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Invasive Species Sheet - Asiatic Bittersweet

Invasive Species Identification Sheet

Asiatic Bittersweet (Celastrus orbiculatus Thunb.)

Alternate Common Names: Asian, Oriental, or Round-leaved Bittersweet
- deciduous, woody vine; climbs (or trails on the ground) by twining stems rather than tendrils
- leaves alternate, 2"-5" long, roundish to long-tipped in outline; margins finely toothed
- vigorous growth; may cover tree tops at forest edges; yellow leaves remain into late autumn
- showy fruit has bright red color in late autumn and winter on female plants
- outer surface of roots is bright orange
- buds set at right angles to stems (easily seen in winter)

Asiatic Bittersweet is recognized at a distance by its glossy leaves, excessive climbing over other plants, and showy fruits. Even as a seedling, its tendency to grow in a twining form is evident. Asiatic Bittersweet vines may grow to 60' long and 5" in diameter. As the fruit ripens, it changes from a green to a yellow capsule. When the fruits are ripe in the fall, they show red and yellow color. The yellow is on the inside of the ovary wall which has split open to reveal the bright red, fleshy seed coatings. In winter, the ovary walls may have fallen off leaving what looks like a bright red, 1/4" berry.

Asiatic Bittersweet is distinguished from the native American Bittersweet (Celastrus scandens L.) by the fruits. In Asiatic Bittersweet, the fruits grow in clusters of 2-3 (up to 7 fruits) from the point where the leaves are attached. Long stretches of stem may have many clusters along their length. In American Bittersweet, fruits are numerous, orange-coated when ripe and are located only at the tips of branchlets, not along the length of the stems. Beware mislabeled nursery stock.

Asiatic Bittersweet is most problematic in sunny openings or at edges where forests or hedgerows meet roads, fields, meadows, salt marshes, or other open areas. Asiatic Bittersweet may retard forest regeneration and smother native vegetation in meadows, thickets and young forests. There is concern for possible altering of the native bittersweet through hybridization.