Invasive Species | Terrestrial Plants
Dog-Strangling Vine
Photo: Rob Routledge, Sault College, Bugwood.org
Dog-strangling Vine
Also known as Black and Pale Swallow-wort
(Cynanchum rossicum & Cynanchum louiseae)
French common name: Dompte-venin de Russie/dompte-venin noir et pâle
A member of the milkweed family, Dog-strangling Vine (DSV) spreads along the ground and twines around other plants and trees, forming dense patches that outcompete native plants, interfere with infrastructure like utility corridors, and hinder forestry and agricultural operations. DSV also impacts endangered Monarch Butterfly populations as the butterflies will mistakenly lay their eggs on this plant instead of native milkweed, but once hatched the caterpillars cannot feed on DSV and die.
Characteristics
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Life cycle: An aggressive perennial vine that forms a well established root system; reproduces through root fragments and seeds that are easily spread by wind.
Size/structure: grows up to 2 meters tall; climbs other plants or tangles around itself.
Leaves: opposite, smooth, and oval-shaped with a pointed tip; 7–12 cm long.
Flowers: clusters of small, star-shaped flowers, with 5 pink to dark-purple petals; blooms late May to mid-July.
Seed pods: Bean-shaped pods; yellowish-green and 4–7 cm long; form midsummer and contain seeds attached to feathery white tufts that disperse from opened pods.
Key ID Features
Rob Routledge, Sault College, Bugwood.org
Tiny pink or purple star-shaped flowers
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Intertwining or “strangling” other plants
Chris Evans, University of Illinois, Bugwood.org
Bean-shaped seed pods from mid- to late summer
Common Look-a-Likes
Ohio State Weed Lab , The Ohio State University, Bugwood.org
Swamp Milkweed (Asclepias incarnata)
Round clusters of showy pink flowers
>1.5m tall
Native host for Monarch Butterflies
Nancy Loewenstein, Auburn University, Bugwood.org
Oriental Bittersweet (Celastrus orbiculatus):
Climbing vine, up to 18m tall
Rounded and slightly toothed leaves
Bright red fruit with yellow skin that remains on vine in winter
Highly invasive
Mary Ellen (Mel) Harte, Bugwood.org
Dogbanes (Apocynum ssp):
Light green to red stem that branches at the top
Small white to pink bell-shaped flowers
How It’s Spread
This plant was introduced as a garden species and has been moved into new areas through dumping of garden clippings or movement of garden materials. Learn more about invasive plant species and how you can help to prevent the spread of invasive species when gardening on our Plant Wise program page.