Common name: Common barberry or European barberry
Scientific name: Berberis vulgaris L.
Europe (Gleason and Cronquist 1991)
Common barberry is a perennial shrub that can reach up to 3 m (10 ft) in height. It has small, dull green, alternate leaves that are oval, with serrated or jagged margins that are 2-5 cm (0.75-2 in.) in length (see Figure 1) (IPANE 2007). The branches are dull gray or yellowish-gray and contain spines that are usually in groups of 3 (see Figure 2). In spring, it has yellow flowers (4-6 mm across) that are arranged in racemes 3-6 cm (1-2 in.) in length, with 10 to 20 flowers on each raceme (see Figure 3). In late summer or autumn, it has small oblong red berries about 1 cm (0.4 in.) long with 1 to 3 small, black seeds (IPANE 2007).
- ECOLOGICAL THREAT:
As a host plant for Puccinia graminis or stem rust, common barberry can be a huge threat to neighboring plants, especially wheat. Stem rust usually infects the leaves of the common barberry (see Figure 4) (Leonard 2001) and can then spread in two different ways. First, by providing a greater number of sites of sexual reproduction for the fungus than previously available, the rust can spread more rapidly and harm neighboring plants (Roelfs 1982; Peterson et al 2005). In addition, dormant teliospores of the fungus can also survive on common barberry; without common barberry, the teliospores would have been a dead end in the life cycle of the fungus (Leonard 2001). Although there is direct evidence that common barberry can be a harmful agricultural pest, evidence of its invasiveness is mostly anecdotal such as Cronon’s (1983) descriptions of it as a noxious weed and historical sources that have noted its high rate of spread (Peterson 2003).
Today, common barberry is found sporadically in small, isolated populations in some regions and in larger populations along the coast of New England (IPANE 2007). For the most part, it no longer has attributes of an aggressive invader, and its populations do not appear to be expanding (Silander and Klepsis 1999). There is still the risk that it could re-emerge as an invader, since the fruits may be dispersed long distances by birds that feed on them, and the seeds can remain viable even after they have passed through the birds’ digestive tracts (Peterson et al 2005). Continued long-distance dispersal of common barberry seeds could potentially connect smaller populations to form larger ones. Because of this, a Minnesota study of sites where common barberry had once been identified and removed concluded that regular surveys of formerly invaded sites as well as neighboring sites were necessary, especially for sites adjacent to wheat fields (Peterson et al 2005). This would ensure that populations of common barberry remain small and far away from where they can spread stem rust and harm wheat crops.
- DISTRIBUTION IN THE USA:
- HABITAT IN THE USA:
Common barberry can be found in a variety of habitats including abandoned fields, coastal grasslands, edges, floodplain forests, forest wetlands, disturbed areas such as roadsides, habitat edges, pastures, and yards or gardens. It is most often found in open-canopied forests and occasionally along roads. It is also capable of growing in calcareous soils (IPANE 2007).
Observations of common barberry in the United States date back to the 17th century (IPANE 2007). It was originally introduced in multiple locations for ornamental, food, and medicinal purposes (Peterson 2003). The fruits of the berries can be made into jam, the flowers into yellow dye, and the shrubs are sometimes used as thorn hedges (IPANE 2007). Common barberry was also reported to have medicinal properties including as a treatment against scurvy, bladder trouble, jaundice, constipation, appetite loss, and fever (Peterson 2003).
In the early 1900s, stem rust epidemics started wiping out agricultural fields, particularly wheat fields (Peterson et al 2005). When it was discovered that common barberry was an alternative host of the stem rust fungus, Puccinia graminis, a federal Barberry Eradication Program was implemented from 1918 through the 1980s (Peterson et al 2005), and common barberry was cleared from a large part of its range in the United States by the early twentieth century (Silander and Klepeis 1999).
- BIOLOGY & SPREAD:
Historically, the main vector of the introduction and spread of common barberry was humans. The many uses and hardiness of common barberry made it an ideal plant for colonists to have around, and it was often introduced into human-settled landscapes such as lawns, gardens and farms, later spreading into other habitats (Peterson 2003). Common barberry can be propagated by seeds or cuttings (Peterson 2003), making it easy to transport. Today, humans are no longer the main vector of spread: birds, small mammals and even cattle have been observed to be dispersers of the fruit of common barberry (Kern 1921; IPANE 2007).
