Japanese barberry

What it looks like

A dense, spiny shrub of the barberry family, usually 3 to 6 feet tall, native to Japan and now invasive (NC State; Plant Invaders of Mid-Atlantic Natural Areas). Its brown, deeply grooved, zigzag branches carry spines at the leaf clusters, usually single (NC State; Penn State Extension) and sometimes three-pronged (Plant Invaders of Mid-Atlantic Natural Areas), and the inner bark is yellow. The small leaves are paddle- or spoon-shaped with smooth edges and grow in clusters; garden cultivars may have red, purple or yellow leaves (Plant Invaders of Mid-Atlantic Natural Areas; Penn State Extension; University of Maryland Extension). The fruits are glossy, bright red, oval berries 1/4 to 1/3 inch long that dangle from the stems singly or in small clusters and hang on into winter (NC State; Penn State Extension; Plant Invaders of Mid-Atlantic Natural Areas). The flesh is dry (US Forest Service; Plant Invaders of Mid-Atlantic Natural Areas) and very sharp-tasting when fresh (Nature’s Restaurant). Practical Self Reliance, a foraging site, calls Japanese barberries edible but less tasty than common barberry, and a bit bitter, but not too bad. Fernald & Kinsey (1958) called the berries dry and inedible.

Safety

NC State lists no poison warning for Japanese barberry, and the fruit is not among the poisonous parts it lists for related barberries. An Ask Extension answer from Ohio calls Japanese barberry mildly toxic to people and animals, without naming a part. The roots and bark are another matter: the US Forest Service says Japanese barberry roots are rich in alkaloids, including berberine, and NC State lists the bark, leaves, roots and sap of common, American and wintergreen barberries as poisonous (low severity: stomach upset, nausea, vomiting and diarrhea), naming berberine as the toxic principle. Eat only the berries. In a related barberry grown for its fruit, the root held about 200 times more berberine than the fruit (PLOS One study of Berberis integerrima). Memorial Sloan Kettering Cancer Center says berberine should be avoided by those who are pregnant or breastfeeding, because it may worsen jaundice in infants, and a review of barberry and berberine toxicity says they should be used with caution in pregnancy, in newborns and in people with G6PD deficiency (Iranian Journal of Basic Medical Sciences); no source checked measured berberine in Japanese barberry fruit. Toxic lookalike: burning bush (winged euonymus), whose red fruit looks very similar, ripens at the same time and grows in the same places (Nature’s Restaurant). Burning bush has no thorns, usually has corky wings along its stems, and its fruit sits in a capsule that splits to show orange-red seeds (Nature’s Restaurant; NC State); NC State says all its parts are poisonous, though toxic only if large quantities are eaten. Nature’s Restaurant’s rule: if a barberry-like shrub has no thorns, do not eat the fruit. NC State lists low cotoneasters among the plants often confused with Japanese barberry, and the University of Utah’s poison control center lists cotoneaster berries as poisonous; bearberry cotoneaster’s red berry has a five-pointed star at its tip, and rockspray cotoneaster’s branchlets are arranged in a fishbone pattern (NC State). Common and American barberries look very similar but have toothed leaf edges and three-pronged spines (Plant Invaders of Mid-Atlantic Natural Areas; Penn State Extension); their tart red berries are edible (Nature’s Restaurant; NC State), but common barberry is rare in Maryland and American barberry does not grow wild there (University of Maryland Extension). Common and American barberries are not recorded near DC. Wintergreen barberry is evergreen, with sharply toothed leaves, three spines at each node and bluish-black fruit (NC State). Hawthorns also have thorns and red fruit but are not poisonous (Nature’s Restaurant); they are trees with thorns 1 to 3 inches long (NC State). Wear thick gloves and sturdy clothing (Plant Invaders of Mid-Atlantic Natural Areas): Penn State Extension says the spine tips are finer than a hypodermic needle and break down very slowly under the skin. Barberry thickets favor black-legged ticks, which can carry the bacterium that causes Lyme disease (University of Maryland Extension; Plant Invaders of Mid-Atlantic Natural Areas). Nature’s Restaurant suggests a DEET-based repellent, checking yourself and washing your clothes after picking, or picking in winter. Japanese barberry is a common herbicide target: Penn State Extension recommends foliar sprays of glyphosate or triclopyr, and Montgomery Parks and Arlington County treat invasive plants in their parks with herbicide. Avoid shrubs that may have been sprayed.

