dog-strangling vine, European swallowwort Vincetoxicumrossicum (Kleopov) Barbarich
Appearance
Vincetoxicum rossicum is an herbaceous, twining, long-lived perennial vine. The vines can reach 5 ft. (1.5 m) in length.
Foliage
Leaves are opposite, dark green, oval, shiny, 3-4 in. (7.6-10.2 cm) long and 2-3 in. (5.1-7.6 cm) wide. They are attached to the vine by a petiole about 0.4 in. (1 cm).
Flowers
Flowering occurs in June to September, when dark pink to deep red, 5-petaled, star-shaped flowers appear in clusters. Flowers are approximately 0.25 in. (0.6 cm) across and are covered with white hairs.
Fruit
The fruits are similar to milkweed pods. They are slender, 2-3 in. (5.1-7.6 cm) long and split to reveal small seeds with tufts of white hairs. The hairs allow the seeds to be readily dispersed by the wind.
Ecological Threat
Vincetoxicum rossicum invades upland areas and tolerates a wide range of light and moisture conditions. It can grow rapidly over native vegetation to the point of dominating the understory of a woodland. Wind-dispersed seeds allow it to disperse over long distances. When it is cut, this plant resprouts vigorously, making control difficult. It is native to Europe and was likely introduced into the United States for ornamental purposes.