Regularity: Regularly occurring
Global Range: Southeast United States: Georgia, North Carolina, Tennessee, Virginia, and West Virginia, with scattered, disjunct remnant populations in Illinois, Indiana, Kentucky, and Missouri. Considered extirpated from Alabama.
Comments: Berberis canadensis occurs in open woods, on bluffs and cliffs and along river banks in the eastern and central United States (Gleason and Cronquist 1991, Cook et al. 1987, Fernald 1970, Small 1933). Formerly an inhabitant of savannas and open woodlands, fire suppression has significantly restricted its habitat to sites with shallow soil (such as glades and cliffs) or areas with mowing or other canopy-clearing activities (such as powerline corridors, railroad/road right-of-ways and riverbanks).
The single extant population from Indiana is restricted to steep banks along the Tippecanoe River in the northern part of the state (Homoya 1992). Associated plant species include Besseya bullii, Lithospermum sp. and liverworts (Indiana Natural Heritage Data Center 1989). Prior to eradication efforts, Deam (1940) observed long stretches of the species along the banks of the Tippecanoe River, occupying an area "a few feet back from the edge of the bank and down the slope to high water mark".
Historically, B. canadensis occurred in Maryland in dry, calcareous woodlands, open fields and serpentine barrens (Maryland Natural Heritage Program 1992). No extant populations are known in the state.
In Missouri, B. canadensis is typically found on north-facing, rocky, wooded slopes; along streams; upper ledges or bluffs; exposed upper portions of bluffs on limestone, dolomite or sandstone; and mesic limestone/dolomite cliffs (Smith 1992, Roedner et al. 1978, Holt et al. 1974, University of Minnesota Herbarium (MIN)). Substrate composition usually consists of limestone, dolomite or sandstone with a somewhat basic pH (Smith 1993). Steyermark (1963) stated that the plant appears to be restricted to the edges of limestone bluffs where the soil is leached out, or near the contact point between chert or Roubidoux sandstone with limestone. Associated plant species in Missouri include Campanula rotundifolia, Carpinus caroliniana, Galium boreale ssp. septentrionale, Trautvetteria caroliniensis and Zigadenus elegans (Smith 1992, Steyermark 1963).
Berberis canadensis is found in 19 mountain counties in southwest Virginia (Huber 1993). Occupied habitat includes dry, open woodlands over limestone, dolomite, richer sandstone or shale substrates, rocky and cliffy areas and open areas and glades with naturally thin soil (Ludwig 1993, Ludwig 1992). Associated plant species in glades include Helianthus divaricatus, Juniperus virginiana and Schizachyrium scoparium. In rocky areas it is found with Cercis canadensis, Pellaea atropurpurea and Quercus muehlenbergii (Ludwig 1993).
Two historic populations are known from Georgia, but no recent efforts have been made to relocate them (Patrick 1989). Occupied habitat is described as dry, hard soil on upper, west-facing slopes and dry, rocky woods (Georgia Freshwater and Wetlands Heritage Inventory 1989).
In North Carolina, B. canadensis occurs in the Piedmont on mafic rocks (such as diabase, amphibolite and gabbro) and in the Blue Ridge on calcareous (limestone, dolomite, marble) and mafic rocks (amphibolite). It generally occurs in glade, open woodland, bluff or cliff situations (North Carolina Natural Heritage 1993, Weakley 1993, University of Minnesota Herbarium (MIN)). The species was historically found in fire-maintained habitats which kept the canopy open, but is now restricted to sites with very shallow soil or with mowing maintenance (right-of-ways, powerline corridors, etc.). Due to its association with mafic and calcareous rocks (uncommon to rare in the state), B. canadensis is often associated with other rare species. Typical associated plant species include Aquilegia canadensis, Cercis canadensis, Clematis ochroleuca, Desmodium spp., Echinacea laevigata, Matelea decipiens, Parthenium auriculatum, Pycnanthemum spp., Rhus aromatica, Silphium trifoliatum, Solidago rigida, Symphoricarpos orbiculatus and Viburnum rafinesquianum (North Carolina Natural Heritage 1993, Weakley 1993).
In Illinois, B. canadensis is known from a single extant site at the rim of a dry sandstone cliff (Illinois Natural Heritage Division 1992). No extant populations are known from the state (Schwegman 1989). Historic populations occurred on the rim of dry sandstone cliffs and in dry woodlands (Illinois Natural Heritage Division 1992, Mohlenbrock 1975).
No extant populations are known from Kentucky (Kentucky Natural Heritage Program 1993). Historic habitat is listed as limestone woodlands.