Lookalikes

• Burning bush (winged euonymus) Euonymus alatus toxic

  Named by Nature’s Restaurant as the shrub whose fruit looks very similar to barberry and is ripe at the same time, often in the same places. Burning bush has no thorns, usually has corky wings along its stems, and its fruit is not in hanging clusters; a pair of small maple-key-like parts sits over the fruit (Nature’s Restaurant). NC State describes the fruit inside a red, pink, ivory or yellow capsule that splits to show orange-red seeds and the stems with 2 to 4 corky wings, and says all parts are poisonous, though toxic only if large quantities are eaten (low severity); Nature’s Restaurant says the fruit is not outright poisonous but not generally accepted as edible. Japanese barberry has spines at the leaf clusters (NC State). Nature’s Restaurant: if a barberry-like shrub has no thorns, do not eat the fruit.

  • Barberries (Nature’s Restaurant: A Complete Wild Food Guide) Nature’s Restaurant
  • Euonymus alatus (Burning Bush) NC State Extension Gardener Plant Toolbox
  • Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant Toolbox

• Low cotoneasters (bearberry, rockspray and willowleaf cotoneaster) Cotoneaster dammeri, C. horizontalis, C. salicifolius toxic

  NC State lists these landscape cotoneasters among plants often confused with Japanese barberry. The University of Utah’s poison control center lists cotoneaster berries as poisonous. Bearberry cotoneaster is a low, prostrate evergreen whose red berry has a five-pointed star at its tip, and rockspray cotoneaster’s stiff branchlets are arranged in a fishbone pattern (NC State); Japanese barberry has a single spine at each node and smooth-edged, spoon-shaped leaves in clusters (NC State).

  • Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant Toolbox
  • Cotoneaster (Poisonous Plant Guide) University of Utah Health Poison Control Center
  • Cotoneaster dammeri (Bearberry Cotoneaster) NC State Extension Gardener Plant Toolbox
  • Cotoneaster horizontalis (Rockspray Cotoneaster) NC State Extension Gardener Plant Toolbox

• Common barberry (European barberry) Berberis vulgaris harmless (may be edible)

  A close lookalike (Plant Invaders of Mid-Atlantic Natural Areas; Penn State Extension): common barberry has three-pronged spines and toothed leaf edges, where Japanese barberry has single spines and smooth leaf edges (Penn State Extension; Nature’s Restaurant). Its red berries are edible and cultivated in Iran (Nature’s Restaurant). NC State lists its bark, leaves, roots and sap, not its fruit, as poisonous. The University of Maryland Extension says it is rare in Maryland. Not recorded near DC (no research-grade iNaturalist sightings within 25 km).

  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Japanese Barberry (updated September 9, 2025) Penn State Extension
  • Barberries (Nature’s Restaurant: A Complete Wild Food Guide) Nature’s Restaurant
  • Berberis vulgaris (Common Barberry) NC State Extension Gardener Plant Toolbox
  • Japanese Barberry (revised January 2026) University of Maryland Extension
  • api.inaturalist.org/v1/observations/species_counts

• American barberry (Allegheny barberry) Berberis canadensis harmless (may be edible)

  A native lookalike (Plant Invaders of Mid-Atlantic Natural Areas; Penn State Extension) with leaf edges that have teeth alternating with smooth stretches, unlike the completely smooth edges of Japanese barberry (Plant Invaders of Mid-Atlantic Natural Areas), and three-parted spines (NC State). NC State describes small oblong red berries with a tart flavor and lists its bark, leaves, roots and sap, not its fruit, as poisonous. It does not grow wild in Maryland (University of Maryland Extension) and Plant Invaders says it is absent from, or rare in, much of the mid-Atlantic. Not recorded near DC (no research-grade iNaturalist sightings within 25 km).

