Oriental Bittersweet (Celastrus orbiculatus)
Miller, J.H., E.B, Chambliss, N.J. Loewenstein. 2010. A Field Guide for the Identification of Invasive Plants in Southern Forests. General Technical Report SRS-119. Asheville, NC. United States Department of Agriculture, Forest Service. 126 p.
Deciduous, twining and climbing woody vine to 60 feet (20 m) in tree crowns, forming thickets and arbor infestations. Elliptic to round-tipped leaves, axillary dangling clusters of inconspicuous yellowish flowers in spring, and green spherical fruit that split to reveal 3-parted showy scarlet berries in winter.
Woody vine to 4 inches (10 cm) diameter, twining and arbor forming, with many alternate drooping branches growing at angles and eventually becoming straight. Vigorous twigs with sharp bud scale tips. Reddish brown with many raised whitish corky dots (lenticels), often angular or ridged, becoming tan to gray. Branch scars of fruit clusters semicircular, each with a tiny corky shelf projection. Bark dark grayish brown with irregular netted ridges.
Alternate, 1.2 to 5 inches (3 to 12 cm) long. Variable shaped, long tapering tipped when young becoming larger and round tipped when mature. Margins finely blunt toothed. Dark green becoming bright yellow in late summer to fall. Base tapering into 0.4- to 1.2-inch (1- to 3-cm) petiole.
May. Numerous tiny-branched axillary clusters (cymes), each with 3 to 7 inconspicuous orange-yellow flowers. Five petals. Male and female flowers can occur on the same or different plants.
Fruit and seeds
August to January. Dangling clusters of spherical 0.5-inch (1.2 cm) capsules, tipped with a persistent pistil. Green turning yellow orange then tan. In autumn, splitting and folding upward to reveal 3 fleshy scarlet sections, each containing 2 white seeds. Persistent in winter at most leaf axils.
Occurs on a wide range of sites mainly along forest edges. Found as scattered plants to extensive infestations in forest openings, margins, and roadsides as well as in meadows. Shade tolerant with high seed germination under canopies. Colonizes by prolific vines that root at nodes, and seedlings from prolific seed spread mainly by birds, possibly other animals and humans collecting and discarding decorative fruitbearing vines.
Resembles American bittersweet (C. scandens L.), which has only terminal flowers and fruit, leaves usually twice as large but absent among the flowers and fruit, grayish and nonridged twigs, and blunt bud-scale tips. Hybridization occurs between the 2 species. Also resembles grape vines (Vitis spp.) in winter but can be distinguished by persistent scarlet fruit versus grapes.
History and use
Introduced from Asia in 1736. Very showy ornamental with berried vines that are traditionally collected as home decorations in winter, which promotes spread when inappropriately discarded.
Found throughout the region except FL, TX, and OK with frequent and dense infestations in east KY, west NC, and north VA.
- Do not plant. Remove prior plantings, and control sprouts and seedlings. Bag and dispose of plants and fruit in a dumpster or burn.
- Treat when new plants are young to prevent seed formation.
- Pull, cut, and treat when fruit are not present.
- Minimize disturbance within miles of where this plant occurs, and anticipate wider occupation when plants are present before disturbance.
- Repeated cutting to groundline commonly recommended for control, while root sprouts might worsen some infestations.
- Manually pull new seedlings and tree wrench large vines when soil is moist, ensuring removal of all roots. Outlying large vines that remain after treatments will resprout, even under a forest canopy.
- Burning treatments are suspected of having minimal topkill effect due to scant litter.
- Readily eaten by goats while seed spread is possible.
Recommended control procedures
- Thoroughly wet all leaves with one of the following herbicides in water with a surfactant (July to October): Garlon 4, Garlon 3A, or a glyphosate herbicide as a 3-percent solution (12 ounces per 3-gallon mix).
- For stems too tall for foliar sprays, to control vines less than 1-inch diameter, apply Garlon 4 as a 20-percent solution (5 pints per 3-gallon mix) in a labeled basal oil product, vegetable oil, kerosene, or diesel fuel (where permitted); or apply undiluted Pathfinder II as a basal spray to the lower 2 feet of stems. Or cut large stems and immediately treat the cut surfaces with one of the following herbicides in water with a surfactant: Garlon 4 or a glyphosate herbicide as a 25-percent solution (32 ounces per 1-gallon mix). ORTHO Brush-B-Gon, Enforcer Brush Killer, and Vine-X are effective for treating cut-stumps and readily available in retail garden stores (safe to surrounding plants). Winter applications are effective.
- For large vines, make stem injections using Arsenal AC*, Garlon 3A, or a glyphosate herbicide using dilutions and cut-spacings specified on the herbicide label (anytime except March and April). The EZ-Ject tree injector assists in reaching through entanglements to treat, and the glyphosate shells have been found effective in winter.
* Nontarget plants may be killed or injured by root uptake.