Celastrus is one of the genus groups of plants in the celastraceae, or staff tree, family. It is native to parts of Asia, Australia, and Canada and the US in North America. It is a deciduous shrub and is a climber that, on average, often reaches heights of more than 20 feet (3 m). Generally in America it is best known for its colorful fruit and used as a fall decoration. In other countries, some species of Celastrus have medicinal uses, especially the Asian and Australian species.
People often use the names waxwork or false bittersweet for the Celastrus plants native to America and Canada. True bittersweet is Solanum dulcamara, a member of the poisonous nightshade family. Both of these plants have small, greenish-white flowers that evolve into capsule-like fruit that contain yellow or crimson seeds. These usually remain on the plant all winter, making it a winter garden favorite. Generally, the seeds are bitter and have a very unpleasant odor.
Typically, Celastrus plants are dioecious, meaning that the male and female flowers grow on different plants. Very few species and cultivars have the male and female flowers on the same plant. A gardener who wants the colorful berries each fall should research this further to ensure the plant he or she obtains will pollinate and bear fruit. Growers propagate the plants by sowing seeds, rooting cuttings, and soft or mature stem air rooting.
Several of the species are native to the Orient. One of the Oriental Celastrus plants is the C. articulates from Japan that is a vigorous climber, reaching heights of 40 feet (12 m) or more. The C. angulatus, native to parts of China, usually is not hardy in colder regions. C. hypoleucus, also from parts of China, has large, bluish-colored leaves. The Korean species, A. flagellaris, is different because it has short, hooked spines.
American bittersweet, C. scandens, is native to parts of North America. It typically climbs to heights of 20 feet (6 m) if it has a sturdy host to scale. Often gardeners plant it for its showy orange-yellow fruits. In gardens, growers usually train it to cover a trellis or a wall. In the wild, it generally grows on fence lines, trees, and up rocky slopes.
Some US states have banned the sale of Oriental Celastrus plants because they are an invasive species. A person usually can distinguish between the two by examining the leaves. Generally, the Oriental bittersweet leaves are almost round, and the American bittersweet plant has narrower leaves than its Oriental cousins do.
In Australia, some people grow C. dependus, known as the intellect tree or black oil tree, for its oil. This climbing staff plant with a yellowish, corky bark has unisexual flowers, meaning that it is self-pollinating. The seed pods have one to six seeds that produce a dark brown oil, often called Celastrus oil. Many believe this oil improves memory, facilitates learning, and improves mental well-being.
The C. paniculatus grows in almost all of India, and people use it for medicinal purposes. Like the Australian plant, many believe it helps the mental process. People often use the oil for curing sores, ulcers, and rheumatism.