact in complex ways. Frequently, we simply do not know in detail how a particular 
herb works—even though its medicinal benefit is well 
established. The pharmacological approach to understanding 
how whole herbs work is like working on a puzzle where only 
some of the pieces have been provided. Furthermore, 
although it is very useful to know that a plant contains certain 
active constituents, such information can be misleading on its 
own. For example, Chinese rhubarb ( Rheum palmatum ,  
p. 126) is a commonly used laxative, containing 
anthraquinones that irritate the gut wall and stimulate bowel 
movement. This laxative effect, however, occurs only when 
large quantities of the herb are used. At lower doses other 
constituents, notably tannins, which dry and tighten up 
mucous membranes in the gut, have greater effect. As a 
result, Chinese rhubarb works in two apparently opposite 
ways depending on the dosage: as a laxative at moderate to 
high doses; to treat diarrhea at a lower dose. This example reveals a couple of fundamental truths  
about herbal medicine. Firstly, the experience of the herbal 
practitioner and of the patient often provide the most 
reliable guide to the medicinal effect of individual herbs. Secondly, the value of a medicinal herb cannot be reduced 
simply to a list of its active constituents. Plants as Foods & Medicines
In general, the human body is much better suited to 
treatment with herbal remedies than with isolated chemical 
medicines. We have evolved side-by-side with plants over 
hundreds of thousands of years, and our digestive system 
and physiology as a whole are geared to digesting and 
utilizing plant-based foods, which often have a medicinal 
value as well as providing sustenance. The dividing line between “foods” and “medicines” may  
not always be clear. Are lemons, papayas, onions, and oats 
foods or medicines? The answer, very simply, is that they  
are both. Lemon ( Citrus limon , p. 82) improves resistance  
to infection; papaya ( Carica papaya , p. 183) is taken in some 
parts of the world to expel worms; onion ( Allium cepa ,  
p. 164) relieves bronchial infections; and oats ( Avena sativa ,  
p. 175) support convalescence. Indeed, herbal medicine 
comes into its own when the distinctions between foods  
and medicines are removed. Cultivation of medicinal plants in Cameroon. Scientific research indicates that 
whole-plant preparations may often be gentler and more effective remedies 
than isolated plant chemicals.Ginkgo , one of the oldest known plant 
species, improves the circulation of blood  
to the head. US_010-013_How_Medicinal_Plants_work.indd   11 26/02/16   4:42 pm
12
The developmen T of herbal medicineThough we might eat a bowl of oatmeal oblivious to the 
medicinal benefits, it will, nonetheless, increase stamina, help the nervous system to function correctly, provide a good supply of B vitamins, and maintain regular bowel function. A similar range of benefits is provided by many of the other gentler-acting herbs listed in the Encyclopedia. Herbal Treatments
The strategies that herbal practitioners adopt to prevent illness or restore health in their patients are different in the many and varied herbal traditions across the planet, but  
the effects that herbal medicines have within the body to improve health do not vary. There are many thousands  
of medicinal plants in use throughout the world, with a tremendous range of actions and degrees of potency. Most have a specific action on particular body systems and are known to be suitable for treating certain types of ailments. See p. 13 for specific actions. Digestion, Respiration, & Circulation
Improving the quality of the diet is often an essential starting 
point in sustaining or regaining good health. The saying “Y ou are what you eat” is by and large true, though herbalists prefer to qualify it, saying “Y ou are what you absorb from what you eat.” Herbal medicines not only provide nutrients, but when needed they also strengthen and support the action of the digestive system, speeding up the rate of processing food and improving the absorption of nutrients. The body requires another kind of “nutrient” to  
function—oxygen. The lungs and respiratory system can  
be helped with herbs that relax the bronchial muscles and stimulate respiration. Once taken in by the body, nutrients and medicines are carried to the body’s estimated one hundred trillion cells. The circulatory system has a remarkable ability to adapt  
to an endlessly shifting pattern of demand. At rest, the flow  
of blood is mainly toward the center of the body, while when active, the muscles in the limbs make huge demands. Herbal medicines work to encourage circulation in particular ways. Some, for example, encourage blood to  
flow to the surface of the body; others stimulate the heart  to pump more efficiently; while others relax the muscles of the arteries, lowering blood pressure. Clearing Toxicity & Soothing Skin
After circulation has carried nutrients to the cells, waste 
matter must be removed. All too often in our polluted world, high levels of toxicity in the body are an underlying cause of  ill health, and herbalists use a wide range of cleansing herbs that improve the body’s ability to remove toxins. Perhaps  
the finest example of a detoxifying herb is burdock (Arctium lappa, p. 65), which is used extensively in both Western and Chinese medicine. Once herbs such as this reduce the toxic “load,” the body is able to invest greater resources  
in repairing and strengthening damaged tissue and  
weakened organs. The skin also plays an important role in good health. Antiseptic plants fight infection, while vulnerary (wound-healing) herbs such as comfrey (Symphytum officinale,  p. 138) encourage blood clotting and help speed the healing  of wounds. Nervous, Endocrine, & Immune Systems 
Good health depends on having a healthy, balanced nervous system. In order to ensure long-term good health of the nervous system, it is important to adapt well to life’s daily demands, to avoid excessive anxiety, worry, or depression, and to get sufficient rest and exercise. The latest research shows that the nervous system does not work in isolation but is complemented by the endocrine system, which controls the release of a whole symphony  
of hormones, including the sex hormones, which control fertility and often affect vitality and mood. The nervous system is also intimately linked with the immune system, which controls the ability to resist infection and to recover from illness and injury. This incredible complex of systems—part electrical, part chemical, part mechanical—must function harmoniously if good health is to be maintained. In health, the body has a seemingly infinite capacity, via its controlling systems, to adjust and change to external pressures. This ability to adapt to the external world while the body’s internal workings remain constant is known as homeostasis. Many herbs work with  the immune, nervous, and endocrine systems to help the body adapt more effectively to stresses and strains of all kinds: physical, mental, emotional, and even spiritual. They are effective because they work in tune with the body’s processes. Some herbs are adaptogenic, meaning that they have an ability to help people to adapt, either by supporting the nervous system and easing nervous and emotional tension,  or by working directly with the body’s own physiological processes to maintain health. The prime example of an adaptogenic herb is ginseng (Panax ginseng, p. 118), which  is an effective remedy at times of great mental or physical stress, but in certain cases can also be taken when a relaxing effect is required, for example to relieve headaches, or to ensure a good night’s sleep. Complex Natural Medicines
