European Swallow-wort

Vincetoxicum rossicum is a flowering plant in the family Apocynaceae. It is a perennial herb native to southern Europe and is a highly invasive plant growing in all of the Eastern United States, in the mid west, and southern Ontario and Quebec in Canada. It has several common names including swallowwort, pale swallowwort, and dog-strangling vine; though it does not actually strangle dogs, it can “strangle” native plants and small trees if it is in dense patches. There has historically been much confusion about the genus it belongs to, with authors placing it within Vincetoxicum and others within Cynanchum, but recent molecular and chemical analyses have shown it to belong in the genus Vincetoxicum.