Barberry

Barberries are about 600 species of plants in the genus Berberis, family Berberidaceae, occurring throughout the Northern Hemisphere and South America. Most species of barberry are shrubs or small trees, and many of these have persistent, evergreen leaves. The flowers are small, arranged in clusters, and insect pollinated. The fruits of barberries are multiple-seeded berries.

Barberry hybrids are often cultivated as attractive, ornamental shrubs. Some of these commonly cultivated species include the Japanese barberry (Berberis thunbergii), common barberry (B. vulgaris), Oregon grape (Mahonia aquifolium), and heavenly bamboo (Nandina domestica).

The common barberry is a native of Europe, with attractive foliage and bright-red berries. The common barberry has been widely planted in North America as a garden shrub, and it has escaped to natural habitats, where it can maintain viable populations.

The presence of wild populations of common barberry is considered a significant agricultural problem, because this species is an alternate host in the life cycle of the wheat rust (Puccinia graminis). This fungus is a pathogen of wheat (Triticum aestivum), one of the most important food-producing plants in North America, and the world. The control of populations of common barberry is critical to control of the wheat rust.

The inner bark and roots of the common barberry are bright yellow, and were once used to make a natural dye. Practitioners of folk medicine thought that this yellow color indicated that common barberry could be useful in the treatment of jaundice. However, this barberry has not proven to be useful for this purpose.

There are also native species of barberry in North America, for example, the American barberry (Berberis canadensis) of the eastern United States. Other native species in the barberry family include various shrubs known as Oregon grapes (for example, Mahonia repens). Several species of spring-flowering, herbaceous perennials occur in the understory of hardwood forests in eastern North America, including blue cohosh (Caulophyllum thalictroides), mayapple (Podophyllum peltatum), and twin-leaf (Jeffersonia diphylla). All of these genera of herbaceous plants of eastern North America have counterparts in the same genus is eastern Asia, but not in western North America. This represents a biogeographically interesting, disjunct pattern of distribution.