Cynanchum louiseae, a species in the milkweed family, is also known as Black swallow-wort, Louise's swallow-wort., or Black dog-strangling vine, Cynanchum louiseae is a species of plant that is native to Europe and is found primarily in Italy, France, Portugal, and Spain. It is an invasive plant species in the northeastern United States, parts of the Midwest, southeastern Canada, and California.
Read more about Cynanchum Louiseae: Description, Invasiveness, Management