As can be seen, an herb is not a “magic bullet” with a single 
action, but a complex natural medicine composed of many active constituents that work on different body systems. By combining scientific research into active constituents with clinical observation and traditional knowledge of the whole plant, we can develop a rounded picture of each herb’s range of medicinal uses. US_010-013_How_Medicinal_Plants_work.indd   12 26/02/16   4:42 pm13 How Medicinal Plants workNervous system
Nervines,  e.g., rosemary ( Rosmarinus  
officinalis , p. 128), support and strengthen  
the nervous system. Relaxants,  e.g., lemon 
balm ( Melissa officinalis , p. 113), relax the 
nervous system. Sedatives,  e.g., mistletoe ( Viscum 
album , p. 283), reduce nervous activity. Stimulants,  
e.g., kola nut ( Cola acuminata , p. 192), increase 
nervous activity. Tonics,  e.g., oats ( Avena  sativa ,  
p. 175), improve nerve function and tone, and 
help to restore the nervous system as a whole. Circulation & heart
Cardiotonics,  e.g., dan shen  (Salvia  miltiorrhiza ,  
p. 130), vary in action. Some slow heartbeat 
rate, while others increase it. Some improve 
the regularity and strength of the heart’s 
contractions. Circulatory stimulants,  e.g., cayenne 
(Capsicum  frutescens , p. 74), improve the 
circulation of blood to the extremities. Diaphoretics,  e.g., ju hua (Chrysanthemum  x 
morifolium , p. 78), encourage blood flow to  
the surface of the body, promote sweating, and 
lower blood pressure. Spasmolytics,  e.g., cramp 
bark ( Viburnum opulus , p. 150), relax the muscles, 
helping to lower blood pressure. Digestive organs
Antiseptics,  e.g., ginger ( Zingiber officinale , p. 155), protect 
against infection. Astringents, e.g., bistort ( Polygonum 
bistorta , p. 253), tighten up the inner lining of the intestines 
and create a protective coating over them. Bitters,  e.g., 
wormwood ( Artemisia absinthium , p. 66), 
stimulate secretion of digestive 
juices by the stomach and 
intestines. Carminatives,  e.g., 
sweet flag ( Acorus calamus ,  
p. 57), relieve gas and cramps. Cholagogues,  e.g, fringe tree 
(Chionanthus virginicus ,  
p. 188), improve the flow of bile into 
the intestines. Choleretics,  e.g., artichoke ( Cynara scolymus ,  
p. 199), stimulate secretion of bile by the liver. Demulcents,  
e.g., psyllium ( Plantago  spp., p. 123), soothe the digestive 
system and protect against acidity and irritation. Hepatics,  e.g., bupleurum ( Bupleurum chinense ,  
p. 72), prevent liver damage. Laxatives,   
e.g., senna  (Cassia senna , p. 75), 
stimulate bowel movements. Stomachics,  e.g., cardamom  
(Eletteria cardamomum , p. 93), 
protect and support  
the stomach.Musculoskeletal system
Analgesics,  e.g., yellow jasmine ( Gelsemium empervirens , 
p. 216), relieve joint and nerve pain. Anti-
inflammatories,  e.g., white willow ( Salix alba , p. 129), 
reduce swelling and pain in joints. Antispasmodics,  e.g., 
cinchona ( Cinchona  spp., p. 80), relax tense 
and cramped muscles.Urinary system
Antiseptics , e.g., buchu ( Barosma betulina , p. 71), 
disinfect the urinary tubules. Astringents,  e.g., 
horsetail ( Equisetum arvense , p. 205), tighten and 
protect the urinary tubules. Diuretics,  e.g. cornsilk 
(Zea mays , p. 154), stimulate the flow of urine.Endocrine glands
Adaptogens,  e.g., ginseng ( Panax ginseng ,  
p. 118), help the body adjust to external pressures 
and stress. Hormonally active herbs,  e.g., chaste tree 
(Vitex agnus-castus , p. 151), stimulate production of 
sex and other hormones. Emmenagogues,  e.g., 
black cohosh ( Cimicifuga racemosa , p. 79), 
encourage or regulate menstruation.Respiratory system
Antiseptics and antibiotics,  e.g., garlic ( Allium 
sativum , p. 59), help the lungs resist infection. Expectorants,  e.g., elecampane ( Inula helenium ,  
p. 107), stimulate the coughing up of mucus. Demulcents,  e.g., coltsfoot ( Tussilago farfara ,  
p. 278), soothe irritated membranes. Spasmolytics,  e.g., visnaga ( Ammi visnaga , p. 62), 
relax bronchial muscles.Immune system
Immune modulators,  e.g., echinacea ( Echinacea  
spp. p. 92) and pau d’arco ( Tabebuia  spp.,  
p. 139), encourage the immune system to 
ward off infection. Skin
Antiseptics,  e.g., tea tree ( Melaleuca alternifolia , p. 112), 
disinfect the skin. Emollients,  e.g., marshmallow 
(Althea officinalis , p. 165), reduce itchiness, redness, 
and soreness. Astringents, e.g., witch hazel 
(Hamamelis virginiana , p. 102), tighten the skin. Depuratives,  e.g., burdock ( Arctium lappa , p. 65), 
encourage removal of waste products. Healing and 
vulnerary herbs,  e.g., comfrey ( Symphytum officinale ,  
p. 138) and calendula ( Calendula officinalis , p. 73), aid 
the healing of cuts, wounds, and abrasions.Herbs & Body Systems
One of the most common ways of classifying medicinal plants is to identify their actions, for example whether they are 
sedative, antiseptic, or diuretic, and the degree to which they affect different body systems. Herbs often have a pronounced 
action on a particular body system, for example a plant that is strongly antiseptic in the digestive tract may be less so in the 
respiratory tract. Examples of how herbs work on the body are given below. Calendula
(Calendula officinalis)
Cayenne
(Capsicum frutescens)
Sweet Flag
(Acorus calamus)Garlic
(Allium sativum)
Ginseng
(Panax ginseng)Echinacea
(Echinacea spp.) Cornsilk
(Zea mays)
White Willow
(Salix alba)Rosemary
(Rosmarinus officinalis)
Senna
(Cassia senna)
US_010-013_How_Medicinal_Plants_work.indd   13 26/02/16   4:42 pm
14
The developmen T of herbal medicinePhenols
Phenols are a very varied group  
of plant constituents ranging from 
salicylic acid, a molecule similar  
to aspirin (acetylsalicylic acid), to complex sugar-containing phenolic glycosides. Phenols are often anti-inflammatory and antiseptic, and  
are thought to be produced by plants to protect against infection  and feeding by insects. Phenolic acids, such as rosmarinic acid,  
are strongly antioxidant and anti-inflammatory, and can also have antiviral properties. Wintergreen (Gaultheria procumbens, p. 215)  
and white willow (Salix alba, p. 129) both contain salicylates. Many mint family members contain phenols—for example, the strongly antiseptic thymol, found in thyme (Thymus vulgaris, p. 143). Volatile Oils
Volatile oils—which are extracted  
from plants to produce essential oils—are some  