  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Japanese Barberry (updated September 9, 2025) Penn State Extension
  • Berberis canadensis (American Barberry) NC State Extension Gardener Plant Toolbox
  • Japanese Barberry (revised January 2026) University of Maryland Extension
  • api.inaturalist.org/v1/observations/species_counts

• Wintergreen barberry Berberis julianae harmless (may be edible)

  Named as a lookalike by Plant Invaders of Mid-Atlantic Natural Areas (three-pronged spines, rounded clusters of yellow flowers). It is evergreen, with sharply toothed leaves, three spines at each node and bluish-black fruit (NC State), unlike Japanese barberry’s red berries. NC State lists its bark, leaves, roots and sap, not its fruit, as poisonous; no source checked treats the fruit as food.

  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Berberis julianae (Wintergreen Barberry) NC State Extension Gardener Plant Toolbox

• Hawthorns Crataegus spp. harmless (may be edible)

  Nature’s Restaurant notes that a thorny shrub with red fruit could be a hawthorn, which is not poisonous. Washington hawthorn is a tree 25 to 30 feet tall with thorns 1 to 3 inches long and clusters of red fruit with edible flesh (NC State); Japanese barberry is a shrub usually 3 to 6 feet tall (NC State).

  • Barberries (Nature’s Restaurant: A Complete Wild Food Guide) Nature’s Restaurant
  • Crataegus phaenopyrum NC State Extension Plant Toolbox
  • Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant Toolbox

Safety flags

• Handling hazard (moderate)

  thorns/prickles: Penn State Extension says the spine tips are finer than the point of a hypodermic needle and break down very slowly under the skin; Plant Invaders of Mid-Atlantic Natural Areas advises thick protective gloves and sturdy clothing. Barberry thickets also favor black-legged ticks, carriers of Lyme disease (University of Maryland Extension; Plant Invaders of Mid-Atlantic Natural Areas).

  • Berberis thunbergii (Zouhar, K., 2008), Fire Effects Information System USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory
  • Berberis vulgaris (Common Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis canadensis (American Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis julianae (Wintergreen Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant Toolbox
  • Japanese Barberry (updated September 9, 2025) Penn State Extension
  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Japanese Barberry (revised January 2026) University of Maryland Extension

• Spray risk

  Listed invasive (Virginia DCR Medium rank; Maryland prohibited) and a standard herbicide target: Penn State Extension calls foliar treatment with a backpack sprayer the most effective means for low to moderate densities (glyphosate or triclopyr), the US Forest Service and Plant Invaders of Mid-Atlantic Natural Areas describe systemic herbicide treatment, and Montgomery Parks and Arlington County treat invasive plants in their parks with herbicide.

  • Japanese Barberry (updated September 9, 2025) Penn State Extension
  • Berberis thunbergii (Zouhar, K., 2008), Fire Effects Information System USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory
  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Pesticide use and notification (park treatment schedule) Montgomery Parks (M-NCPPC)
  • Budget guidance: invasive plants (Arlington County Park and Recreation Commission, November 2025) Arlington County, Virginia
  • Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural Heritage

• Toxic parts

  The US Forest Service says Japanese barberry roots are rich in alkaloids, including berberine, and NC State lists the bark, leaves, roots and sap of common, American and wintergreen barberries as poisonous (low severity: stomach upset, nausea, vomiting, diarrhea), with berberine as the toxic principle. NC State lists no poison for Japanese barberry itself and no barberry fruit as poisonous.

  • Berberis thunbergii (Zouhar, K., 2008), Fire Effects Information System USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory
  • Berberis vulgaris (Common Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis canadensis (American Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis julianae (Wintergreen Barberry) NC State Extension Gardener Plant Toolbox
  • Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant Toolbox
  • Japanese Barberry (updated September 9, 2025) Penn State Extension
  • Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)
  • Japanese Barberry (revised January 2026) University of Maryland Extension

ID risk

Careful

Why

Burning bush, whose red fruit looks very similar and ripens at the same time (Nature’s Restaurant), is poisonous (NC State) but has no thorns, usually has corky-winged stems and fruit in a capsule that splits to show orange-red seeds (Nature’s Restaurant; NC State). Low cotoneasters, which NC State lists as often confused with Japanese barberry, have berries the University of Utah’s poison control center lists as poisonous; bearberry cotoneaster’s berry has a five-pointed star at its tip, while Japanese barberry has a single spine at each node (NC State). The roots and bark of barberries carry berberine (US Forest Service; NC State). Common and American barberries (edible; not recorded near DC), wintergreen barberry and hawthorns are harmless lookalikes.

