European swallow-wort

Vincetoxicum rossicum is a flowering plant of the milkweed family. 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. There has historically been much confusion about the genus it belongs to, with authors placing it within Vincetoxicum and others...