of the most important medicinally active plant constituents, and are  also used widely in perfumery. They are complex mixtures often of 100 or more compounds, mostly made up of monoterpenes—molecules containing 10 carbon atoms. Essential oils have many uses. Tea tree oil (Melaleuca alternifolia, p. 112) is strongly antiseptic, while sweet gale oil (Myrica gale, p. 238) is an effective insect repellent. On distillation, some essential oils contain compounds not found in the volatile oil—chamazulene, found in German chamomile (Chamomilla recutita, p. 77) essential oil, is anti-inflammatory and antiallergenic. Resins—sticky oily substances that seep from plants, for example from the bark of Scots  
pine (Pinus sylvestris, p. 249)—are often  
linked with essential oils (oleoresins) and  
gums (see Polysaccharides), though they  
are nonvolatile. Active Constituents
The medicinal effects of certain plants are well known. German chamomile, for example, has been 
taken to soothe digestive problems for thousands of years, and aloe vera was known to Cleopatra as  a healing skin remedy. It is only relatively recently, however, that active constituents responsible for the medicinal actions of plants have been isolated and observed. Knowing a little about the chemicals contained in plants helps you to understand how they work within the body. Flavonoids
Found widely throughout 
the plant world, flavonoids are polyphenolic compounds that act  as pigments, imparting color, often yellow or white, to flowers and fruits. They have a wide range of actions and many medicinal uses. They are antioxidant and especially useful in maintaining healthy circulation. Some flavonoids also have anti-inflammatory, antiviral, and liver-protective activity. Flavonoids such as hesperidin and rutin, found in many plants, notably buckwheat (Fagopyrum esculentum,  p. 210) and lemon ( Citrus limon, p. 82), strengthen capillaries  
and prevent leakage into surrounding tissues. Isoflavones,  found for example in red clover ( Trifolium pratense,  
p. 277), are estrogenic and valuable in treating  
menopausal symptoms. Tannins
T annins are produced to a greater or lesser degree by all plants. The harsh, astringent taste of tannin-laden bark and leaves makes them unpalatable to insects and grazing animals. T annins are polyphenolic compounds that contract and astringe tissues of the body by binding with and precipitating proteins—hence their use to “tan” leather. They also help to stop bleeding and to check infection. T annin-containing herbs are used to tighten up over-relaxed tissues—as in varicose veins—to dry up excessive watery secretions—as in diarrhea—and to protect damaged tissue—such as skin problems resulting from eczema or a burn. Oak bark (Quercus robur, p. 260) and black catechu (Acacia catechu, p. 158) are both high in tannins.Black Catechu
(Acacia catechu)Thyme
(Thymus vulgaris)Lemon
(Citrus limon)
German Chamomile
(Chamomilla recutita)
US_014-017_Active_Constituents.indd   14 26/02/16   4:42 pm15 Active constituentsProanthocyanins
Closely related to tannins and flavonoids, 
these polyphenolic compounds are 
pigments that give flowers and 
fruits a blue, purple, or red hue. They are powerfully antioxidant 
and free-radical scavengers. They 
protect the circulation from damage, 
especially the circulation in the 
heart, hands, feet, and eyes. Blackberry ( Rubus fruticosus , 
p. 264), red grapes ( Vitis 
vinifera , p. 283), and 
hawthorn ( Crataegus 
oxycantha , p. 87) all contain 
appreciable quantities of 
these proanthocyanins. Coumarins
Coumarins of different kinds are found  
in many plant species and have widely 
divergent actions. The coumarins in melilot 
(Melilotus officinalis , p. 234) and horse 
chestnut ( Aesculus hippocastanum , p. 58)  
help to keep the blood thin, while 
furanocoumarins such as bergapten,  
found in celery ( Apium graveolens , p. 64), 
stimulate skin tanning, and khellin, found  
in visnaga ( Ammi visnaga , p. 62), is a 
powerful smooth-muscle relaxant. Saponins
The main active 
constituents in many 
key medicinal plants, 
saponins gained their 
name because, like soap, 
they make a lather when 
placed in water. Saponins occur in two 
different forms—steroidal and triterpenoid. The chemical structure of steroidal saponins 
is similar to that of many of the body’s hormones, for example 
estrogen and cortisol, and many plants containing them have a 
marked hormonal activity. Wild yam ( Dioscorea villosa , p. 91), from  
which the contraceptive pill was first developed, contains steroidal 
saponins. Triterpenoid saponins occur more commonly—for example  
in licorice ( Glycyrrhiza glabra , p. 101) and cowslip root ( Primula veris ,  
p. 256)—but have less hormonal activity. They are often expectorant  
and aid absorption of nutrients.Anthraquinones
Anthraquinones are the main active 
constituents in herbs such as senna 
(Cassia senna , p. 75) and Chinese rhubarb 
(Rheum palmatum , p. 126), both of which 
are taken to relieve constipation. Anthraquinones have an irritant laxative 
effect on the large intestine, causing 
contractions of the intestinal walls 
and stimulating a bowel 
movement approximately 10 
hours after being taken. They 
also make the stool more liquid, 
easing bowel movements. Cyanogenic glycosides
Though these glycosides are 
based on cyanide, a very 
potent poison, in small 
doses they have a 
helpful sedative and 
relaxant effect  
on the heart and 
muscles. The bark  
of wild cherry ( Prunus 
serotina , p. 257) and the 
leaves of elder ( Sambucus nigra ,  
p. 132) both contain cyanogenic 
glycosides, which contribute to the plant’s 
ability to suppress and soothe irritant dry 
coughs. Many fruit kernels contain high 
levels of cyanogenic glycosides, for example 
those of apricot ( Prunus armeniaca , p. 257).Cardiac Glycosides
Found in various medicinal plants, notably  
in foxgloves (see common foxglove, Digitalis 
purpurea , p. 202) and in lily of the valley 
(Convallaria majalis , p. 194), cardiac glycosides 
such as digitoxin, digoxin, and convallotoxin 
have a strong, direct action on the heart, 
supporting its strength and rate of 
contraction when it is failing. Cardiac 
glycosides are also significantly diuretic. They help to stimulate urine production, 
thus increasing the removal of fluid from 
the tissues and circulatory system. Celery
(Apium graveolens)Chinese Rhubarb
(Rheum palmatum)
Blackberry
(Rubus fruticosus)
Licorice
(Glycyrrhiza 
glabra)Common Foxglove
(Digitalis purpurea)
Elderflower
(Sambucus nigra)
US_014-017_Active_Constituents.indd   15 26/02/16   4:42 pm
16
The developmen T of herbal medicinePolysaccharides
Found in all plants, polysaccharides 
are multiple units of sugar molecules linked together. From  
an herbal point of view, the most important polysaccharides are the “sticky” mucilages and gums, which are commonly found in roots, bark, leaves, and seeds. Both mucilage and gum soak up large quantities of water, producing a sticky, jelly-like mass that can be used to soothe and protect irritated tissue, for example, dry irritated skin and sore or inflamed mucous membranes  
in the gut. Mucilaginous herbs, such as slippery elm (Ulmus rubra, p. 145) and linseed or flaxseed (Linum usitatissimum, p. 109), are best prepared  by soaking (macerating) in plenty of cold water. Some polysaccharides stimulate the immune system, for example acemannan, which is found  
