Chinese Herbs in America
If we look at the origins of plant introductions to American horticulture, we find that a vast number of species have been introduced to American gardens from eastern Asia. These include familiar ornamentals such as forsythia, ginkgo, balloon flower, blackberry lily and many more. These familiar ornamentals also include another common thread they are all used as sources of herbal medicine in Traditional Chinese Medicine (TCM) or Chinese folk medicine traditions. Along with Dr. Shiu Ying Hu at Arnold Arboretum, I have identified nearly 800 species of Chinese medicinal plants in American horticulture.
Starting with the explorations of Marco Polo in the thirteenth century and the travels to China by Portuguese sea traders in the sixteenth century, there has been a steady flow of plant introductions from east to west. When Linnaeuss famous Species Plantarum was published in 1753, 100 species of Chinese plants were described in the seminal botany text. The Royal Botanical Gardens of Kew were actively introducing Chinese plants, and by the time the first volume of William Aitons Hortus Kewensis, or catalog of plants cultivated in the Royal Gardens, Kew, was published in 1789, Chinese plants in English gardens included the Hollyhock (Althaea rosea), Camellia (Camellia japonica), Golden Rain Tree, (Koelreutaria paniculata), Tree of Heaven (Ailanthus altissima), Crape Myrtle (Lagerstroemia indica), Matrimony Vine (Lycium chinense), and Gardenia (Gardenia jasminoides) to name a few. Other introductions such as Japanese Honeysuckle (Lonicera japonica), Tree of Heaven (Ailanthus altissima) and Kudzu (Pueraria lobata) have also become serious invasive alien weeds in the United States.
China, with the richest flora of any part of the temperate world, has for centuries been the logical choice for the selection and introduction of new plants to Europe and North America. Ernest "Chinese" Wilson called one of his many books, China - The Mother of Gardens (The Stratford Co., 1929). Indeed, with a flora of about 30,000 species of vascular plants, China has nearly 50 percent as many plant species as North America. The Chinese use some 5000 plant species as medicine. By comparison about 3,000 species in the North American flora have been used as medicinal plants by native groups in North America (Foster 1998, Foster and Yue 1992).
Baikal skullcap occurs along roadsides, in fields, and high, dry, sandy mountain soils in northeast China and mountains of southwest China, north of the Yangtze river, as well as in eastern Russia. Baikal scullcap grows in full sun, is drought tolerant, and is very hardy. Good soil drainage is essential. Propagate by seeds. The seeds can be planted directly in rows in spring. Emergence takes place in 15 to 20 days. Space individual plants at nine inches.
The first mention is in Shen Nong Ben Cao Jing in the middle class of drugs. The original plant mentioned in the ben cao (Chinese herbals) is the same plant that is used today. Huang-qin is used in prescriptions for all types of fevers, colds, high blood pressure, hypertension, insomnia, headaches, hepatitis, and many other conditions. Chinese and Japanese scientists have confirmed the root has antibacterial, antiviral, diuretic, fever-reducing, liver-protectant, and blood pressure-lowering effects. The root extract has been shown to increase bile production. Clinical studies have indicated utility in chronic hepatitis, with over a 70 percent effective rate. Numerous flavonoids including baicalein and baicalin may be responsible for primary biological activities. An ancient Chinese medicinal herb, Baikal skullcap remains on one of the most widely used plant medicine in Traditional Chinese Medicine (Foster and Yue 1992).
Though the plant had been observed by Westerners in East Asia as early as 1696, the first knowledge English botanists had of it was dried specimens collected by the Rev. G. H. Vatchell near Macao in December 1829. In 1844 Robert Fortune (18121880), a Scottish botanist, sent roots of the plant to the Horticultural Society at Chiswick, introducing the first live balloon flower plants to England. In an 1853 publication the eminent English botanist John Lindley (17991865) called balloon flower the finest herbaceous specimen sent by Fortune from China. The plant is a popular ornamental perennial in American gardens.