Handling hazards

Thorns (moderate)

Soil risk

low

Field safety for every outing (poison ivy, ticks, soil, and more)

When to pick

The University of Maryland Extension says the berries ripen in autumn and persist, until eaten by wildlife, into winter, and NC State gives glossy red berries in the fall, persisting into winter. Plant Invaders of Mid-Atlantic Natural Areas says the berries mature from July to October and persist through the winter. Nature’s Restaurant, an Ontario foraging site, says the berries ripen in the fall and stay good right into spring. In a Connecticut study most of the fruit was gone from the shrubs by January (US Forest Service), so how long the berries last varies from place to place. No source gives a best month for the DC area.

Where to look

Woods, woodland edges and old fields, and planted as a hedge in yards; logged most in Rock Creek Park, Huntley Meadows Park, Rock Creek Regional Park, Rockville Civic Center Park and Wheaton Regional Park, where picking is not allowed or the rules were not checked. The C&O Canal allows edible fruits generally but sets no limit for Japanese barberry, so it is ambiguous there (ask the park); otherwise pick in Virginia state parks such as Mason Neck, or from private shrubs with the owner’s permission.

Habitats

street & yard trees (planted), disturbed ground & waste places, old fields & meadows, woods edges, trailsides & thickets, floodplain & stream-valley forest, wetlands, marshes & pond edges

Most-logged places

None of the most-logged places allows picking.

Ask first: rules unclear or not checked

• Rockville Civic Center Park

  46 sightings · Legal to pick: unknown · see them on iNaturalist

  Picking rules not checked.

Where you may pick

Invasive: Virginia’s Department of Conservation and Recreation ranks Japanese barberry Medium on its invasive plant list, and it is on the Maryland Department of Agriculture’s prohibited invasive plant list. Maryland’s regulations say no one may transport or introduce any living part of a prohibited invasive plant in the state (Code of Maryland Regulations 15.06.04.04). Do not plant it or carry its berries into new areas: turkeys, grouse and other wildlife spread the seeds in their droppings (Plant Invaders of Mid-Atlantic Natural Areas). C&O Canal NHP’s compendium says edible fruits, nuts and berries may be gathered by hand for personal use but sets limits only for listed species; this one is not listed, so its status there is ambiguous: confirm with the park. Not on Prince William Forest Park’s list. Virginia state park rules allow edible fruits and berries to be collected for personal use. Rock Creek Park (which also runs Glover-Archbold, Battery Kemble, the western and northern Civil War Defenses forts and many small DC reservations) bans gathering any fruit, nut, berry or seed. Pick on private land only with the owner’s permission.

Best legal spot

Mason Neck State Park (6 obs)

• C&O Canal NHP (incl. Great Falls MD, trail-side only)

  Allowed: ambiguous · no limit set for this species; by hand, personal use; confirm with the park

  C&O 2026 compendium 2.1(c)(1): 'Edible fruits, nuts, berries, and mushrooms may be gathered by hand for personal use or consumption.' The limits table that follows does not list this species. 36 CFR 2.1(c)(1) requires designating 'certain' fruits, so the narrower reading (listed species only) is also possible. Confirm with the park.

• Virginia State Parks

  Allowed: yes · personal/individual use only; no quantity set (state parks within ~50 km: Mason Neck, Leesylvania); individual parks may post closures

  4VAC5-30-50 bars gathering any plant without a permit, except that edible fruits, berries, fungi or nuts may be collected for personal or individual use; Japanese barberry is an edible fruit

Every park’s rules

Ways to use it

• jam: cook the berries until soft, press them through a food mill or fine strainer to remove the seeds, then cook the pulp with sugar until it gels (Practical Self Reliance)
• jams and jellies made without added pectin, because barberries are very high in pectin (Nature’s Restaurant)
• in rice dishes and other meals, used like the European barberries sold dried as zereshk for Persian cooking (Nature’s Restaurant)
• eat raw: very sharp-tasting when fresh (Nature’s Restaurant) and a bit bitter (Practical Self Reliance)
• harvest in winter, when the berries still hang on the shrubs, to lower the tick risk (Nature’s Restaurant), and wear thick gloves against the spines (Plant Invaders of Mid-Atlantic Natural Areas)

Keeping

Leave them on the shrub until needed, then use within 1-3 days of picking or freeze or dry them; keep jam refrigerated or frozen, because there is no tested canning process.