in the leaves of aloe vera (Aloe vera, p. 60).Alkaloids
A very mixed group, alkaloids mostly contain a nitrogen-bearing molecule  (-NH
2) that makes them particularly 
pharmacologically active. Some are well-known drugs and have a recognized medical use. Vincristine, for example, derived from Madagascar periwinkle (Vinca rosea, p. 282), is used to treat some types of cancer. Other alkaloids, such as atropine, found in deadly nightshade (Atropa belladonna,  p. 69), have a direct effect on the body, reducing spasms, relieving pain,  
and drying up bodily secretions. Vitamins
Though often overlooked, many medicinal plants contain useful levels of vitamins. Some are well known for their vitamin content, for example dog rose (Rosa canina, p. 263) has high levels of vitamin C, and carrot (Daucus carota , p. 201) is rich in beta-
carotene (pro-vitamin A), but many are less well recognized. Watercress ( Nasturtium 
officinale, p. 239), for 
example, contains 
appreciable levels of 
vitamins B
1, B2, C, and E as well 
as beta-carotene, while sea 
buckthorn (Hippophae rhamnoides, p. 220) can be regarded as a vitamin and mineral supplement in its  
own right.Glucosilinates
Found exclusively in species of  the mustard and cabbage family, glucosilinates have an irritant effect  on the skin, causing inflammation and blistering. Applied as poultices to painful or aching joints, they increase blood flow to the affected area, helping to remove the buildup of waste products (a contributory factor in many joint problems). On eating, glucosilinates are broken down and produce a strong, pungent taste. Radish (Raphanus sativus, p. 261)  and watercress (Nasturtium officinale,  p. 239) are typical glucosilinate-containing plants. Bitters
Bitters are a varied group of constituents linked only by their pronounced bitter taste. The bitterness itself stimulates secretions  
by the salivary glands and digestive organs. Such secretions can dramatically improve the appetite and strengthen the overall function  
of the digestive system. With the improved digestion and absorption of nutrients that follow, the body is nourished and strengthened. Many  herbs have bitter constituents, notably wormwood (Artemisia absinthium, p. 66),  
chiretta (Swertia chirata, p. 273), and hops (Humulus lupulus, p. 104). Minerals
Like vegetable foods, many medicinal plants provide high levels of minerals. Plants, especially organically grown  
ones, draw minerals from the soil and convert them into a form that is more easily absorbed and used by the body. Whether plants are eaten as a vegetable, like cabbage (Brassica oleracea, p. 180), or taken as a medicine, like bladderwrack (Fucus vesiculosus,  p. 213), in many cases the mineral content is a key factor in the plant’s therapeutic activity within the body. Dandelion leaf (Taraxacum officinale, p. 141) is a potent diuretic, balanced by its high potassium  content, while the high silica content of horsetail (Equisetum arvense, p. 205) supports the repair 
of connective tissue, making it useful in arthritis. Slippery Elm
(Ulmus rubra)
Deadly Nightshade
(Atropa belladonna)
Dog Rose
(Rosa canina)
Dandelion
(Taraxacum officinale)Radish
(Raphanus sativus)
Wormwood(Artemisia absinthium)
US_014-017_Active_Constituents.indd   16 26/02/16   4:42 pm17 quality control
CalendulaWhat should you look for when buying herbal medicines? It is usually most convenient to buy capsules, tablets, 
essential oils, pessaries, and perhaps tinctures, and to 
make up your own infusions, decoctions, and syrups  
(see p. 291 and p. 293). • Buy from a reputable herb store, staffed by 
people knowledgeable about herbal medicines. • Only buy herbs online from established  
herbal suppliers. • Buy organic herbs and products where available. Buying Dried Herbs
Dried herbs are generally available from herbal suppliers. Buying  
from shops is preferable to buying online because the herbs can be 
examined before purchasing. However, it is possible some online 
companies may supply fresher herbs due to higher turnover. To gain the 
best medicinal effect, good-quality produce is essential. Shop around 
and bear in mind the following points before buying:
• Herbs should not be stored in clear glass jars or in direct sunlight,  
as this causes oxidation, which affects their efficacy.• Good-quality aromatic herbs should have a distinct scent and taste. • Check for signs of infestation due to poor drying techniques, or 
adulteration. This can sometimes be recognized by the presence of  
dried grass or other non-medicinal material in the jar. • Herbs lose their color as they age. Look for bright material that has 
been well dried and stored, and that is not too old. Calendula flowers 
(Calendula officinalis , p. 73) that are a vivid yellow/orange color are likely 
to make good medicine. If they have been sitting on a shelf for  
18 months, they will probably look drab and pale. Buying Herbal Products
When buying products such as capsules, tablets, essential oils, 
pessaries, and tinctures, always check the label on the jar or packet. If it does not do the following, do not buy it:
■ Name all constituents of the product
■ State the recommended daily dosage
■ State the weight of each capsule or tablet, or volume of bottle
■ List the weight of each constituent of a capsule, tablet, etc. ■ List the ratio of herb in the product (for example, 1:3, meaning  
1 part herb to 3 parts liquid).Quality is vital for herbal medicine. Without a guarantee that 
the correct herb of the right quality is being used, it is hard to 
be confident that the medicine will prove effective. In fact, one 
reason why the medical profession has generally preferred 
conventional medicines to herbal ones is the difficulty of 
guaranteeing quality in herbal remedies. Many herbal products 
on the market are of high quality but some can be very poor. A 2006 U.S. study of black cohosh ( Cimicifuga racemosa , p. 79) 
found that only 7 out of 11 over-the-counter products tested 
contained what was stated on the label. Four contained a 
cheaper Chinese species instead. The adulteration of herbal 
products, particularly in Chinese and Indian herbs sold in 
the West is, regrettably, not unusual. Herb quality may be affected not only by deliberate 
adulteration, but by the use of wrongly identified or poor-quality 
material. The herb may have been poorly harvested, dried, or 
stored, or it may be old or decayed. It may even be that the 
wrong herb was used. In each case, the lack of attention to 
quality results in a product with reduced medicinal value—
or even none at all. To try to ensure that only good-quality products are made, 
manufacturers of genuine herbal medicines use strict quality-control procedures. Usually this involves comparing the dried 
herb material with listings in an herbal or national pharmacopeia 
(a standard reference work that gives the characteristics one 
would expect to find when analyzing a specific herb). Quality 
control involves making routine checks to establish that the 
herbal material is what it claims to be and that it meets a number 
of minimum requirements. The material is inspected with the 