Berberis canadensis is known from Pennsylvania by one historic occurrence in the western portion of the state (Pennsylvania Natural Diversity Inventory-West 1993, Kunsman 1992). Habitat for the occurrence was listed as "woods and waste places around abandoned buildings" and "rocky woods" (Pennsylvania Natural Diversity Inventory-West 1993). There is some speculation whether the occurrence was native or was introduced to the site (Kunsman 1992).
Collections at the University of Tennessee-Knoxville Herbarium (TENN) suggest that occupied habitat is relatively open woodlands (Pyne 1994). Collections have been made from wooded slopes, shale slopes, bluffs, terraces along river bluffs and river banks.
Known Pests: American barberry and most other barberries are alternate hosts for wheat rust (Puccinia graminis), a fungus that has caused major losses in certain grain crops here and in Europe (Hill 2003).
Foodplant / parasite
Erysiphe berberidis parasitises Berberis canadensis
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: Extant occurrences in: Indiana (2--1CD, 1D), Illinois (1), Kentucky (2 documented, likely to be more occurrences (White, 1998), Missouri (12), North Carolina (10), Tennessee (4 collections in last 20 years). Ranked S3S4 in Virginia with occurrences in 19 counties.
American barberry is one of the few native shrubs that is not vulnerable to the effects of black walnut toxicity (Hill 2003).
Life History and Behavior
Persistence: PERENNIAL, Long-lived, DECIDUOUS
Molecular Biology and Genetics
Statistics of barcoding coverage: Berberis canadensis
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: There are approximately 50 occurrences known across its range. (Insufficient inventory, particularly in Virginia and South Carolina, may cloud its true abundance.) However, most populations are small and have little reproduction. Further, Berberis canadensis is very threatened range-wide as it is still targeted for eradication by agricultural officials.
Global Short Term Trend: Decline of 10-30%
Comments: The species has declined significantly since settlement due to habitat destruction and eradication efforts. Loss of the natural fire regime and continued eradication efforts suggest that the downward trend is continuing.
Comments: Berberis canadensis (and the majority of barberries) is an alternate host for the black stem rust of wheat, oats, rye barley, and various wild and cultivated grasses (Weakley 1993, Steffey 1985, Rudolf 1974, Steyermark 1963). The U.S. Department of Agriculture and state agriculture offices initiated a comprehensive barberry eradication program in the past to elimiate black stem rust. As a result, numerous populations of this species were destroyed (Weakley 1993, Wiegman 1993, Homoya 1992, Steyermark 1963).
Loss of primary habitat has also played a significant role in the demise of this species. The elimination of the natural fire regime has resulted in the succession of savanna and open woodland habitats into closed-canopy woodlands. Only in sites with extremely shallow soils or areas that are frequently mowed or cleared does B. canadensis persist in any significant populations. Since settlement, much of the available habitat has been destroyed, converted to cultivated fields, land development, and urbanization (Weakley 1993). These threats remain for extant populations.
Grazing is a potential threat to extant populations (Smith 1992, Ludwig 1993). Grazing may serve to maintain the open character of woodlands, but its effects on B. canadensis plants are unknown. In some areas, the plants appear to be grazed by cattle (Smith 1992). Soil compaction and disturbance may negatively impact individual plants and populations.
Competition from exotic plant species (such as Lonicera tatarica and Rhamnus cathartica) is a threat to populations (Ludwig 1993). These species can form dense stands and eliminate ground layer herbaceous and other shrub species, including B. canadensis. Excessive shading and canopy closure in woodlands may be a factor in reducing seed production in the species, as has been noted in Missouri (Smith 1992).
Restoration Potential: The restoration potential of this species is largely unknown. Establishment or augmentation of populations is dependent upon seed germination, but conditions under which germination is triggered are unknown. Given success in germinating seeds, coupled with an active habitat management program designed to maintain open woodland/savanna conditions, restoration should be successful.
Preserve Selection and Design Considerations: Preserve designs should incorporate the requirements of fire management in maintaining suitable, open habitat. Preserve designs should incorporate sufficient area to conduct proper prescribed fire management and allow for a matrix of habitat areas and management units. Smoke planning should also be addressed in the preserve design.
Preserve size should also be a requirement for the long-term protection and viability of the species. Sufficient preserve size should be planned for habitat protection and restoration, and expansion of existing populations into these habitats.