Use within

within a few days

Keeps fresh

The berries hang on the shrub into winter (University of Maryland Extension; Penn State Extension), so pick as needed. Once picked: refrigerate unwashed and use within 1-3 days (general guidance for berries).

Canning

no tested recipe: refrigerate or freeze, don’t can

Keeping basis

general guidance for its type

Ways to keep it

• Dry as researched: dry/dehydrate; canning: n/a (not shelf-canned)

  In the Middle East barberries are usually dried so they can be used year round (Practical Self Reliance; Nature’s Restaurant). Store dried fruit airtight in a cool, dark place (general guidance for dried fruit, NCHFP).

• Freeze as researched: freeze; canning: n/a (not shelf-canned)

  Tray-freeze whole berries, then pack them (general guidance for berries, NCHFP).

• Jam/jelly as researched: jam/jelly; canning: no tested recipe — refrigerate or freeze

  Practical Self Reliance: cook until soft, run through a food mill or fine strainer to remove the seeds, measure the pulp, add sugar (1:1, or 3/4 part sugar to 1 part pulp for a tarter jam) and cook until it gels; no pectin is needed (Nature’s Restaurant). No NCHFP or extension-tested canning process exists for barberry, so refrigerate or freeze the jam.

Nutrition

Not researched: in October 2026, only the calendar’s plants of the month and chicory leaves were researched.

Native or not

Plant Invaders of Mid-Atlantic Natural Areas says Japanese barberry is hybridizing with common barberry to create the hybrid B. × ottawensis. USDA PLANTS lists it as introduced in the lower 48. Maryland exempts one cultivar, 'UCONNBTB048' (Lemon Glow), from its prohibited list.

Origin

non-native

Native range

Japan (NC State; Plant Invaders of Mid-Atlantic Natural Areas)

Invader credit

★★★

Virginia invasive rank

Medium

Maryland invasive status

Prohibited (MDA)

How the ratings were set

Find

Everywhere Estimate 1,929 = 1,688 research-grade iNaturalist sightings within 25 km + 43 needs-ID sightings counted at 46% (1,688 of the 3,645 research-grade Berberis sightings here are Japanese barberry) + 221 'cultivated' (planted) sightings (rule A); that is tier 1 by count (rule B). Rule C (everyday place) is met: Nature’s Restaurant says "This is the most common one you will find in parks, and as an ornamental in gardens and front yards". Rule D does not apply: the Digital Atlas of the Virginia Flora says Japanese barberry is "rare in the Coastal Plain", but the same atlas calls it "Frequent in the mountains and Piedmont", and Virginia’s Piedmont takes in part of the circle. Final tier 1.

Effort

Grab & eat Pick the berries one by one from the spiny stems (wear gloves) and eat them raw: tart and a bit bitter (Practical Self Reliance); jam, with the cooked berries pressed through a food mill to remove the seeds, is a 3.

Sources

39 sources, each linked to the original.

