Gardenias are members of the madder, or Rubiaceae, family. Though not native to either North or South America, they were named for an eighteenth-century American physician and naturalist, Alexander Garden. Gardenias were originally found only in China and Japan, but today there are over 200 different species of gardenia, mostly hybrid, in existence throughout the world. Gardenias are most prevalent in China, Japan, tropical regions of Southeast Asia and the Pacific islands, and South Africa. With proper conditions, gardenias grow into shrub-like bushes or small trees that can reach 5 ft (1.5 m) in height.
Most species of gardenia, however, are very tender plants that require an average temperature of at least 60°F (28.9°C), sunlight with some protection, and just the right amount of humidity. They often survive far better in greenhouses than outside. Gardenias are often rambling plants that form mounds of glossy dark green foliage. The leaves are oval in shape and very shiny. The flowers vary in color from pale yellow with purple markings to creamy white, and they have a classic, heavy, sweet scent reminiscent of green apple. All gardenia blossoms have an almost wax-like appearance and can be either single or double, depending on the species. Most gardenias flower in the winter or early spring, and the blossom is followed by the appearance of a large, yellowish-red, bitter-tasting berry that contains a crystalline compound called acrocetin.
The most commonly listed botanical species of gardenia include:
Gardenias are widely used as exotic ornamental flowers in corsages, as houseplants, and in some regions, as outdoor plants. A yellow silk dye has been made for centuries from the chemical compound acrocetin extracted from the gardenia berry.
Chinese herbal medicine, however, makes the most extensive use of the gardenia. Its Chinese name is zhi zi. The traditional medicinal actions attributed to gardenia
The United States Department of Agriculture Agricultural Research Service phytochemical and ethnobotanical database lists the following species of gardenia as having specific medicinal properties:
The kernel within the gardenia berry is often removed for use in herbal poultices put on sports injuries such as sprains, pulled muscles, or inflammation of nerves. The use of gardenia poultices is particularly common in Chinese medicine. Traditional Chinese practitioners make a paste of the herb with flour and wine. The powdered berry is given in both decoctions and capsules. When gardenia is used to stop bleeding it is usually burned before it is simmered in water.
Chinese herbalists state that gardenia should not be used when there is cold deficiency (watery) diarrhea present.
It is important to remember that Chinese herbal medicine is based upon individual prescriptions developed for each patient and their unique symptoms. Chinese herbs should not be taken, either individually or in formulas, unless a practitioner of Chinese herbal medicine is first consulted.
Gardenia has laxative properties, and can cause loose stools when taken frequently or in large amounts.
Molony, David, and Ming Ming Pan Molony. The American Association of Oriental Medicine's Complete Guide to Chinese Herbal Medicine. New York: Berkley Publishing, 1999.
Phillips, Ellen, and C. Colston Burrell. Rodale's Illustrated Encyclopedia of Perennials. Emmaus, PA: Rodale Press, Inc., 1993.
Reid, Daniel P. Chinese Herbal Medicine. Boston: Shambhala, 1993.
Dr. Duke's Phytochemical and Ethnobotanical Databases. http://www.ars-grm.gov/cgibm/duke/ethnobot.htm
Joan Schonbeck