Management Requirements: Berberis canadensis is a species of open woodlands, glades and savannas. Most of these habitats have grown closed with trees and shrubs since the elimination of a natural fire regime. Prescribed fire or selective thinning of the canopy should be conducted in order to increase light levels to the habitat and populations (Weakley 1993).
Managers should work cooperatively with state and federal regulatory agencies and organizations (e.g., USDA and state departments) to reduce or eliminate the effects of continued Berberis eradication efforts (Homoya 1992).
Management Programs: No known management programs are currently in place for the species in any portion of its range.
Monitoring Programs: Monitoring of plants is done by the Indiana DNR, Division of Entomology, for signs of black stem rust as part of eradication efforts.
Contact: Mike Homoya, Ecologist/Botanist, Indiana Natural Heritage Data Center, Division of Nature Preserves, Department of Natural Resources, 402 W. Washington St., Rm. W267, Indianapolis, IN 46204. Telephone: (317) 232-4052.
Populations in Missouri are revisited every several years in order to update their status in the Heritage Database. Most sites were revisited between 1984 and 1990.
Contact: Tim Smith, Botanist, Natural History Division, Missouri Department of Conservation, 2901 W. Truman Blvd., Jefferson, MO 65109. Telephone: (314) 751-4115.
Management Research Programs: No research programs directed at management needs are known at this time.
Management Research Needs: Research regarding the response of this species to fire, canopy thinning and other management activities would allow for better management of populations and habitat (Weakley 1993). There is a need to determine the best habitat for the species and how to best maintain the character of these areas (Smith 1992).
Biological Research Needs: Investigate factors that limit seed production; study the effects of habitat quality and genetic variation within and between populations to assess species' vigor (Smith, 1992). Research is needed to accurately assess the role that B. canadensis plays as a host to stem rust. Does the eradication of extant populations play a significant role in the elimination of the rust? Do eradication efforts pay for themselves? Information along these lines could be used to persuade agents to discontinue eradication efforts.
Comments: The red, fleshy berries of B. canadensis are edible (Small 1933). The plant is often grown for ornamental purposes because of its attractive foliage, flowers and fruit. It is also useful for wildlife food and cover and erosion control. The majority of barberry species are susceptible to black stem rust of wheat. Roots of barberry can be used to obtain a yellow dye. The plants contain an alkaloid called berberine, which is used for medicinal purposes in some areas (Rudolf 1974).
Research on this species has investigated the ultrastructural features of the cortical parenchyma cells in the stamen filaments (Fleurat-Lessard and Millet 1984). The stamen filaments of Berberis canadensis respond to various electrical, mechanical and chemical stimuli by bending. The mature stamens are formed from the reproductive meristem and lack photosynthetic activity and circadian movements. Berberis canadensis contains unusual walls, vascular microfibrils and microfilaments in the stamens. These walls are elastic due to their multiple folded appearance. Changes in the wall in the form of extensions may be linked with IAA, which may alter the fibrillar structure by regulating protein fluxes (Pilet and Roland 1974 as in Fleurat-Lessard and Millet 1984).
Another common name for this species is Alleghany barberry. An illustration of the species can be found in Steyermark (1963). Range distribution maps of the species can be found in the following sources: Missouri (Steyermark 1963), Virginia (Harvill et al. 1986).
Relevance to Humans and Ecosystems
Comments: The primary threat to the survival of Berberis canadensis has been from the U.S. Department of Agriculture (USDA) comprehensive barberry eradication program. American barberry and most other barberries are alternate hosts for wheat rust (Puccinia graminis), a fungus that has caused major losses in certain grain crops here and in Europe (Hill 2003). Four small-grain crops (wheat, oats, barley, and rye) are all potential hosts to the organism causing black stem rust (BSR). Barberry is an alternate host for the organism causing black stem rust (BSR). Breeding varieties of small grains for resistance to BSR began in the United States around 1900 meeting with rapid success from crosses with wheat varieties from Russia and Turkey. By 1938, farmers were
planting resistant wheat varieties in the areas of the United States where BSR had been most destructive and continued to develop new resistant crop varieties. The difficulty with this approach is that while an individual crop variety may be resistant to several races of BSR, there are more than 200 existing races of BSR. The presence of BSR-susceptible barberry bushes providing the opportunity for new hybrid races of BSR to develop complicates the problem further. The use of resistant crops alone would never provide farmers with adequate protection from BSR. With the increasing demand for U.S. wheat, an alternative method of defense against a catastrophe the magnitude of the BSR epidemic of 1916 was needed.