1. COMAR 15.06.04.04 Prohibited Plant Prohibitions and Approvals (Code of Maryland Regulations; final action 53:14 Md. R. 25-186-F) Maryland Division of State Documents (text of state regulation, Maryland Department of Agriculture)Backs up: picking rules
2. C&O Canal NHP Superintendent’s Compendium (2026) National Park ServiceBacks up: picking rules
3. Rock Creek Park Superintendent’s Compendium National Park ServiceBacks up: picking rules
4. Prince William Forest Park Superintendent’s Compendium National Park ServiceBacks up: picking rules
5. 4VAC5-30-50. Flowers, plants, minerals, etc. (Virginia State Parks Regulations) Virginia Administrative Code (Virginia General Assembly, LIS)Backs up: picking rules
6. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: picking rules, native or invasive status
7. Maryland Prohibited Invasive Plant Law and Regulations (Maryland Prohibited Invasive Plant List, updated January 2026) Maryland Department of Agriculture, Plant Protection & Weed ManagementBacks up: picking rules, native or invasive status
8. Foraging Barberry (Berberis) (Ashley Adamant) Practical Self RelianceBacks up: description, uses, storage, keeping
9. iNaturalist research-grade observations of Berberis thunbergii within 25 km of downtown DC iNaturalistBacks up: findability
10. Annotated Checklist of the Vascular Plants of the Washington-Baltimore Area, Part I (Shetler & Orli, 2000) Smithsonian Institution, National Museum of Natural HistoryBacks up: habitat
11. Berberis thunbergii (Japanese Barberry) (Digital Atlas of the Virginia Flora) Virginia Botanical Associates (Digital Atlas of the Virginia Flora)Backs up: habitat, findability
12. How to Preserve Berries Utah State University ExtensionBacks up: keeping
13. Packaging and Storing Dried Foods National Center for Home Food Preservation (University of Georgia)Backs up: keeping
14. Dry or Tray Packing for Fruits National Center for Home Food Preservation (University of Georgia)Backs up: keeping
15. USDA PLANTS Database: Berberis thunbergii (BETH), native status USDA NRCSBacks up: native or invasive status
16. Non-Native Invasive Terrestrial Plant Species in the State of Maryland (updates approved through the April 18, 2024 MISC meeting) Maryland Invasive Species CouncilBacks up: native or invasive status
17. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
18. Berberis vulgaris (Common Barberry) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
19. Berberis canadensis (American Barberry) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
20. Berberis julianae (Wintergreen Barberry) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
21. Euonymus alatus (Burning Bush) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
22. Cotoneaster dammeri (Bearberry Cotoneaster) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
23. Crataegus phaenopyrum (Washington Hawthorn) NC State Extension Gardener Plant ToolboxBacks up: safety, effort & ID risk, safety details
24. Cotoneaster (Poisonous Plant Guide) University of Utah Health Poison Control CenterBacks up: safety, effort & ID risk, safety details
25. Cotoneaster horizontalis (Rockspray Cotoneaster) NC State Extension Gardener Plant ToolboxBacks up: safety, safety details
26. A comparative study of alkaloid and phenolic compounds in different organs and tissues of Berberis integerrima (Zhaleh et al., PLOS One, 2025) PLOS One (peer-reviewed; PubMed Central)Backs up: safety, safety details
27. Berberine (About Herbs, Botanicals & Other Products) Memorial Sloan Kettering Cancer CenterBacks up: safety, safety details
28. Toxicology effects of Berberis vulgaris (barberry) and its active constituent, berberine: a review (Rad, Rameshrad & Hosseinzadeh, 2017) Iranian Journal of Basic Medical Sciences (peer-reviewed; PubMed Central)Backs up: safety, safety details
29. Is this the right info on this plant? (#848920) Ask ExtensionBacks up: safety, safety details
30. Pesticide use and notification (park treatment schedule) Montgomery Parks (M-NCPPC)Backs up: safety, safety details
31. Budget guidance: invasive plants (Arlington County Park and Recreation Commission, November 2025) Arlington County, VirginiaBacks up: safety, safety details
32. iNaturalist research-grade observations of Berberis thunbergii within 25 km of Washington, DC, by month (fruiting) iNaturalistBacks up: season
33. iNaturalist research-grade observations of Berberis thunbergii within 25 km of Washington, DC, by week (fruiting) iNaturalistBacks up: season
34. Berberis thunbergii (Zouhar, K., 2008), Fire Effects Information System USDA Forest Service, Rocky Mountain Research Station, Fire Sciences LaboratoryBacks up: season, description, habitat, safety
35. Japanese Barberry (revised January 2026) University of Maryland ExtensionBacks up: season, description, habitat, safety, effort & ID risk, keeping, safety details
36. Berberis thunbergii (Japanese Barberry, Thunberg’s Barberry) NC State Extension Gardener Plant ToolboxBacks up: season, description, habitat, safety, native or invasive status
37. Japanese Barberry (updated September 9, 2025) Penn State ExtensionBacks up: season, description, safety, effort & ID risk, keeping, safety details
38. Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022), Japanese barberry, pp. 90-91 Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)Backs up: season, description, uses, habitat, safety, picking rules, native or invasive status
39. Barberries (Nature’s Restaurant: A Complete Wild Food Guide) Nature’s RestaurantBacks up: season, description, uses, habitat, safety, findability, keeping