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GREATjU <br />RIVERlRIPW <br />GREENING <br />Woody Species <br />Oriental Bittersweet (Celastrus orbiculatus) <br />Description <br />Oriental bittersweet is a recent threat to Minnesota native habitats, having escaped from cultivation. It <br />is a robust vine that climbs by twining around a support. The vine can grow up to 60 feet or more. The <br />vines have been reported to be so vigorous that they can overwhelm and kill a tree either by blocking <br />light to the canopy or by causing it to be more susceptible to windthrow and breakage when loaded with <br />ice or snow. The vines may also girdle trees as they twine around the trunk. Stems are gray -brown with <br />raised lenticels and may grow as big as 4 inches around. Vegetatively, it is very similar to and difficult to <br />distinguish from the native American bittersweet. The leaves of both species are alternate, simple, and <br />range from oblong to nearly round in shape with rounded teeth on the margins. <br />Male and female flowers occur on separate plants, so only the female plants will have the showy fruit <br />for identification. American bittersweet flowers and fruits occur on the terminal ends of the stems, <br />while those of oriental bittersweet occur in the leaf axils along the stem. The fruits of American <br />bittersweet are red with an orange capsule, while those of oriental bittersweet are red with a yellow <br />capsule. The two species are known to hybridize, and the hybrids should be controlled as well. Oriental <br />bittersweet, like its native counterpart, spreads by suckering as well as by seed. <br />Mechanical <br />Small populations can be controlled by digging in locations where that treatment is feasible. Mowing is <br />not recommended and may stimulate additional suckering from the root system. <br />Chemical <br />Cutting and treating the stumps will likely be the most effective control method. Cut stems may be <br />treated with glyphosate or triclopyr. Cut stump treatment can occur from mid -summer through winter. <br />In areas with extensive establishment of seedlings and young plants, a foliar herbicide treatment can be <br />used for control. <br />Long-term Management <br />Oriental bittersweet is a prohibited noxious weed. All parts of it must be destroyed. Do not transport, <br />propagate, or otherwise distribute any plant parts, including the ornamental fruits. <br />Oriental Bittersweet <br />April May June <br />July <br />Aug <br />Sept <br />Oct <br />Nov <br />Dec - <br />Mar <br />Foliar Herbicide <br />Cut Stem Herbicide <br />Mow <br />Flowering <br />