Berberis thunbergii (Japanese barberry)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Hosts/Species Affected
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Soil Tolerances
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Pathway Vectors
- Plant Trade
- Impact Summary
- Environmental Impact
- Impact: Biodiversity
- Social Impact
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Berberis thunbergii DC.
Preferred Common Name
- Japanese barberry
International Common Names
- French: vinettier de thunberg
Local Common Names
- Finland: Japaninhappomarja
- Germany: Japanischer Sauerdorn; Thunbergs Berberitze
- Italy: berberis
- Netherlands: Japanse berberis; zuurbes
- Poland: berberys thungerga
- Sweden: häckberberis; haeckberberis
- BEBTH (Berberis thunbergii)
Summary of InvasivenessTop of page B. thunbergii poses a significant threat to natural areas due to its popularity as a landscape shrub, ability to tolerate full shade, and the dispersal of its prolific seeds by birds (Bargeron et al., 2003). The combination of multiple forms of vegetative and seed-based reproduction with very low rates of plant mortality are reasons for the ability of B. thunbergii to rapidly produce dense, persistent populations (Ehrenfeld, 1999).
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Ranunculales
- Family: Berberidaceae
- Genus: Berberis
- Species: Berberis thunbergii
Notes on Taxonomy and NomenclatureTop of page The genus Berberis is large, containing over 500 species. The name Berberis thunbergii is universally accepted for this shrub. Other names that have been reported as synonyms, including B. sinensis, B. japonica, B. trifoliata, actually represent separate species. Three varieties are recognized by USDA-ARS (2003); var. atropurpurea, var. maximowiczii and var. minor, though these may represent varieties in the introduced range only. Numerous cultivated forms are available for sale as ornamental plants, some of which share these varietal names.
DescriptionTop of page B. thunbergii is a perennial, compact, woody shrub with arching branches, growing 60-190 cm high. It is as wide as tall or wider than tall. The stems have a grey brown, striated, thin bark, and a bright yellow inner bark and wood. Stems are woody, slender and zig-zag in shape with a single, very sharp spine at each node below each rosette of leaves. These spines are metamorphosed leaves of the shoots, bearing fascicles of small leaves in their axes. Roots are yellow inside. The plant has many stemmed, alternate, slightly bluish-green to green to dark reddish purple, wedge-shaped, untoothed leaves, which are obovate to spatulate, usually obtuse, entire, narrowed at base to a short petiole, 13-32 mm long in whorls or clusters. The leaves are glaucescent beneath. The yellow flowers, produced in late April or May, are 6 mm wide, in elongate racemes, growing in contracted umbel-like clusters, or sometimes solitary. The flowers have six petals, which are similar in appearance to the four sepals, but are usually smaller than the sepals and with two glands at the base of each. Flowers are bisexual and grow in drooping clusters along the lower sides of the branches. Fruits are ovoid, dry or slightly juicy but solid berries, scarlet in colour, 8-13 mm long, persisting well into the winter (Rhoads and McKinley Klein 1993; Brunelle and Lapin, 1996; Rhoads and Block, 2000; IPANE, 2001). There are several varieties used for ornamental purposes or as barrier plantings.
Plant TypeTop of page Perennial
DistributionTop of page B. thunbergii is native to Japan. It is widely naturalized throughout North America due to its planting as an ornamental and then escaping from its intended habitat. The plant is also naturalized in Europe, and is continuing to spread in south-western Germany (Böcker and Dirk, 1998), Scandinavia (Hartvig, 2002) and other European countries. It is not known to occur in East Africa (Luke Q, National Museums of Kenya, personal communication, 2004), though is assumed to be present in South Africa, as it proposed as a Category 3 Invader Plant under the Conservation of Agricultural Resources Act (Wildly E, Alien Invader Plants Project, South Africa, personal communication, 2004) though no published record exists.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Planted||Reference||Notes|
|Japan||Present||Native||Not invasive||Natural||USDA-ARS, 2003|
|Canada||Present||Introduced||Invasive||Planted||Royal Botanical Gardens Canada, 2003|
|-Nova Scotia||Present||Introduced||Invasive||Planted||Royal Botanical Gardens Canada, 2003|
|-Ontario||Present||Introduced||Invasive||Planted||Royal Botanical Gardens Canada, 2003|
|-Prince Edward Island||Present||Introduced||Invasive||Planted||Royal Botanical Gardens Canada, 2003|
