Round Leaf Bittersweet
Celastrus orbiculatus
Washington State Classification
Class A — Eradication Required Statewide
Round leaf bittersweet grows very fast, both vertically choking trees, and horizontally infesting through a forest.
Quick Reference
Identification
Growth Habit
Deciduous, woody vine, which can grow to over 100 feet up vegetation and the landscape.
Leaves
Generally round, with shallow to deep serration. Leaves grow alternately up stems. Leaves are generally light to lime green in the summer, and age to a bright yellow in the autumn.
Flowers
Small (less than 1cm wide), inconspicuous white to pale green or yellow, with 5 petals.
Fruit & Seeds
Berries start green and mature to a very obvious red to orange berries grow all along the stems with leaves. There is often a leathery yellow outer wall that peels back and can remain on the berries. The berries remain on plants through the winter, providing food to birds.
Impact
Round leaf bittersweet grows very fast, both vertically choking trees, and horizontally infesting through a forest.
Ecology & Spread
Habitat
Deep to partial shade in forested and moist areas. Click here to see an informal map of known roundleaf bittersweet locations in Washington as of January 2025.
Spread Mechanisms
Reproduction
Vegetatively through root suckering, horizonal vegetative spread, breaking off and resprouting of stems. Also by seed, which are very attractive to birds, which spread to remote forested areas.
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