In the wild, balloon flower occurs on grassy slopes on hills and mountains, ditches and fields in much of Japan, Korea, north and northeast China, and adjacent Russia. It is easy to grow, adaptable to various growing conditions, and hardy. Numerous cultivars are available in American horticulture. The plant likes cool, moist soils. A sandy, well-drained deep, loam, high in organic matter is suitable. Propagate by seeds sown directly in late April (or after the last frost), or propagated by crown cuttings. The plant was well-known in Chinese and Japanese gardens long before Europeans arrived on their shores, and double-flowered and white forms had already been selected for cultivation.
It is an ancient drug plant, listed in the third class of Shen Nong Ben Cao Jing. Balloon flower root is traditionally used in prescriptions for lung afflictions including cough, excessive phlegm, sore throat, hoarseness, and lung abscesses, among other uses. Recent pharmacological studies confirm expectorant, antitussive, and antibacterial effects. Studies show jie-geng inhibits gastric secretions. Additional studies have shown that the crude root has mild tranquilizing, analgesic, antipyretic, antiinflammatory, vasodilating, hypotensive, and hypoglycemic effects (Foster and Yue 1992).
The plant occurs in most of China, Japan, Indonesia, northern India, eastern Russian in the Ussuri region, and other parts of East Asia. It is thought to be native to north China, but is now widely naturalized throughout the country. Blackberry lily is very easy to grow, preferring a relatively poor dry soil, though will become most luxuriant in a well-drained soil with a fair content of organic matter. Propagation is achieved by dividing the rhizome in March or April and it is easy to grow from seed.
She-gan is listed in the third class of drugs in the ancient Shen Nong Ben Cao Jing. Shen Nong mentions she-gan in the treatment of laryngeal tumors. Modern use in TCM is in prescriptions for the treatment of swelling and pain in the throat, cough with asthma, wheezing, chronic bronchitis, mumps, cough with excessive phlegm, and other conditions. Externally, a wash made from the root has traditionally been used for dermatitis resulting from overwork in rice fields. Recent pharmacological studies have shown that ethanol extracts lower blood pressure, and have experimental antifungal, antibacterial, and antiviral effects. Members of the iris family, including Belamcanda, are considered potentially poisonous (Foster and Yue 1992).
Seeds of eleuthero are available from some seed houses in the United States. It occurs in mountain thickets, sometimes forming impenetrable thickets in Heilongjiang, Jilin, Liaoning, Hebei, and Shanxi Provinces in China, adjacent eastern Russia, the Korean peninsula and the northern island of Hokkaido in Japan. Eleuthero can grow in full sun or partial shade, is hardy, and prefers a cool climate. It prefers a moderately rich, and well-drained soil. Propagation is by seeds (very difficult) cuttings, or division of clumps.
Ci-wu-jia was mentioned in the first class of herbs in Shen Nong Ben Cao Jing. Some scholars question whether the plant described by Shen Nong was indeed Eleutherococcus senticosus. Traditionally, considered good for vital energy (qi/chi), it is used for sleeplessness with many dreams, lower back or kidney pain, deficiency of yang in the kidney and spleen, lack of appetite, and to enhance overall resistance to disease. It was catapulted into world prominence as an adaptogen by Soviet research conducted in the 1950s through the 1970s. Soviet researchers called it an adaptogen, a term coined in 1947 by N.V. Lazarev, to describe the action of a substance that helps to increase "non-specific resistance of an organism to adverse influence." The late I.I. Brekhman, a leading researcher on eleuthero, defines an adaptogen as a substance that is 1). innocuous (safe), causing no or minimal side effects; 2). a substance that must have a nonspecific action, increasing resistance to a wide range of environmental or other physical factors; 3). a substance that must have a normalizing action in the body, irrespective of a diseased state. Under the names of "eleuthero" and "Siberian ginseng," a wide array of products derived from the plant are available in health and natural food markets in the United States (Foster and Yue 1992; Farnsworth et al. 1985, Foster 1996a).