|-Quebec||Present||Introduced||Invasive||Planted||Royal Botanical Gardens Canada, 2003|
|USA||Present||Present based on regional distribution.|
|-New Hampshire||Present||Introduced||Planted||USDA-NRCS, 2002|
|-New Jersey||Present||Introduced||Planted||USDA-NRCS, 2002|
|-New York||Present||Introduced||Planted||USDA-NRCS, 2002|
|-North Carolina||Present||Introduced||Planted||USDA-NRCS, 2002|
|-North Dakota||Present||Introduced||Planted||USDA-NRCS, 2002|
|-Rhode Island||Present||Introduced||Planted||USDA-NRCS, 2002|
|-South Carolina||Present||Introduced||Planted||USDA-NRCS, 2002|
|-South Dakota||Present||Introduced||Planted||USDA-NRCS, 2002|
|-West Virginia||Present||Introduced||Planted||USDA-NRCS, 2002|
|Austria||Present||Introduced||Planted||Wittman and Pilsl, 1997|
|Belarus||Present||Introduced||Planted||Shapiro et al., 1983|
|Germany||Present||Introduced||Invasive||Planted||Böcker and Dirk, 1998|
|Netherlands||Present||Introduced||Planted||Christenhusz et al., 2001|
|Poland||Present||Introduced||Labanowski, 1990; Soika and labanowski, 1998|
|Russian Federation||Present||Present based on regional distribution.|
|-Northern Russia||Present||Introduced||1864||Planted||Brunelle and Lapin, 1996|
|Australia||Present||Present based on regional distribution.|
|-New South Wales||Present||Introduced||Royal Botanic Gardens Sydney, 2003; Hosking, 2003|
|-Victoria||Present||Introduced||Planted||Royal Botanic Gardens Sydney, 2003|
History of Introduction and SpreadTop of page B. thunbergii was discovered in Japan and sent to the St Petersburg Botanic Garden, Russia, by the Russian botanist Carl Maximowicz in 1864. About 10 years later, seeds from the St Petersburg Botanic Garden were obtained by the Arnold Arboretum in Massachussetts, USA and from there, introduced to elsewhere in North America (Brunelle and Lapin, 1996). The plant is commercially sold as a garden and landscaping plant, and has been repeatedly introduced to many countries. From gardens and parks, it has escaped into unmanaged habitats.
Risk of IntroductionTop of page B. thunbergii is still traded as an ornamental plant. It is sold by nurseries, garden centres and via the internet. In South Africa, B. thunbergii has been proposed as a Category 3 Invader Plant under the Conservation of Agricultural Resources Act, as a species which have amenity value and which may be grown, but not planted, propagated, imported or traded (Henderson, 2001; Wildly E, Alien Invader Plants Project, South Africa, personal communication, 2004). The plant is listed as an invasive weed by the Southeast Exotic Pest Plant Council and the state of Wisconsin, USA (Anon., 1988; USDA-NRCS, 2002.) and it is illegal to sell B. thunbergii plants in Canada (IPANE, 2001).
HabitatTop of page B. thunbergii can be found in a variety of different habitats, forming dense, continuous stands. It is often found in natural woodland, mostly temperate deciduous, but also wetlands in forested areas, and is common in areas prone to browsing by deer. However, it is also known to invade grasslands, both managed and natural, field margins, roadsides and abandoned land.
Habitat ListTop of page
|Terrestrial – Managed||Managed forests, plantations and orchards||Present, no further details||Harmful (pest or invasive)|
|Managed grasslands (grazing systems)||Present, no further details||Harmful (pest or invasive)|
|Disturbed areas||Present, no further details||Harmful (pest or invasive)|
|Rail / roadsides||Present, no further details||Harmful (pest or invasive)|
|Urban / peri-urban areas||Present, no further details||Harmful (pest or invasive)|
|Terrestrial ‑ Natural / Semi-natural||Natural forests||Present, no further details||Harmful (pest or invasive)|
|Natural grasslands||Present, no further details||Harmful (pest or invasive)|
Hosts/Species AffectedTop of page B. thunbergii is not generally a weed of agriculture but is a weed of woodlands. The plant invades abandoned fields and early successional woodlands (Randall and Marinelli, 1996) and is especially invasive in areas prone to browsing by deer (Koh et al., 1996). B. thunbergii can form extensive populations under a closed forest canopy.
Biology and EcologyTop of page Genetics
The barberry genus is generally diploid, with a chromosome number of 2n=28 (Cadic, 1992). There are many interspecific hybrids, such as those between B. thunbergii and B. vulgaris (B. x ottawensis Scheid.), and B. thunbergii and Julian barberry (Rehder, 1940).
Physiology and Phenology
The fruits of B. thunbergii mature from July to October and often persist on the shrub during winter. Seeds require cold stratification for about 90 days (Davis, 1927). Germination is epigeal and seedlings develop rapidly (Terabayashi, 1987).