naked eye, and assessed microscopically, to see if its botanical 
profile matches the standard. Other checks are made to see 
whether it contains appropriate levels of active constituents 
and to ensure that the material is free from contamination. More sensitive quality-control methods, however, recognize 
that the quality of an herb does not depend simply on the 
presence of one or two key active constituents. Increasingly, 
people in the world of herbal medicine are focusing on the 
“fingerprint” of an herb—the unique chemical profile that 
represents the complex pattern of constituents found when 
good-quality dried herb material is analyzed by sensitive 
scientific machinery. By monitoring the sample and comparing 
it with this unique fingerprint, it is possible to make a much 
broader assessment of quality than when using only one or 
two constituents as a standard.Quality control
Making the most of herbal medicine means ensuring that herbs and herbal products  
used are of good quality—properly grown, well dried, correctly processed, and within  
their sell-by date. Using poor-quality herbal produce is all too often a waste of money 
since there is the strong possibility that you will receive little benefit from it. When it 
comes to herbal medicine, quality is everything. Buying Herbal Medicines
US_014-017_Active_Constituents.indd   17 26/02/16   4:42 pm
18
The developmen T of herbal medicineEarly Origins to the 19th Century
In an age of medical specialization in which an expert in neurology will know little about  
the latest developments in medicine for the ear, nose, and throat, it is difficult to imagine the 
practices of an earlier time, when healing was holistic in nature and heavily reliant on magic, mysticism, and age-old oral traditions. From the earliest times, medicinal plants have been crucial in 
sustaining the health and the well-being of mankind. Flaxseed (Linum usitatissimum, p. 109), for example, provided its 
harvesters with a nutritious food oil, fuel, a cosmetic balm  
for the skin, and fiber to make fabric. At the same time it  
was used to treat conditions such as bronchitis, respiratory congestion, boils, and a number of digestive problems. Given  the life-enhancing benefits that this and so many other plants conferred, it is hardly surprising that most cultures believed them to have magical as well as medicinal abilities. It is reasonable to assume that for tens of thousands of years herbs were probably used as much for their ritual magical powers as for their medicinal qualities. A 60,000-year-old burial site excavated in Iraq, for instance, was found to contain eight different medicinal plants, including ephedra (Ephedra sinica, p. 95). The inclusion of the plants in the  
tomb suggests they had supernatural significance as well  
as medicinal value. In some cultures, plants were considered to have souls. Even Aristotle, the 4th-century bce Greek philosopher, thought that plants had a “psyche,” albeit of a lesser order than the human soul. In Hinduism, which dates back  
to at least 1500 bce, many plants are sacred to specific divinities. For example, the bael tree (Aegle marmelos,  p. 161) is said to shelter Shiva, the god of health, beneath  its branches. In medieval Europe, the Doctrine of Signatures stated 
there was a connection between how a plant looked—  
God’s “signature”—and how it might be used medicinally. For example, the mottled leaves of lungwort (Pulmonaria officinalis, p. 259) were thought to resemble lung tissue,  
and the plant is still used to treat ailments of the  
respiratory tract. Even in Western cultures, beliefs in plant spirits linger. Until 
the first half of the 20th century, British farm workers would not cut down elder trees (Sambucus nigra, p. 132) for fear of arousing the anger of the Elder Mother, the spirit who lived in and protected the tree. In a similar vein, native peoples of the Andes in South 
America believe that the coca plant (Erythroxylum coca,  p. 206) is protected by Mama Coca, a spirit who must be respected and placated if the leaves are to be harvested  
and used. Shamanistic Medicine
In many traditional societies today, the world is believed to  be shaped by good and evil spirits. In these societies, illness  is thought to stem from malignant forces or possession by  evil spirits. If a member of the tribe falls ill, the shaman (the “medicine” man or woman) is expected to intercede with the spirit world to bring about a cure. Shamans often enter the spiritual realm with the aid of hallucinogenic plants or fungi, such as ayahuasca (Banisteriopsis caapi, p. 176), taken  by Amazonian shamans, or fly agaric (Amanita muscaria), taken by traditional healers of the Siberian steppes. At the same time, the shaman provides medical treatment 
for the physical needs of the patient—putting salves and compresses on wounds, boiling up decoctions and barks  
for internal treatment, stimulating sweating for fevers, and so 
Mistletoe, which the Druids called “golden bough,” had a central place in their 
shamanistic religious and healing ceremonies. The Druids had a well-developed knowledge of medicinal plants. US_018-027_Early_Origins_To_The_19_Century.indd   18 26/02/16   4:42 pm19 Early Origins t O th E 19th C Entury
on. Such treatment is based on a wealth of acutely observed 
plant lore and knowledge, handed down in an oral tradition 
from generation to generation. The Development of Medicinal Lore
It is generally recognized that our ancestors had a wide range 
of medicinal plants at their disposal, and that they likewise 
possessed a profound understanding of plants’ healing powers. In fact, up until the 20th century, every village and rural 
community had a wealth of herbal folklore. Tried and tested 
local plants were picked for a range of common health 
problems and taken as teas, applied as lotions, or even mixed 
with lard and rubbed in as an ointment. But what were the origins of this herbal expertise? There 
are no definitive answers. Clearly, acute observation coupled 
with trial and error has played a predominant role. Human 
societies have had many thousands of years to observe the 
effects—both good and bad—of eating a particular root,  
leaf, or berry. Watching the behavior of animals after they 
have eaten or rubbed against certain plants has also added  
to medicinal lore. If one watches sheep or cattle, they almost 
unerringly steer a path past poisonous plants such as ragwort (Senecio jacobaea ) or oleander ( Nerium oleander ). Over and 
above such close observation, some people have speculated 
that human beings, like grazing animals, have an instinct that 
recognizes poisonous as opposed to medicinal plants. Ancient Civilizations
As civilizations grew from 3000 bce 
onward in Egypt, the Middle East, 
India, and China, so the use of 
herbs became more sophisticated, 
and the first written accounts of 
medicinal plants were made. The 
Egyptian Ebers papyrus of c. 1500 
bce is the earliest surviving 
example. It lists dozens of 
medicinal plants, their uses, and 
related spells and incantations. The 
herbs include myrrh ( Commiphora molmol , p. 85), castor oil  