Forsythia is widely planted and naturalized in Japan, Europe, and the United States. In China, it grows in low mountain thickets throughout much of the country. Most Forsythia grown in American horticulture is a hybrid, F. x intermedia, a cross between F. suspensa and F. viridissima. Forsythia likes full sun or dappled shade, a warm, relatively moist situation, and is hardy throughout the United States. Numerous cultivars are available. Depending upon whether it is a hybrid or species, it can be propagated from seeds, divisions, cuttings, or layering. In short, if you cant grow Forsythia, you cant grow anything.
The use of the seed capsules is first mentioned in the third class of herbs in Shen Nong Ben Cao Jing. Today the seed capsules are used for fevers, swelling, swollen lymph nodes, urinary tract infections, and inflammatory conditions. Experimentally, lian-qiao is a broad spectrum antibiotic against numerous gram-positive and gram-negative bacteria. Forsythiaside is considered the strongest bacteriostatic compound. The fruits have also been shown to have antifungal, antiinflammatory, antipyretic, antinauseant, and diuretic action. It is virtually unknown as a medicinal herb in the United States (Foster and Yue 1996, Leung and Foster 1996).
It is first mentioned in the superior class of drugs in Shen Nong Ben Cao Jing (Hu 1976, 1977). The first Western description of the plant was that of Père Jartoux, whose 1709 observations were first published in 1711. While seed of Panax ginseng is offered by a few seed sources in the United States, it is unclear whether or not the plant has been authenticated in American horticulture.
Asian ginseng is perceived as a tonic and adaptogen to replenish vital energy (qi/chi), increase strength, increase blood volume, promote appetite, quiet the spirit and give wisdom. Like eleuthero it is considered an adaptogen. Over the past 50 years there have been nearly 3000 scientific studies published on all aspects of ginseng. The vast majority have focused on Asian ginseng, rather than American ginseng. Studies have also looked at the adaptogenic and performance-enhancing effects of ginseng, including adaptation to dark, high and low temperatures, work efficiency, and athletic performance. In Germany, it is approved as a tonic for invigoration to treat fatigue, reduced work capacity and lack of concentration, and as a tonic during convalescence (Foster and Yue 1992; Foster 1996b, 1996d).
Ginkgo is a deciduous tree growing to 130 feet in height. Numerous cultivars are available in American horticulture. Ginkgo is generally believed to be found only in cultivation. H.L. Li (1956) provided a convincing argument for its natural occurrence in the mountains of the southern border area of Anhui, Jiangsu, and northern Zhejiang. While not definitively confirmed from the wild in China, it has been found growing in remote forests in Zhejiang province over a ten square mile area. The occurrence of ginkgo as a wild as opposed to cultivated tree or escape has been much disputed over the past few centuries (Del Tredici 1991).
Ginkgo leaf extracts are among the better-selling herbal medicine in Europe. Most research has focused on the use of the complex extracts to increase circulation to the extremities as well as the brain. Clinical use is backed by more than 400 scientific studies, conducted since the late 1950s. The extract is used for circulatory conditions often associated with elderly populations, such as poor circulation to the brain and lower legs. It has also been researched for the treatment of ringing in the ears (tinnitus), male impotence, degenerative nerve conditions such as multiple sclerosis, and other disease problems. In China, the potentially toxic seeds are used in prescriptions for asthma, coughs with phlegm, enuresis, bronchitis with asthma, chronic bronchitis, and urinary problems (Foster and Yue 1992, Leung and Foster 1996, Foster 1996c).
Houttuynia occurs in moist, shaded lowlands from India, to China, plus Japan, Taiwan, and other Pacific islands. It is a low-growing, creeping perennial herb, easily propagated by dividing the clumps. Houttuynia likes a cool, moist, rich, shaded situation. A number of cultivars are available including Chameleon, (also called Variegata) with green, cream and pink-red splotches, and Flore Pleno, sporting enlarged double white bracts beneath the flower head, with purple-tinged leaves.
