Buckthorn is the name of about 150 species of shrubs and small trees native to the Northern Hemisphere. Most buckthorns grow in mild regions.
The common buckthorn is a spiny shrub often grown as a hedge plant. First grown in Europe, this plant was imported to the United States as an ornamental shrub. But in many areas, it has become a troublesome weed that crowds out other plants. It may reach 12 feet (3.7 meters) in height, though it is ordinarily smaller. The leaves are oval and rounded at the base. The flowers, which bloom in May, are small and green and grow in clusters. The fruits are about 1/4 inch (6 millimeters) across. There are four seeds in each fruit. The stems are often thorny. The bark yields a yellow dye and is also used as a laxative.
See also Cascara sagrada.