B. thunbergii reproduces from prolific seeds, rhizomes or layers. Seeds have a germination rate of about 90%. The seed is dispersed by a number of birds including ruffed grouse, bobwhite, pheasant, and wild turkey (Bargeron et al., 2003). Plants growing in dense shade may not flower and fruit as heavily as those in more open sites. B. thunbergii is pollinated by insects.
B. thunbergii can grow in partial or full shade, but can tolerate full sun. Due to the shade tolerance and high germination rate of B. thunbergii, an extensive population can become established in a short time under a closed forest canopy. Severe drought or extreme winters have little effect on overall mortality or seed production (Bargeron et al., 2003). Optimum growth and quality of plants is produced with moderate intensities of light (Knox and Hamilton, 1982), but even at less than 1% full sun, some positive stem growth can occur (Silander and Klepeis, 1999). Soil moisture conditions can be dry to moist, though the plant does not withstand extremely moist conditions. B. thunbergii is moderately drought tolerant but not tolerant to saline soils (Monk and Peterson, 1962).
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Absolute minimum temperature (ºC)||-28||0|
|Mean annual temperature (ºC)||0||0|
|Mean maximum temperature of hottest month (ºC)||0||0|
|Mean minimum temperature of coldest month (ºC)||0||0|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Dry season duration||0||0||number of consecutive months with <40 mm rainfall|
|Mean annual rainfall||760||1520||mm; lower/upper limits|
Soil TolerancesTop of page
Natural enemiesTop of page
Notes on Natural EnemiesTop of page The aphid Liosomaphis berberidis Kalt. occurs on B. thunbergii in Poland and the injuries caused by their feeding significantly lowered the ornamental value of plants (Jaskiewicz et al., 2001) and the species has also been found on Mahonia aquifolium (Labanowski, 1990). Several fairly severe infestations by Arge berberidis have been observed in the Netherlands and larvae from defoliated B. thunbergii were seen to migrate to nearby Mahonia aquifolium and complete their development (Frankenhuyzen and Blommers, 2000). Two eryophyid mites, Eriophyes caliberberis and Aceria sp. nov., have been found on B. thunbergii in Poland (Soika and Labanowski 1998). Kakishima and Sato (1979) report the finding of the aecial stage of the fungus Puccinia graminis on B. thunbergii in its native range in Japan.
Means of Movement and DispersalTop of page Birds often feed on the fruit, which results in effective seed dispersal, and a variety of mammals can also contribute to spread from feeding. The effects of passage through the digestive tracts of animals have not been investigated but are expected to be positive. Long-distance dispersal of B. thunbergii is by means of intentional introductions, as the species is still traded as an ornamental plant, multiplied and sold commercially through normal retail outlets, mail order companies and via the internet.
Pathway VectorsTop of page
|Clothing, footwear and possessions||Intentional/unintentional transport of seeds||Yes|
|Containers and packaging - wood||Unintentional transport of seeds||Yes|
|Land vehicles||Unintentional transport of seeds||Yes|
|Soil, sand and gravel||Unintentional transport of seeds||Yes|
Plant TradeTop of page
|Plant parts liable to carry the pest in trade/transport||Pest stages||Borne internally||Borne externally||Visibility of pest or symptoms|
|Fruits (inc. pods)||seeds|
|Growing medium accompanying plants||seeds|
|True seeds (inc. grain)||seeds|
|Plant parts not known to carry the pest in trade/transport|
|Stems (above ground)/Shoots/Trunks/Branches|
Impact SummaryTop of page
|Fisheries / aquaculture||None|
ImpactTop of page B. thunbergii is a host for aphids, different genera of mildews and other fungal pathogens; infested plants can be a threat to cultivated plants from yield reductions due to increased disease outbreaks. Massive growth of bushes on field margins can hamper tillage and work on cultivated land and thereby increase agricultural production costs.
Environmental ImpactTop of page B. thunbergii is shade tolerant and has invaded closed canopy forests, such as in parts of north-eastern USA (Webb et al., 2000). As deer do not feed on it, B. thunbergii has become the dominant understorey plant in some heavily browsed forests. Research in New Jersey, USA, has documented increased soil pH and a reduced litter layer in forests heavily colonized by B. thunbergii and Japanese stiltgrass (Microstegium vimineum). Successful establishment of B. thunbergii can have significant effects on the microbial community of the soil and can significantly change soil biological and chemical characteristics. This may be a trigger for further invasion by other alien species (Kourtev et al., 2002; Kourtev et al., 2003).