- MANAGEMENT OPTIONS:
Due its ability to spread stem rust, many regulations are currently in place to prevent further introductions of this species. Its sale is currently prohibited in states including New Hampshire, Connecticut, and Massachusetts (IPANE 2007; NRCS 2007). In order to manage populations that have already been established, the IPANE website (2007) suggests that control methods for Japanese barberry (Berberis thunbergii) can be applied to common barberry. These methods include pulling by hand or weed wrench, mowing or cutting, and herbicides such as triclopyr can be applied to leaves or cut stumps (CIPWG 2007).
In the past, manual and chemical control methods were also used, including pulling, cutting, and applications of salt, kerosene, crushed rock salt, and ammonium sulfamate (Foster et al 2003; Peterson 2003). Sodium arsenite was also used at some point but was discontinued after it was discovered that the chemical was killing off livestock and other animals (Peterson 2003). Past methods of control also involved large-scale volunteer recruitment and outreach campaigns to educate the public about the harmfulness of common barberry, particularly its threat to food security (Peterson 2003).
- GENETIC STUDIES:
Common barberry has been known to hybridize with a closely related species, Japanese barberry (Berberis thunbergii DC), and produce viable offspring, Berberis x ottawensis Schneid (IPANE 2007). Thus far, there has been little evidence of the hybrid’s invasiveness, and it is mainly used as an ornamental (Silander and Klepeis 1999). According to IPANE (2007), the morphology of B. x ottawensis is a blend of that of B. vulgaris and B. thunbergii and the characteristics are summarized in the following table adapted from the IPANE website (see Table 1).
In a phylogenetic study of the Berberis genus, the internal transcribed spacer (ITS) region of nuclear ribosomal DNA of B. vulgaris was sequenced along with 78 other taxa within the genus to examine whether certain traits within the genus arose once and spread to other geographic areas or whether they arose independently in different areas (Kim et al 2004). From this data, they found that the appearance of Berberis species with simple leaves (possible ancestors of both B. vulgaris and B. thunbergii) arose independently in Asia and South America and spread to other parts of the world from those two source populations (Kim et al 2004).
- ECONOMIC THREAT:
Stem rust epidemics are capable of wiping out 50 to 70% of crops over large areas and completely destroying individual fields (Peterson 2005), which results in a tremendous economic loss. As a host for Puccinia graminis (Roelfs 1982; Leonard 2001; Peterson et al 2005), it contributed significantly to this monetary loss in the past when common barberry was widely occurring. Currently, common barberry does not pose this threat, but it has the potential to re-emerge as an invader if populations are not kept in check and away from regions where wheat is grown (Peterson et al 2005).
- LOCAL (MASSACHUSETTS) IMPACTS:
Because common barberry is not a widely occurring plant in the state (see Figure 5) (IPANE 2007), the impacts of common barberry in Massachusetts are minimal. This species is on the Massachusetts prohibited plant list and has been banned from propagation or importation since January 2006 (MDAR 2006).
Figure 5: Distribution of Common barberry in Massachusetts (by town)
For more information concerning the management of common barberry, please contact:
J. Leonard, Department of Plant Pathology, University of Minnesota-Twin
Malik, Animal and Plant Health Inspection Service (APHIS), USDA
D. Peterson, Department of Entomology, Soils, and Plant Sciences, Clemson
B. Sutton, Department of Plant Pathology, North Carolina State University
- SUGGESTED ALTERNATIVES:
Native alternatives suggested for common barberry are the same as the ones for Japanese barberry. They include beautyberry (Callicarpa americana), mountain mahogany (Cercocarpus spp.), silverberry (Elaeagnus commutatus), sweetspire (Itea virginica), bayberry (Myrica spp.), roseshell azalea (Rhododendron vaseyi), buffaloberry (Shepardia spp.), coralberry (Symphoricarpos orbiculatus), Chenault snowberry (Symphoricarpos x chenaultii), lowbush blueberry (Vaccinium angustifolium), and velvetleaf blueberry (Vaccinium myrtilloides) (Cullina 2003).
- OTHER LINKS:
Invasive Plant Atlas of
New England: http://www.lib.uconn.edu/webapps/ipane/browsing.cfm?descriptionid=41
USDA Plants Database:
Animal and Plant Health Inspection Service:
Dolaporn Novem Auyeung, University of Massachusetts, Boston, MA
Connecticut Invasive Plant Working Group (CIPWG). 2007. “Japanese barberry (Berberis thunbergii).” http://www.hort.uconn.edu/cipwg/art_pubs/GUIDE/x10jbarberry.html
. Wang, New York New EnglandWildflower Society. http://www.newfs.org/conserve/docs/invalt2.pdf New England(IPANE). 2007. http://www.ipane.org http://www.ars.usda.gov/Main/docs.htm?docid=10755&pf=1&cg_id=0 Lexington, KY.