Also called swallowwort and dog-strangling vine.  Formerly called Vincetoxicum rossicum.

Native to southern 🇪🇺 Europe.  Invasive > learn+quiz Invasive > Global Invasive > in USA+Canada Invasive > report it! Invasive > in USA Invasive > in USFS (.pdf) Invasive > in Michigan (.pdf page 50)

For kids!  This plant described in invasive species placemat (.pdf) series

This plant is particularly harmful in areas with the monarch butterfly Danaus plexippus, as this plant is similar enough to milkweed (genus Asclepias and related genera) to attract Monarch adults to lay their eggs on it, but different enough that their young (monarch caterpillars) cannot feed on it, thus eliminating these monarchs from the ecosystem. 

Learn more about pale swallow-wort Cynanchum rossicum

Best Control Practices BCP (Michigan) (.pdf) Best Control Practices BCP (Ontario) (.pdf) and its Technical Bulletin (.pdf) Fact sheet (Ontario) 🇫🇷 en français (.pdf) Biological Control in Eastern USA (.pdf page 217)
Discover Life Encyclopedia of Life Google Google images Michigan Flora USDA PLANTS db USFS Wikipedia