Impact: BiodiversityTop of page Kourtev et al. (1998) found that areas invaded by B. thunbergii and Microstegium vimineum had fewer oaks in the canopy, and reduced numbers of native understorey shrubs (Vaccinium spp.). The ability of forest reserves to act as a refuge for native plant species is now threatened by the spread of B. thunbergii where it is present (Ehrenfeld, 1997). However, B. thunbergii bushes are also used by birds for nesting, as it protects them from predation and the berries present a good food resource, thus offering a potential positive impact for native fauna.
Social ImpactTop of page The spines of B. thunbergii present a certain risk to human health, as they are very hard and prone to breaking off under the skin, creating a blister-like, slowly healing wound.
Risk and Impact FactorsTop of page Invasiveness
- Proved invasive outside its native range
- Highly adaptable to different environments
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Highly mobile locally
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Negatively impacts agriculture
- Negatively impacts human health
- Reduced native biodiversity
- Competition - monopolizing resources
- Pest and disease transmission
- Produces spines, thorns or burrs
- Highly likely to be transported internationally deliberately
- Difficult to identify/detect as a commodity contaminant
UsesTop of page The principal use of B. thunbergii is for ornamental and landscaping purposes. It can be planted in rows and pruned and sheared to form a barrier hedge in private gardens or public parks and other public spaces such as around car parks, etc., and it is also often mass planted as a ground cover (Gilman, 1999).
Uses ListTop of page
- Host of pest
Similarities to Other Species/ConditionsTop of page Common barberry (Berberis vulgaris L.) is in its general appearance similar to B. thunbergii, but it has sharply toothed leaf margins, and spines that are often triple-pronged. In contrast to the sessile, umbellate inflorescence of B. thunbergii, B. vulgaris has a racemate inflorescence. B. vulgaris is less shade tolerant as compared to B. thunbergii, and its fruits contain more juice. Berberis x ottawensis Schneid. is a hybrid of B. thunbergii and B. vulgaris. It has a varying number of spines (1-3), a subumbellate-racemate inflorescence, entire leaf margins and dry fruit (Brunelle and Lapin, 1996; IPANE 2001). American barberry (Berberis canadensis P. Mill) grows in dry woods of bluffs and has sharply toothed leaves and triple-pronged spines.
Prevention and ControlTop of page Cultural Control
Deer avoid B. thunbergii and browse surrounding vegetation instead, thus their presence will increase the competitive advantage of this plant. Restricting the access of deer and other grazing mammals by fencing should aid in the regeneration of palatable plant species and possibly limit the spread of B. thunbergii, though no studies have been undertaken in this regard.
Mechanical control is effective. The entire bush and associated roots should be uprooted with a suitable tool (hoe, spade, weed wrench or mattock). Plants produce leaves quite early in spring and can therefore be distinguished easily from other shrubby vegetation. If plants have fruit or seeds present, care should be taken not to disperse them. Mowing and cutting, only possible for initial small populations, can reduce seed formation but regrowth will occur.
A foliar spray of glyphosate is effective, either alone or in combination with triclopyr, but as far as possible, mechanical control should be preferred. Also, plants may be cut, followed by treatment of cut stumps with glyphosate or triclopyr; this can be carried out at any time except when the ground is frozen (Bargeron et al., 2003).
No biological control options are currently known.
ReferencesTop of page
Anon., 1988. 'Crimson velvet' barberry quarantine in force. American Nurseryman, 167(12):13.
Bargeron CT; Moorhead DJ; Douce GK; Reardon RC; Miller AE, 2003. Invasive Plants of the Eastern US: Identification and Control. Morgantown, USA: USDA Forest Service - Forest Health Technology Enterprise Team, FHTET-2003-08.
Brunelle H; Lapin B, 1996. Berberis thunbergii, Japanese barberry. Invasive Plant Fact Sheet. http://tncweeds.ucdavis.edu/moredocs/berthu01.pdf.
Böcker R; Dirk M, 1998. Distribution and spreading of alien trees and shrubs in south western Germany and contributions to germination biology. In: Starfinger U, Edwards K, Kowarik I, Williamson M, eds. Plant Invasions: Ecological Mechanisms and Human Responses. Leiden, The Netherlands: Backhuys Publishers, 285-297.
Cadic A, 1992. Breeding for ever-red barberries (Berberis spp.). Acta Horticulturae, 320:85-90.
Davis OH, 1927. Germination and early growth of Cornus florida, Sambucus canadensis, and Berberis thunbergii. Botanical Gazette, 84:225-263.
Ehrenfeld JG, 1997. Invasion of deciduous forest preserves in the New York metropolitan region by Japanese barberry (Berberis thunbergii DC.). Journal of the Torrey Botanical Society, 124(2):210-215; 17 ref.