In 1918, the U.S. Department of Agriculture (USDA) initiated a barberry eradication program in
cooperation with 13 north-central States (Colorado, Illinois, Indiana, Iowa, Michigan, Minnesota,
Montana, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin, and Wyoming). In 1935, four
additional states (Missouri, Pennsylvania, Virginia, and West Virginia) joined the program, followed by Washington State in 1944. This time, the program resulted in the destruction of several hundred million susceptible barberry and mahonia bushes in over 700,000 square miles. Although barberry eradication is a cooperative project with State personnel, USDA has always played a leading role. USDA's funding for the barberry eradication program ended in 1980. Although several States continued some barberry eradication activities, the extensive eradication program also ended in 1980 (APHIS no date, Hill 2003).
Stewardship Overview: Management for B. canadensis should include the use of prescribed fire, selective thinning of the canopy or controlled mowing in order to maintain high light levels and eliminate woody plant encroachment. Habitats need protection from urbanization, agricultural activities, destructive recreational activities, land development, indiscriminate pesticide application, excessive grazing and exotic species. Monitoring of occurrences should be conducted frequently to track their status with respect to management activities. Habitat quality should be monitored and an assessment of threats to all populations should be made. Cooperative efforts between state and federal regulatory agencies (e.g., USDA and state departments) should be exercised to reduce or eliminate the effects of continued Berberis eradication efforts. Research is needed to accurately assess the role of B. canadensis as an alternate host to stem rust. Investigations into the reproductive biology, genetic variation, pollination vectors, factors effecting seed production and the response to management activities are also needed.
Berberis canadensis more commonly known as the American Barberry is a member of the family Berberidaceae. Berberis canadensis is the only simple-leaved Berberis indigenous to the United States. The epithet "canadensis" literally means "Canadian" but was often used by 18th-Century botanists to refer to any plants growing in northeastern North America.
Berberis canadensis is a deciduous shrub, which grows, on average 1 meter in height, sometimes reaching as high as 2 meters. It spreads by rhizomes, forming large stands of clones. Rhizomes enable the plant to absorb more nutrients from the soil. This enables the species to grow in relatively dry environments. Stems of Berberis canadensis are hairless, not extensively branched, and range in color from green, purple, red, to brown. Stems also grow in a dimorphic fashion. The leaves on the shrub are arranged in an alternate pattern with petioles 8 mm in length and covered in a white waxy coating known as glaucose. In addition, leaves are thin and smooth and ovate in structure. A seemingly random venation pattern is visible on the underside of the leaves.
Berberis canadensis is indigenous in 13 of the 50 states. B. canadensis has occurs naturally from the Appalachian Mountains from southern Pennsylvania to northern Georgia and Alabama. Scattered populations have also been reported as far west as Missouri.
The species primarily thrives on rocky slopes on the sides of hills and mountains. The species used to be a lot more prevalent in the past, however due to its connection with wheat rust, the United States government has slowly been eradicating the species. It seems that the species has reached an equilibrium with the environment, thus indicating no further expansion of the range. Unlike most plants whose growth is restricted by weather, B. canadensis is primarily restricted by soil composition and habitat openness.
Habitat and Ecology
Berberis canadensis grows in many diverse open environments. It can be found in dry woodlands or on exposed hillside. The species grows in different soils types as well, ranging from basic to slightly acidic and extremely shallow in depth. The soil is well-drained with occasional moisture obtained from seasonal rainfall. Berberis canadensis is perennial, and is associated with a number of plants that grow in its habitat.
Flowers and fruit
Flowers of Berberis canadensis are arranged in a raceme. They are usually 2–5 cm in length and have six petals. The petals are cup-shaped and notched at the tips. In addition, flowers are set in a double row pattern, with one petal sitting on top of another. They range in color from yellow to a dull whitish yellow with a bright green stigma protruding out of the middle. The stamen responds to physical stimuli and bends towards the stigma when a stimulus is present.
The fruit of Berberis candensis are used extensively by many people, and is rich in vitamin C. Historically, it has been known as a major source of nutrition for the indigenous people of southeastern United States. The juicy red berries of the plant can be cooked to make jelly. The juice of the berries is also a sought-after refreshment. Lastly the berries of the B. canadensis are pounded to produce a paste similar to oatmeal. In addition, the berries are sometimes used to make alcoholic beverages.
Native Americans, specifically the Cherokee, have been known to use Berberis canadensis as a remedy for diarrhea. The bark of the plant would be placed in water and then drunk to help alleviate the symptoms. In addition all plants in the Berberidaceae are known to have anti-rheumatic and anti-cancer affects.
- The Plant List
- Flora of North America vol 3
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