Chinese Clematis
( Clematis orientalis L.)
Native to Asia, this perennial, herbaceous to woody vine has solitary yellow flowers. It blooms late in the growing season on new wood with leaves that are opposite and may be in groups of three. This species prefers a variety of habitats including riverbanks, riparian forests and slopes in hot dry valleys, especially on rocks by rivers and may occur up to 8500 feet in elevation. Chinese clematis, a climbing vine, may cover trees and shrubbery and reducing photosynthesis causing the affected plants to wither.
Chinese clematis has spread extensively in the Clear Creek Valley around Idaho Springs and Georgetown. In El Paso County, this clematis is found primarily west of I-25 to the foothills ranging from the middle of the county south to the southern boundary.
Flower color and bloom dates are the prime distinguishing features of Chinese clematis aiding in the separation of this clematis species from those native to Colorado. Native plants’ blossoms vary in color from blue to brownish-purple, yet Chinese clematis bears yellow flowers. When the native species are at the end of their floral phase for the season, attention to detail is required to separate them from this alien weed.
Chinese clematis is one of the weeds that require management statewide in accordance with the Colorado Noxious Weed Act. The prescribed management techniques are limited the use of herbicides and hand-pulling or digging.