Ehrenfeld JG, 1999. Structure and dynamics of populations of Japanese barberry (Berberis Thunbergii DC.) in deciduous forests of New Jersey. Biological Invasions, 1(2/3):203-213.
Gilman EF, 1999. Berberis thunbergii. Fact Sheet FPS-66. Institute of Food and Agricultural Sciences, University of Florida, USA: Environmental Horticulture Department, Florida Cooperative Extension Service.
Hartvig P, 2002. Escaped woody garden plants - a problem in Danish nature? Dansk-Dendrologisk Arsskrift, 20:19-28.
Henderson L, 2001. Alien Weeds and Invasive Plants. Plant Protection Research Institute Handbook No. 12. Cape Town, South Africa: Paarl Printers.
Hosking JR, 2003. NSW Agriculture and CRC for Weed Management Systems. Tamworth, Australia. http://nb.au.com/nswweedsoc/January2003/2.htm.
Hämet-Ahli L; Suominen J; Ulvinen T; Uotila P, 1998. Flora of Finland. Edition 4. Helsinki, Finland: Finnish Museum of Natural History.
IPANE, 2001. Invasive Plant Atlas of New England. Catalog of Species. Rhamnus cathartica (Common buckthorn , European buckthorn). http://webapps.lib.uconn.edu/ipane/browsing.cfm?descriptionid=24.
Knox GW; Hamilton DF, 1982. The long-term effect of light intensity on established woody plants. American Nurseryman, 156(9):83-85.
Koh S; Watt TA; Bazely DR; Pearl DL; Tang M; Carleton TJ, 1996. Impact of herbivory of white-tailed deer (Odocoileus virginianus) on plant community composition. Aspects of Applied Biology, No. 44:445-450; 21 ref.
Kourtev PS; Ehrenfeld JG; Huang WZ; Wieder RK; Novak M; Cerny J, 1998. Biogeochemical investigations at watershed, landscape, and regional scales. Proceedings of BIOGEONOM, TheThird International Symposium on Ecosystem Behavior, Villanova University. Water, Air, and Soil Pollution, 105(1-2):493-501.
Kourtev PS; Ehrenfeld JG; Häggblom, 2002. Exotic plant species alter the microbial community structure and function in the soil. Ecology, 83(11):3152-3166.
Kourtev PS; Ehrenfeld JG; Häggblom, 2003. Experimental analysis of the effect of exotic and native plant species on the structure and function of soil microbial communities. Soil Biology and Biochemistry, 35(7):895-905.
Labanowski G, 1990. Pests of ornamental plants: the barberry aphid Liosomaphis berberidis (Kaltenbach) syn. Aphis berberidis Kalt. Ochrona Roslin, 34(6):24.
Monk R; Peterson HB, 1962. Tolerance of some trees and shrubs to saline conditions. Proceedings of the American Society of Horticultural Science, 81:556-561.
Randall; JM; Marinelli J, 1996. Invasive Plants: Weeds of the Global Garden. Brooklyn, New York, USA: Brooklyn Botanic Garden Publications.
Rhoads AF; Block TA, 2000. The Plants of Pennsylvania: An Illustrated Manual. Philadelphia, USA: University of Pennsylvania Press.
RHS, 1989. The Royal Horticultural Society Gardeners' Encyclopaedia of Plants and Flowers. London, UK: Dorling Kindersley.
Royal Botanical Gardens Canada, 2003. Invasive Plants List. Canadian Botanical Conservation Network, Hamilton, Ontario, Canada. http://www.rbg.ca/cbcn/en/invasives/i_list.html.
Shapiro DK; Anikhimovskaya LV; Narizhnaya TI; Vereskovskii VV, 1983. Chemical characteristics of fruits of some Berberis species introduced into the Belorussian SSR. Rastitel'nye-Resursy, 19(1):84-89.
Silander JA; Klepeis M, 1999. The invasion ecology of Japanese barberry (Berberis thunbergii) in the New England landscape. Biological Invasions, 1(2/3):189-201.
Terabayashi S, 1987. Seedling morphology of the Berberidaceae. Acta Phytotaxonomica et Geobotanica 38(0):63-74.
USDA-ARS, 2003. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
USDA-NRCS, 2002. The PLANTS Database, Version 3.5. National Plant Data Center, Baton Rouge, USA. http://plants.usda.gov.
Wittman H; Pilsl P, 1997. Reports on the flora of the Province Salzburg. Linzer Biologische Beiträge, 29(1):385-506.
Distribution MapsTop of page
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