Oriental bittersweet, Celastrus orbiculatus, infestations overtake and destroy forests and grasslands by girdling and breaking trees and shading and smothering all plants. For the health and biodiversity of our forests and grasslands, it is important to find and eliminate Oriental bittersweet infestations.
Background: Native to Asia, Oriental bittersweet was planted in North America as an ornamental for its attractive fall fruiting branches. Unfortunately, it escaped cultivation and is severely damaging urban and natural forests and grasslands. Wildlife, especially birds, consume the fruit and move seeds to new locations. People collect the fruiting branches to make seasonal decorations resulting in additional seed dispersal. Oriental bittersweet is so destructive that an increasing number of states are regulating it as a noxious weed: Connecticut, Iowa, Massachusetts, Minnesota, New Hampshire, New York, North Carolina, Vermont, and Wisconsin. Oriental bittersweet is considered a high priority invasive plant management issue in many additional states.
Description: Oriental bittersweet vines grow up to 66’ long and have large root systems that send up new shoots. The vines twine around trees and structures. The leaves change in color from green to yellow in the fall. Leaves are alternate and the shape varies from oblong to round. Plants are either male or female and flower in late spring. Fruit only develop on female plants. Fruits are round and change color from green to bright red with a yellow capsule (fruit cover that splits open when mature) in the fall. Flowers and fruit are arranged in clusters where the leaves attach to the vines.
Similar Native Vine: American bittersweet, C. scandens, is a closely related native vine. The species are distinguished by fruit (female plants) and flower placement (male and female plants) on the vines. Flowering and fruiting occur at the leaf axils of Oriental bittersweet plants versus the terminal ends of American bittersweet vines. Fruit capsule color is also a distinguishing factor. Oriental bittersweet has yellow fruit capsules and American has bright orange capsules.
More information can be found at the following website:
Oriental Bittersweet (Celastrus orbiculatus) | Minnesota DNR (state.mn.us)