Yu-xing-cao is used in prescriptions for vomiting of blood with pus due to lung abscesses, edema, urinary infections, chronic bronchitis, hemorrhoids, rheumatism, topical infections and many other conditions. Experimentally, the herb has a diuretic action, strengthens capillary walls, is antifungal, antibacterial, and antiviral, plus lowers blood pressure. The herb may have some immune system stimulating activity. One study showed that a decoction of the herb significantly enhanced the phagocytic activity of human peripheral leukocytes against Staphylococcus aureus. Recent pharmacological and chemical research on the herb has been conducted in Germany (Foster and Yue 1992).
The medicinal use of the flowers is mentioned in early Chinese herbals including Ming Yi Bie Lu, attributed to Tao Hong-jing (about 400 A.D.) and Lu Chan Yan Ben Cao ("Materia Medica from Steep Mountainsides") attributed to Wang-jie, and dated about 11631224 A.D. from the Nan-Song dynasty. The use of the stems is first mentioned in Ben Cao Jing Ji Zhu, attributed to Tao Hong-jing, published around the year 500 A.D. The flower preparations are used in prescriptions to treat infections of the upper respiratory tract, fever, colds, flu, and other conditions. The stem and branches are used similarly and also valued as an antiinflammatory. Experimentally flower extracts have shown strong antibacterial and antiviral activity, a serum cholesterol lowering effect, antispasmodic, diuretic, and stomachic effects, as well as immunostimulatory activity (Foster and Yue 1992, Leung and Foster 1996).
The plant promised to be a food, fodder, fiber, shade-producing economic bonanza. From 19101953, realizing its potential as a hay and fodder crop, USDA researchers pushed its development as a new crop. The Soil Erosion Service, started in 1933 during Franklin Roosevelts New Deal, saw the potential of the plant for control of soil erosion. That agency, which changed its name to the Soil Conservation Service two years later, extensively planted kudzu for erosion control. By 1945, an estimated 500,000 acres of the Southeast United States were covered in kudzu. Today, the plant is the vegetative plague of Southern fields and forests. Like Japanese Honeysuckle, perhaps the best way to control kudzu is to find a way to utilize it. Wild kudzu grows in moist shaded areas throughout most of China. Its first mention comes in the ancient herbal of Shen-nong Ben Cao Jing (2000 BC).
Official in the 1985 Chinese Pharmacopoeia, kudzu root or ge-gen is traditionally used as a diaphoretic for fevers accompanied by discomfort or pain in the neck and back. It is also used to relieve thirst caused by fevers, and for hypertensive headaches, and coronary heart disease. Experimentally intravenous injections of the active component of the root (flavonoids, including daidzin, daidzein, and puerarin) reduces blood pressure and venous obstruction. Oral administration of the crude root slightly reduces blood pressure. It is used as a folk remedy to sober-up an unconscious drunk. For this purpose the root is pulverized to obtain the fresh juice, enough to obtain 12 shot-glassfuls. This treatment is said to help the drunk regain consciousness (Foster and Yue 1992). A widely publicized 1993 study by W. M. Keung and B. L. Vallee stimulated present interest in Kudzu. In this study both daidzin and daidzein in doses of 150/mg/kg/day were found to suppress the free choice of ethanol in Syrian Golden hamsters. The authors concluded that kudzu root extracts, as well as daidzin and daidzein (an aglycone of daidzin), may offer therapeutic choices in the treatment of alcohol abuse. This study confirmed traditional use of the use of the root (as well as the flowers) for the treatment of patients under the influence of alcohol.
These few examples show us that appreciation for plants is more than meets the eye. While we move forward into the future of modern medicine, traditional folk wisdom may be instrumental in providing the research leads necessary for finding treatments for cancer, heart disease, and other human maladies. The plants providing those leads may be no further away than the backyards of the researchers who study them.
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