(Ricinus communis , p. 262), and garlic ( Allium sativum , p. 59). In India, the Vedas , epic poems written c. 1500 bce, also 
contain rich material on the herbal lore of that time. The 
Vedas  were followed in about 400 bce by the Charaka Samhita , 
written by the physician Charaka. This medical treatise 
includes details of around 350 herbal medicines. Among 
them are visnaga ( Ammi visnaga , p. 62), an herb of Middle 
Eastern origin that has recently proven effective in the 
treatment of asthma, and gotu kola ( Centella asiatica , p. 76), 
which has long been used to treat leprosy. Medicine Breaks from its  
Mystical Origins
By about 500 bce in developed 
cultures, medicine began to separate 
from the magical and spiritual 
world. Hippocrates (460–377 bce), 
the Greek “father of medicine,” 
considered illness to be a natural 
rather than a supernatural 
phenomenon, and he felt that 
medicine should be given without 
ritual ceremonies or magic. In the earliest Chinese medical  
text, the Yellow Emperor’s Classic of 
Internal Medicine  written in the 1st 
century bce, the emphasis on rational 
medicine is equally clear: “In treating 
illness, it is necessary to examine  
the entire context, scrutinize the Shiva , the Hindu god who oversees health, is traditionally thought to live under the bael tree, 
an important medicinal plant in India. The bump  in the right cheek of this 
Peruvian figurine may represent 
coca, taken in that country to 
increase endurance.Castor oil plant  
has been used 
medicinally for 
about 4000 years. US_018-027_Early_Origins_To_The_19_Century.indd   19 26/02/16   4:42 pm
20
The developmen T of herbal medicinesymptoms, observe the emotions and attitudes. If one  
insists on the presence of ghosts and spirits one cannot  speak of therapeutics.”
Foundation of Major Herbal Traditions  
300 bce–600 ce
Trade between Europe, the Middle East, India, and Asia was 
already well under way by the 2nd century bce, and trade routes became established for many medicinal and culinary herbs. Cloves (Eugenia caryophyllata, p. 97), for example, which are native to the Philippines and the Molucca Islands near New Guinea, were imported into China in the 3rd century bce, and first arrived in Egypt around 176 ce. As the centuries passed, the popularity of cloves grew, and by the 8th century ce, their strong aromatic flavor and powerfully antiseptic and analgesic properties were familiar throughout most of Europe. As trade and interest in 
herbal medicines and spices flourished, various writers tried to make systematic records of plants with a known medicinal action and record their properties. In China, the Divine 
Husbandman’s Classic  
(Shen’nong Bencaojing), written in the 1st century ce, has 364 entries, of which 252 are herbal medicines, including bupleurum ( Bupleurum 
chinense, p. 72), coltsfoot (Tussilago farfara,  
p. 278), and gan cao ( Glycyrrhiza uralensis). This Daoist text  
laid the foundations for the continuous development  
and refinement of Chinese herbal medicine up to the  
present day. In Europe, a 1st-century ce Greek physician named Dioscorides wrote the first European herbal, De Materia Medica. His intention was to produce an accurate and authoritative work on herbal medicines, and in this he was dramatically successful. Among the many plants mentioned are juniper (Juniperus communis, p. 224), elm (Ulmus carpinifolia), peony (Paeonia officinalis, p. 243), and burdock (Arctium lappa, p. 65). The text, listing about 600 herbs in all, was to have  
an astonishing influence on Western medicine, being the principal reference used in Europe until the 17th century. It was translated into languages as varied as Anglo-Saxon, Persian, and Hebrew. In 512 ce, De Materia Medica became the first herbal to feature pictures of the plants discussed. Made for Juliana Arnicia, the daughter of the Roman emperor Flavius Avicius Olybrius, it contained nearly 400 full-page color illustrations. Galen (131–200 ce), physician to the Roman emperor  
Marcus Aurelius, had an equally profound influence on the development of herbal medicine. Galen drew inspiration from Hippocrates and based his theories on the “theory  of the four humors” (see p. 32). His ideas shaped and, some would say, distorted medical practice for the next 1,400 years. In India and in China, elaborate medical systems somewhat resembling the theory of the four humors developed (see  
pp. 36–38 and pp. 40–41 respectively) that have endured to the present day. Though European, Indian, and Chinese systems differ 
widely, they all consider that imbalance within the constituent elements of the body is the cause of illness, and that the aim of the healer is to restore balance, often with the aid of herbal remedies. Folk Healing in the Middle Ages
The theories of Galenic, Ayurvedic (Indian), and Chinese traditional medicine, however, would have meant practically nothing to most of the world’s population. As is still the case today for some indigenous peoples who have little access  
to conventional medicines, in the past most villages and communities relied on the services of local “wise” men and women for medical treatment. These healers were almost certainly ignorant of the conventions of scholastic medicine, yet through apprenticeship and practice in treating illness, attending childbirth, and making use of locally growing herbs as a natural pharmacy, they developed a high level of practical medical knowledge. Galen’s “four humors,” which he believed 
made up the human constitution.Frontispiece decoration for the first illustrated herbal, Dioscorides’ De Materia Medica, produced in Constantinople in 512 ce. US_018-027_Early_Origins_To_The_19_Century.indd   20 26/02/16   4:42 pm21 Early Origins t O th E 19th C EnturyWe tend to underestimate the medical skills of apparently 
undeveloped communities—particularly during the so-called 
Dark Ages in medieval Europe—but it is evident that many 
people had a surprisingly sophisticated understanding of plant 
medicine. For example, recent excavations at an 11th-century 
monastic hospital in Scotland revealed that the monks were 
using exotic herbs such as opium poppy ( Papaver somniferum , 
p. 244) and marijuana ( Cannabis sativa , p. 182) as painkillers and 
anesthetics. Likewise, the herbalists in Myddfai, a village in 
South Wales, obviously knew of Hippocrates’ writings in the 
6th century ce and used a wide variety of medicinal plants. The texts that have been handed down from that herbal 
tradition are filled with an engaging blend of superstition and 
wisdom. Two prescriptions from a 13th-century manuscript 
illustrate the point. The first recipe could have been written by 
a modern, scientifically trained herbalist; the second, one must 
presume, is pure fancy, and would not choose to try it out! To Strengthen the Sight
Take Eyebright and Red Fennel, a handful of each, and half a handful  
of Rue, distil, and wash your eye daily therewith . To Destroy a Worm in the Tooth
Take the root of a cat’s ear, bruise, and apply to the patient’s tooth  
for three nights, and it will kill the worm. Islamic & Indian Medicine 500–1500 ce
Folk medicine was largely unaffected by sweeping forces of 
history, but Western scholastic medicine suffered greatly with 
