Skip to main content
Invasive Species: Round Leaf Bittersweet

Invasive Species: Round Leaf Bittersweet

What is round leaf bittersweet?

  • (Celastrus orbiculatus)
    Other common names: Asiatic bittersweet, Oriental bittersweet

    *Established in Michigan*

    Round leaf bittersweet is a woody, twining vine commonly found in woodland edges and occasionally used in autumn decorations. It spreads both by seeds and tip-rooting, forming dense thickets in forest openings, disturbed areas and dunes, crowding out important native vegetation and damaging trees. It also disrupts the food web by reducing food for herbivores and insects and outcompetes native American bittersweet.

     

Identify

  • What to look for

    • Woody, spiraling vine up to 4 inches thick and 60 feet long and lacks tendrils or air roots. Stems are relatively smooth and gray to brown.
    • Leaves are glossy, round to oval with small, rounded teeth. Leaves are often fatter toward the tip side, ending with a small point. Leaf stems are staggered along the vine.
    • Fruits are borne in clusters all along the stem. Individual capsules are round and yellow in fall, splitting into three parts to reveal a dark orange, fleshy aril.
     

Round leaf bittersweet photos

The following images can help identify round leaf bittersweet. Click on each photo for descriptions.

Report

  • To report suspected round leaf bittersweet: 

    Note the location of the suspected round leaf bittersweet and be sure to include at least one photo of the plant to help with verification.

Species information

  • Habitat

    Clearings, woodland edges, roadsides, old fields, grasslands, hedgerows and in urban areas; usually not in wet areas.

    Range

    Native Range: Round leaf bittersweet is native to Japan, Korea and eastern China.

    U.S. Distribution: Found escaped from cultivation throughout the eastern United States. View the EDDMapS distribution map for round leaf bittersweet.

    Michigan Distribution: First collected outside of cultivation in 1976 but likely established much earlier, this vine is found in disturbed habitats throughout Michigan. View the MISIN distribution map of round leaf bittersweet observations.

    Local concern

    Round leaf bittersweet outcompetes native plants and depletes the food sources for insects, deer and other wildlife. It can also damage and even girdle trees and outcompete American bittersweet, a native vine.

    How it spreads

    Originally introduced as a habitat planting, round leaf bittersweet spreads mainly by seeds, both nearby and long distance when carried by birds.

     

Additional information