Exotic Vines

Chinese yam (Dioscorea oppositifolia)
Chinese yam is also known as cinnamon vine. This plant is composed of herbaceous or slightly woody vines with fleshy or woody roots. Vines twine from left to right and may reach 13 feet in length. Leaves are alternately arranged along the stems (lower leaves may be opposite). Each leaf is oval, with a long tapering point, concave sides and a heart-shaped base. New leaves may have a bronze tint. Green-yellow flowers are produced from June through August. The fruit is a membranous, three-angled capsule. Chinese yam is often confused with wild yam, however the vines of wild yam twine upwards from the right to the left, while those of Chinese yam twine from the left to the right. Chinese yam is a native of Asia that has spread from cultivation in some areas of southern Illinois.

English ivy (Hedera helix)
English ivy, a native of Eurasia, is a climbing woody vine with alternate, dark green, waxy leaves. It was introduced into the United States in colonial times. In contrast to many other woody vines, this plant blooms in the fall, producing purple fruits, that are eaten and dispersed by birds. It is adapted to shade and readily invades forests where it forms dense stands that exclude native species. It produces a large number of adventitious roots which enables it to climb trees. The waxy layer on the leaves makes it especially resistant to herbicides.

Japanese honeysuckle (Lonicera japonica)
Japanese honeysuckle is a woody vine native to Asia. It is characterized by simple, evergreen, opposite leaves and fragrant, white, tubular flowers that turn yellow as they age. Blooming occurs in May and June in Illinois, and the small, black fruits that are produced in late summer and fall are dispersed by birds. Although it is most common in openings, fence rows and roadsides, this plant can invade woodlands where it forms thick stands that smother out native vegetation. Although it is most abundant in the southern part of the state, it is becoming more common further north. Its sale is prohibited in Illinois.

kudzu-vine (Pueraria lobata)
Kudzu is a woody vine known for its very rapid growth. It is a member of the bean family and has large trifoliate leaves. The purple flowers are produced from August through September. A native of China and Japan, it was introduced into the United States at the Philadelphia Centennial Exposition in 1876. During the 1930s rootstocks of kudzu were extensively planted on badly eroded lands in the southern states, and it now covers an estimated seven million acres of land, most in the southeastern United States. Kudzu starts new colonies by fragmentation of the stems and roots. It is becoming established statewide in Illinois. This species is designated as a noxious weed in Illinois.

Oriental bittersweet (Celastrus orbiculatus)
Oriental bittersweet is a deciduous, woody vine that can grow 50 or more feet into the canopy of forest trees. Its vines, which may grow five inches or more in diameter, produce alternate, oval leaves which turn yellow in the fall. The small, yellow-green flowers produced from May through June are inconspicuous. Capsules open in the fall to reveal the bright red flesh which covers the seeds. Fruits are produced along the stem in contrast to the native bittersweet that produces fruit only at the tips of the stems. The fruits are eaten and dispersed by birds, and people also disperse this plant by using it in dried flower arrangements and discarding the seeds. The twining growth habit of oriental bittersweet constricts trees, its dense foliage reduces sunlight, and the extensive growth in tree canopies makes trees top heavy and more susceptible to wind damage. Oriental bittersweet grows in scattered locations throughout the state.

wintercreeper or climbing Euonymus (Euonymus fortunei)
Wintercreeper is a woody vine native to Asia. It has simple, leathery, oppositely arranged leaves. The small, yellow-green flowers are borne in clusters during June. The fruit is a smooth capsule that splits open in the fall to reveal a red covering over the black seeds. The seeds are dispersed by birds in their wastes throughout woodlands. Wintercreeper vines grow on the ground, covering native wildflowers and threatening their survival. The prolific formation of adventitious roots allows this vine to climb and interfere with the growth of trees.

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