the decline of the Roman Empire. It was thanks to the flowering of Arabic culture in  
500–1300 ce  that the gains of the classical Greek and Roman period were preserved and elaborated. The spread 
of Islamic culture along North Africa and into present-day  
Italy, Spain, and Portugal led to the founding of renowned 
medical schools, notably at Cordoba in Spain. The Arabs 
were expert pharmacists, blending and mixing herbs to 
improve their medicinal effect and their taste. Their 
contacts with both Indian and Chinese medical traditions 
meant that they had a remarkable range of medical and 
herbal knowledge to draw on and develop. Avicenna  
(980–1037 ce ), author of Canon of Medicine , was the  
most famous physician of the day, but perhaps the most 
unusual herbal connection was made a century before  
his time by Ibn Cordoba, an intrepid Arab seafarer, who 
brought ginseng root ( Panax ginseng , p. 118) from China  
to Europe. This valuable tonic herb was to be regularly 
imported into Europe from the 16th century onward. Further east, in India, the 7th century saw a golden age  
of medicine. Thousands of students studied Ayurveda at 
university, especially at Nalanda. There, scholars recorded  
the medical achievements of the time, with advances such 
as the development of hospitals, maternity homes, and the 
planting of medicinal herb gardens. Central & South American Cures
On the other side of the world, the ancient civilizations  
of Central and South America—Maya, Aztec, and Inca—  
all had herbal traditions with a profound understanding  
of local medicinal plants. One account tells of Incas taking 
local herbalists from what is now Bolivia back to their  
capital Cuzco in Peru because of the herbalists’ great 
capabilities, which reputedly included growing penicillin  
on green banana skins. At the same time, medicine and religion were still closely 
interwoven in these cultures, possibly even more so than  
in Europe. One gruesome account tells of Aztec sufferers  
of skin diseases who sought to appease the god Xipe  
Totec by wearing the flayed skins of sacrificial victims. Fortunately, a supernatural appeal to the gods  
was not the sole means to relieve this and  
other afflictions. Many herbs were available  
as alternative treatments, including 
sarsaparilla ( Smilax  spp., p. 270), a tonic  
and cleansing herb that was used  
in treatments for a variety of skin 
complaints including eczema  
and psoriasis. Galen and Hippocrates , two of the  
preeminent physicians of the classical  
era, debate in this imaginary scene 
depicted in a fresco.
Encyclopedia_Of_Herbal_Medicine.txt
Summarize the following text section accurately and concisely. Maintain specific details and numerical information, and use anti-repetition mechanisms:

        HERBAL
MEDICINEENCYCLOPEDIA OF
US_001_003_Half_Full_title. indd   1 26/02/16   4:42 pm
US_001_003_Half_Full_title. indd   2 26/02/16   4:42 pmHERBAL
MEDICINEENCYCLOPEDIA OF
Andrew chevallier
fnimh
US_001_003_Half_Full_title. indd   3 26/02/16   4:42 pm
 
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IMPORTANT NOTICE 
Do not try self-diagnosis or attempt self-treatment for serious or long-term problems without first consulting 
a qualified medical herbalist or medical practitioner as appropriate. Do not take any herb without first 
checking the cautions in the relevant herb entry (see  pp. 56–283) and the Essential Information on  
pp. 298–299. Do not exceed any dosages recommended. Always consult a professional practitioner if 
symptoms persist. If taking prescribed medicines, seek professional medical advice before using herbal 
remedies. T ake care to correctly identify plants and do not harvest restricted or banned species. So far as the 
author is aware, the information given is correct and up to date as of July 2016. Practice, laws, and regulations 
all change, and the reader should obtain up-to-date professional advice on any such issues. In addition, this 
book contains general information on growing cannabis, which is a controlled substance in North America 
and throughout much of the world. As the use and cultivation of cannabis and its derivative products can 
carry heavy penalties, you should research your local laws before using the information in this book. The 
author and the publisher expressly disclaim any liability, loss, or risk, personal or otherwise, which is incurred 
as a consequence, directly or indirectly, of the use and application of any of the contents of this book. Third American Edition, 2016
First American Edition, 1996
This edition published in the United States in 2016 by  
DK Publishing, 345 Hudson Street, New Y ork, New Y ork 10014
Copyright © 1996, 2001, 2016 Dorling Kindersley Limited
Text copyright © 1996, 2001, 2016 Andrew Chevallier 
DK, a Division of Penguin Random House LLC 
16  17  18  19  20  10  9  8  7  6  5  4  3  2  1
001–285452–July/2016
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stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical,  
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FIRST EDITION
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US_004-005_Imprint_Contents. indd   4 26/02/16   4:42 pmContents
Introduction
THE DEVELOPMENT OF HERBAL MEDICINE
How Medicinal Plants Work
Active Constituents
Quality Control
Early Origins to the 19th Century
20th Century Onward
Herbal Traditions of the World  
Europe  
India and the Middle East  
China, Japan, and Southeast Asia 
Africa  
Australia and New Zealand 
North America  
South America
KEY MEDICINAL PLANTS
A visual guide to 1 00 key herbs from around the world with
details of their habitat, constituents, actions, traditional
and current uses, and information on the latest research. Also included are key preparations and practical self-help uses. OTHER MEDICINAL PLANTS
450 other herbs from different herbal traditions with descriptions  
of their therapeutic properties and past and present uses. HERBAL REMEDIES FOR HOME USE
Growing Medicinal Plants
Harvesting & Processing
Making Herbal Remedies
Using Herbal Remedies Safely
Remedies for Common Ailments
Consulting an Herbal Practitioner
Glossary 
Bibliography 
General Index
Index of Herbs by Ailment
Useful Addresses & Acknowledgments6
8
10
14
17
18
28
32
32 
36 
40 
44 
46 
48 
52 
54
156
284
286
288
290
298
299
320
321 
322 
323 
332 
336 
US_004-005_Imprint_Contents. indd   5 26/02/16   4:42 pm
6Introduction
In the twenty years since the first edition of this encyclopedia in 1996, herbal medicine  
has gone through unprecedented change. Herbs, which have always been the principal form 
of medicine in developing countries, have again become popular in the developed world,  as people strive to stay healthy in the face of chronic stress and pollution, and to treat illness with medicines that work in concert with the body’s defenses. A quiet revolution has been taking place. Tens of millions of people now take herbs such as ginkgo (Ginkgo biloba, p. 100)  
