Synonyms: Cynanchum rossicum
Common Names: Dog-strangling vine, European swallowwort
Description: Grows rapidly over native vegetation; wind-dispersed seed travels long distances.
Habit: Herbaceous perennials, both range from 0.6-1.8 m (2-6 ft) tall.
Leaves: Simple, opposite, narrow, oblong to ovate with a pointed tip, dark green leaves with a smooth, waxy coating; emits a pungent herbal smell when crushed.
Stems: Twining; may climb or creep around adjacent plants.
Flowers: Small, five-petaled; clustered in leaf axils; slight rotting odor; pale to dark maroon, purple or pink; glabrous; peduncles 2-5 mm; blooms June through August.
Fruit and seeds: Seed pod, resemble those of milkweed, pods split open in mid-summer to release wind-borne seeds.
Habitat: Native to southern Europe. Found in hardwood forests, shaded woods, open prairies, fields, savannas, roadsides; can tolerate a range of light and soil conditions.
Reproduction: By seed, vegetatively by rhizomes and shoots from root crown of parent plant.
Similar species: Native dogbanes (
Apocynum spp.) have similar seedpods but are not vines.
Monitoring and rapid response: Monitor disturbed sites and also edges and paths in undisturbed sites; populations most visible in late summer when the leaves turn golden and seedpods appear. Hand-pulling difficult as roots are fragile, digging preferred, remove roots from site. Foliar herbicide treatment provides effective control; cut-stem herbicide application provides slightly less effective control and is labor intensive. Prescribed fire is not effective when used alone and may improve conditions for increased germination; fire may be useful following herbicide application to control seedlings with less developed root systems. Remove and burn seedpods; multi-year monitoring and follow-up required. Please report sightings with GPS positions to Dr. DiTommaso at: ad97@cornell.edu.
Credits: The
Michigan Natural Features Inventory (MNFI) has partnered with MISIN to provide the information in this fact sheet. Species images and/or information were used with permission from "
A Field Identification Guide to Invasive Plants in Michigan's Natural Communities" and "
A Field Guide to Invasive Plants of Aquatic and Wetland Habitats for Michigan.