Appearance

Berberis vulgaris is a deciduous shrub that can reach 13 ft. (4 m) in height. Arching branches which come into contact with the soil can produce new plants.

Foliage

The leaves are oval, 0.75-2 in. (2-5 cm) long, 0.25-0.75 in. (1-2 cm) wide, serrate and occur in clusters of 2-5. Each cluster of leaves is subtended by a short, three-branched spine.

Flowers

Flowering occurs in May to June, when small, yellow, less than 0.25 in. (6 mm) wide flowers develop in dangling racemes. The flowers have an unpleasant odor.

Fruit

Berries are red ellipsoids which are less than 0.3 in. (10 mm) in length and contain 1-3 small black seeds. The fruit is dispersed by birds and other wildlife.

Ecological Threat

Berberis vulgaris is shade tolerant which allows it to easily invade woodlands. It is also an alternate host for wheat rust (Puccinia graminis) which makes the control and removal of this invasive shrub of primary importance. It was introduced to America during the 17th century. Fruit of Berberis vulgaris was used to make jam, the flowers for dye and the thorny shrub provided effective livestock fencing. It is native to central and southern Europe.

Resources

• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alberta Weed Control Act
• City of Ann Arbor Michigan Parks and Recreation
• Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, 1994.
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
• Indiana Invasive Species Council - Invasive Plant List
• Invasive Plant Species of West Virginia
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Maine Invasive Plants
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• Minnesota Noxious Weeds
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture,  Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
• New Hampshire Prohibited Invasive Species
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
• Rhode Island Natural History Survey
• Vermont Noxious Weeds
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References