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.