INVASIVE PLANT SPECIES FACT SHEET Oriental Bittersweet Celastrus orbiculatus

Description: Problem: Origin:

Oriental bittersweet Oriental bittersweet can Oriental bittersweet’s is a rapidly spreading overrun natural vegetation, habitat on its native deciduous, twining vine forming nearly pure continent of Asia is said with alternate round, stands in forests. It to be lowland slopes or glossy leaves. The outer can strangle shrubs and thickets at altitudes from surface of its roots are small trees, and weaken 100 to 1,400 meters. The characteristically bright mature trees by girdling vine is widely distributed orange. The branches the trunk and weighting in northern and central are round, glabrous, light the crown making the Japan and Korea. In to dark brown, usually tree more susceptible to China it is found primarily with noticeable lenticels. damage. There is also a in provinces north of the Small greenish flowers concern that this spe- Yangtze River. occur in clusters in the cies is hybridizing with leaf axils. At maturity, American bittersweet and globular, green to yellow threatening to genetically fruits split open to reveal eliminate the native spe- three red-orange, fleshy cies. arils that contain the seeds. This species may be distinguished from the native Celastrus scandens by the location of its fruit. C. orbiculatus has small clusters in Picture By: The Nature Conservancy. Pictures By (From top to bottom): the leaf axils while C. L. J. Mehrhoff, J. Randall and J. H. Miller @ www.invasive.org. scandens has clusters IPSAWG Ranking: only at its branch tips.

HIGH HIGH HIGH Invasive Plants Distribution: are a Threat to:

Oriental bittersweet was Ecological Potential for Difficulty of • Forests and brought to the United Impact Expansion Control wetlands States for cultivation during the middle of the IPSAWG Recommendation: • Native plants nineteenth century. It is now naturalized in 21 •Do not buy, sell or plant Oriental bittersweet in Indiana. • Perennial gardens of the 33 states where it was introduced, a region •Help by eradicating Oriental bittersweet on your property. • extending from Maine Wildlife south to Georgia and west to Iowa. In Indiana, This ranking illustrates the results of an assessment conducted • Lakes and rivers by the Invasive Plant Species Assessment Working Group it is locally abundant (IPSAWG), which is made up of many organizations and agencies in the southern third of concerned about invasive plant species. IPSAWG’s goal is to assess • Human Health the state and in several which plant species may threaten natural areas in Indiana and counties in northwest develop recommendations to reduce their use in the state. • Farmland Indiana. For more information about IPSAWG and the assessment tool used to rank invasive species, visit their website: Date Updated: 10/06 www.invasivespecies.IN.gov Control Methods: ALTERNATIVES to Oriental Bittersweet: Vines can be pulled out When using glyphosate necessary to control new by the root and removed or triclopyr, cut the stem 5 seedlings. Always read from the site. If fruits are cm. above ground level. and follow pesticide present, they should be Immediately apply a 25% label directions. bagged and disposed solution of glyphosate of. Certain systemic or triclopyr to the cross- herbicides, such as section of the stem. This glyphosate or triclopyr, that procedure is effective are taken into the roots and at temperatures as low Virgin’s bower kill the entire plant, have as 40°F. A subsequent (Clematis virginiana) been used successfully. foliar application may be

Trumpet Honeysuckle (Lonicera sempervirens) Oriental bittersweet smothering native plants. (Picture by: The Nature Conservancy. Eight Easy Ways to Combat Invasive Plants

You can help stop the spread of invasive plants by following these 8 easy guidelines: 1. Ask for only non- for invasive species, and and natural areas to assist invasive species when you remove invasives before ongoing efforts to diminish Woolly Dutchman’s Pipe acquire plants. Request that they become a problem. If the threat of invasive (Aristolochia tomentosa) nurseries and garden plants can’t be removed, plants. centers sell only non- at least prevent them from 7. Help educate your Pictures By (Top to Bottom): D. Lieb- going to seed. man, J. Lepore and S. Baskauf. invasive plants. community through 2. Seek information on 4. Clean your boots before personal contacts and in Other Alternatives: invasive plants. Sources and after visiting a natural such settings as garden area to prevent the spread Virgina Creeper include botanical gardens, clubs and civic groups. of invasive plant seeds. (Parthenocissus horticulturists, 8. Support public policies conservationists, and 5. Don’t release aquarium and programs to control quinquefolia) plants into the wild. Crossvine government agencies. invasive plants. 3. Scout your property 6. Volunteer at local parks (Bignonia capreolata) For More Information: Not Recommended: On this assessment and IPSAWG: American bittersweet IPSAWG (Celastrus scandens) www.invasivespecies.IN.gov While American bittersweet On identification and control techniques: is native and non- The Nature Conservancy’s Wildland Weeds invasive, unfortunately, www.tncweeds.ucdavis.edu nurseries often mislabel On native plant alternatives and sources: Oriental bittersweet as Indiana Native Plant and Wildflower Society American bittersweet. It www.inpaws.org is very difficult to find true This grant project made possible with United States Forest Service funds American bittersweet for sale. administered by the IDNR, Division of Forestry.