to help maintain mental and physical health, and increasingly people consult trained herbal professionals and naturopaths for chronic or routine health problems. Increasingly too, scientific evidence is accumulating to show that herbal medicines can provide treatment that  is as effective as conventional medicines but with few side effects. Sales of herbal medicines continue to grow year after year—by over 50 percent in the U. S. since 2000—and several mainstream pharmaceutical companies now manufacture and market herbal medicines. Plant Medicines
The variety and sheer number of plants with therapeutic properties are quite astonishing. Some 50,000 to 70,000 plant species, from lichens to towering trees, have been used at  
one time or another for medicinal purposes. Today, Western herbal medicine still makes use  
of hundreds of native European plants, as well as many hundreds of species from other continents. In Ayurveda (traditional Indian medicine) about 2,000 plant species are considered to have medicinal value, while the Chinese Pharmacopoeia lists over 5,700 traditional medicines, mostly of plant origin. About 500 herbs are still employed within conventional medicine, although whole plants are 
rarely used. In general, the herbs provide the starting material for the isolation or synthesis  
of conventional drugs. Digoxin, for example, which is used for heart failure, was isolated from common foxglove (Digitalis purpurea, p. 202), and the contraceptive pill was synthesized from constituents found in wild yam ( Dioscorea villosa, p. 91). Ecological Factors
The increased use of medicinal herbs has important environmental implications. Growing 
herbs as an organic crop offers new opportunities for farmers, and sometimes, especially  
in developing countries, opportunities for whole communities. In northeastern Brazil,  for example, community-run herb gardens grow medicinal herbs that are sold to local hospitals. Doctors at the hospital then prescribe these medicines for their patients. The rise in popularity of herbal medicines, however, also directly threatens the survival  of some wild species. Demand for goldenseal (Hydrastis canadensis, p. 105) has become so  great that it now fetches around $140 a pound (£170 a kilo). It was a common plant in the woodlands of northern America two centuries ago, but is now an endangered species, with its survival in the wild threatened by overcollection. This example is by no means unique, and, sadly, many species are similarly threatened across the planet. The extinction of plant species as a result of over-intensive collecting is nothing new. The herb silphion, a member  of the carrot family, was used extensively as a contraceptive by the women of ancient Rome. US_006-007_Introduction. indd   6 26/02/16   4:42 pm7Silphion proved difficult to cultivate and was gathered from the wild in such large quantities 
that it became extinct during the 3rd century ce. Today, if herbal medicine continues to grow at its present rate, it is imperative that 
manufacturers, suppliers, practitioners, and the public use only produce that has been 
cultivated or wildcrafted in an ecologically sensitive manner. About This Book
In the past, books on herbal medicine have tended to focus either on the traditional and 
folkloric use of plants or on their active constituents and pharmacology. The Encyclopedia  
of Herbal Medicine, which features over 550 plants, aims to cover both aspects. It discusses 
each plant’s history, traditions, and folklore, and explains in simple terms what is known from 
scientific research about its active constituents, actions, and potential new uses. It is easy when concentrating on the scientific aspect of herbal medicine to forget that 
much, in some cases all, that we currently know about a particular plant results from its 
traditional use. Moreover, even when a plant has been well researched, herbal medicines are 
so complex and variable that what is currently known is rarely definitive, but rather a sound 
pointer as to how it works. Sometimes the traditional use, insofar as it is based on the 
experience of practitioners, provides an insight into how best to use an herb that is missing 
from scientific knowledge alone. Herbal medicine is, after all, both a science and an art. In choosing the plants profiled in the Encyclopedia, the aim has been to select herbs that are 
commonly used in different parts of the world and are considered to have particular health 
benefits. The index of key medicinal plants (pp. 54–155) contains many herbs that are 
readily available in health stores and pharmacies, for example St. John’s wort ( Hypericum 
perforatum, p. 106). It also includes herbs that are more commonly known as foods, such as 
lemon ( Citrus limon, p. 82), but which, nonetheless, are valuable medicines. The index of other 
medicinal plants (pp. 156–283) contains some less commonly known but important medicinal 
herbs, such as andrographis ( Andrographis paniculata, p. 167), a traditional Indian medicinal 
plant that stimulates recovery from infection and supports normal liver function. A global overview of the history of herbal medicine puts the development of different 
herbal traditions from earliest origins to the present day into perspective. This is complemented 
with features on herbal medicine in Europe, India, China, Africa, Australia, and the Americas, 
providing a rounded picture of herbal medicine worldwide. Herbal medicine is nothing if not practical in its approach, and the Encyclopedia  has a 
detailed self-help section with advice on preparing and using herbal medicines to treat  
a range of common health problems. If more people come to appreciate the immense richness of the world of herbal  
medicine and are able to benefit from the curative properties of medicinal herbs, this  
book will have achieved its aim.
The book aims to provide a comprehensive guide to the medicinal uses of over 550 plants, including their habitats, constituents, actions, and current uses, as well as their historical and traditional uses.
What is the purpose of the book "Encyclopedia of Herbal Medicine"?
The 20th century saw a significant increase in the use of herbal medicine, with many people seeking alternative treatments due to the side effects of conventional medicines.
What is the significance of the 20th century in the development of herbal medicine?
The text does not explicitly state these points, but it does mention the importance of quality control, stating that herbal products should not be stored in clear glass jars or direct sunlight, and that they should be examined before purchase.
What are some of the key points to consider when buying herbal products?
The author acknowledges the importance of traditional knowledge and experience in herbal medicine, stating that "sometimes the traditional use, insofar as it is based on the experience of practitioners, provides an insight into how an herb should be used that is missing from scientific knowledge alone."
What is the author's perspective on the importance of traditional knowledge in herbal medicine?
The text does not mention the 1st century ce specifically, but it does discuss the development of herbal medicine in ancient civilizations, including the Ebers papyrus and the Charaka Samhita.
What is the significance of the 1st century ce in the history of herbal medicine?