Skimmia is the genus of four species of forest trees and shrubs that belong to the Rutaceae, or Rue, family. Depending on the species, the plant's natural habitats range from the region of Afghanistan to the eastern Asian countries, including Taiwan, Japan, and the island of Luzon. The four species vary in height from the shortest cultivar of S. japonica subspecies reevesiana, at almost 2 feet (about 0.5 m), to the S. arborescens, at nearly 49 feet (about 7 m). Japanese skimmia, or S. japonica, is the most cultivated of the four species and often is a popular garden or container plant in many countries. Most skimmia have dark green, oblong-shaped leaves; white flowers; and red, white, or black berries, depending on the species and cultivar.
The skimmia's foliage, which gives off an aroma when something bruises or crushes it, usually is leathery and dark green, although some cultivars have variegated leaves. The elliptical, or oblong, leaves cluster at the end of the branches and remain on the plant throughout the year. Both the male and female flowers stand in upright, closely packed groups with the flower at the end of a reddish-purple stem. The buds are usually red and stay on the plant throughout the winter and open up to reveal white flowers in the spring. The plant bears a drupe type of fruit, meaning that it has a thin outer skin, a soft pulpy middle, and a hard stone or pit that encloses the seed.
Japanese skimmia is the most common species that gardeners use. Generally, growers plant one of the numerous dwarf cultivars because these varieties often are easy to grow and can be planted in containers within regions where it is not hardy. Some of the cultivated plants are small enough to be bonsai plants, approximately 2 feet (about 0.5 m) in height. Most skimmias are dioecious, meaning that a male and a female plant are necessary to produce seed, but some S. japonica ssp. reevesiana are self-pollinating. Many gardeners often find that planting one male specimen with up to six female specimens gives optimum pollination.
In its natural habitat in the Asian forests, the plant is an epiphyte, usually growing on old Japanese cedar trees. An epiphyte is a plant that grows on top of another plant, but does not depend on it for nutrition like a parasite does. Generally, an example of this is moss living on a fallen log.
Skimmia berries are not edible, and usually ingesting even small quantities of berries will give a person an upset stomach. The plant may cause a cardiac arrest if eaten in larger quantities. People who are sensitive to the plant may contract phytophotodermatitis, also called photocontact dermatitis, by getting the sap on their bare skin and exposing it to the sun.