Canada

Dog-strangling vine

Vincetoxicum rossicum

Dog-strangling vine prefers open sunny areas, but can grow well in light shade. It grows aggressively up to two metres high by wrapping itself around trees and other plants, or trailing along the ground. Dense patches of the vine can "strangle" plants and small trees.
The plant can produce up to 28,000 seeds per square metre. The seeds are easily spread by the wind, and new plants can grow from root fragments, making it difficult to destroy. The vine has invaded ravines, hillsides, fence lines, stream banks, roadsides and utility corridors. Dog-strangling vine is also found in prairies, alvars (limestone plains), plantations of pine trees and natural forests.
Impacts of Dog-Strangling Vine:
Dog-strangling vine forms dense stands that overwhelm and crowd out native plants and young trees, preventing forest regeneration.
Colonies form mats of interwoven vines that are difficult to walk through and interfere with forest management and recreational activities.
Leaves and roots may be toxic to livestock. Deer and other browsing animals also avoid dog-strangling vine, which can increase grazing pressure on more palatable native plants.
The vine threatens the monarch butterfly, a species at risk in Ontario. The butterflies lay their eggs on the plant, but the larvae are unable to complete their life cycle and do not survive.
How to Identify Dog-Strangling Vine
Grows one to two metres high by twining onto plants, trees or other structures.
Leaves are oval with a pointed tip, seven to 12 centimetres long, and grow on opposite sides of the stem.
Pink to dark purple star-shaped flowers have five petals about five to nine millimetres long.
The plant produces bean-shaped seed pods four to seven centimetres long that open to release feathery white seeds in late summer.