Shrubs , deciduous, 1-3 m. Stems dimorphic, with elongate primary and short axillary shoots. Bark of 2d-year stems gray, glabrous. Bud scales 2-3 mm, deciduous. Spines present, simple or 3-fid. Leaves simple; petioles 0.2-0.8 cm. Leaf blade obovate to oblanceolate or almost elliptic, 1-veined from base, 2-6(-8) × 0.9-2.8 cm, thin and flexible, base short- to long-attenuate, margins plane, finely serrate, each with (8-)16-30 teeth 0-1 mm high tipped with spines or bristles to 0.6-1.4 × 0.1 mm, apex rounded or obtuse; surfaces abaxially dull, smooth, adaxially dull, ± glaucous. Inflorescences racemose, lax, 10-20-flowered, 2-6 cm; bracteoles membranous, apex acute. Flowers: anther filaments without distal pair of recurved lateral teeth. Berries red or purple, ellipsoid, 10-11 mm, juicy, solid.
During the eighteenth and nineteenth centuries, Berberis vulgaris was very commonly cultivated in North America for thorn hedges and as a source of jam and yellow dye. It frequently escaped from cultivation and became naturalized over a wide area of eastern North America. It is susceptible to infection by Puccinia graminis . As the most important alternate host of this fungus, it has been the subject of vigorous eradication programs, and it is now infrequent or absent in many areas where it was once frequent (A. P. Roelfs 1982).
Shrub 1 - 3 m tall Leaves: alternate, short-stalked, dull green, 2 - 8 cm long, 0.9 - 2.8 cm wide, elliptic to inversely egg-shaped with a rounded to blunt tip and tapered base, with eight to 30 spine-tipped teeth per side, thin and flexible, more or less covered with a whitish waxy coating (glaucous) beneath. Flowers: borne ten to twenty in a loose inflorescence 2 - 6 cm long, subtended by membrane-like bracts with pointed tips. The six yellow petal-like sepals fall soon after flowering, each of the six yellow petals has two basal glands, and each filament lacks a pair of curved lateral teeth. Fruit: a red or purple berry, 8 - 12 mm long, elliptic, juicy. Twigs: yellowish to yellowish red, becoming gray with age, grooved, usually with three-pronged spines. Form: freely branched and arching, with long branches and short lateral branchlets.
Similar species: Berberis aquifolium and Berberis repens both have leathery compound leaves and bluish black berries, and they lack spines and short lateral branchlets. Berberis canadensis is upright and sparingly branched with notched petals, purplish to brown twigs, and leaves with less than twenty teeth. Berberis thunbergii has simple-spined twigs, non-toothed leaves, and solitary or few-flowered clusters of flowers.
Flowering: May to June
Habitat and ecology: Introduced from Europe, this plant escaped from cultivation and became common in woodlands. Eradication programs removed the species from much of the region, but a few populations still exist in Lake County, Illinois near Lake Michigan.
Occurence in the Chicago region: non-native
Notes: Common barberry was widely planted in the 1700s and 1800s as a hedge and was used to make jams and yellow dyes. Unfortunately, it commonly escaped from cultivation in the eastern United States. It is the most important alternate host of Puccinia graminis, the pathogen causing stem rust of cereal crops. Eradication programs have led to the removal of this species from many areas of the country.
Etymology: Berberis is a Latinized form of the Arabian name for barberry. Vulgaris means common.
Freely branched, to 3 m, the twigs gray or yellowish-gray; lvs obovate or obovate-oblong, 2-5 cm, finely spinulose-denticulate, the veinlets prominently reticulate beneath; racemes 3-6 cm, with 10-20 fls on pedicles 5-10 mm; pet entire; fr 1 cm, tart; 2n=28. Native of Europe, formerly much planted and escaped, now largely purposefully exterminated as the alternate host of the common "stem" rust of wheat. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species was formerly much used as an ornamental shrub. When it was learned that it was responsible for the black stem rust on wheat, oats, rye, barley, and about 75 wild and cultivated grasses, which resulted in a loss of approximately fifty million dollars annually, an active campaign was started by the U. S. Department of Agriculture for its extermination in the wheat area of the U. S. See U. S. Dept. Agric. Farmer's Bull. 1544: 1-28. 1927, and Purdue Univ. Agric. Exper. Sta. Bull. 145: 1-12. 1926.
Indiana Coefficient of Conservatism: C = null, non-native