A contribution to our knowledge of ginseng.

The Chinese people discovered ginseng and used it as a revitalizing agent since time immemorial. They are still the world's major consumers of this plant drug. The commercial product of ginseng comes from two species of the genus Panax in the family Araliaceae. These species are P. ginseng C. A. Meyer which is the source plant of the Chinese, Korean and Japanese brands of ginseng, and P. quinquefolius L., which is the source of American ginseng. Phytogeographically, ginseng demonstrates the classical bicentric pattern of plant distribution, with closely related species in eastern Asia and in eastern North America. Ecologically, ginseng is an undergrowth of hardwood mixed deciduous forest. It prefers the northern or the northeastern slope of a hill. Species of the genus Tilia are good indicators of the proper environmental condition for the growth of ginseng. Morphologically, ginseng is a perennial herb with fleshy root, a single annual stem bearing a whorl of palmately compound leaves, and a terminal simple umbel of small 5-merous flowers. The flowers are soon followed by pea-sized fruits developed from inferior ovaries. The fruits are red when ripe. Ginseng is propagated by seed. The commercial products of ginseng consist primarily of roots 2-20 years old. Within this age range, the older the root the higher the market value, provided they are grown in proper conditions. The methods of curing the roots change the color and shape of the products. Chinese ginseng is prepared from roots bleached, boiled, steamed, or sugared in curing. The cultural background for the uses of ginseng by the Chinese people is explained. Ginseng may be used alone in the form of tea, powder, or as a masticatory. It is also used in combination with other drugs of animal, mineral, or plant origin. Forty-two recipes are selected from Pen-ts'oa kang-mu and translated into English for the first time to show the various ways by which ginseng is used in traditional Chinese medicine. A systematic summary of the companion plant drugs of ginseng is presented in the form of a table, showing the distribution of the species in the plant kingdom. The scientific names of the species are given in full.