Pest Photo

Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Black swallow-wort

Cynanchum louiseae

Black swallow-wort (Cynanchum louiseae) is an invasive plant. It is a native of Europe and was first detected in Massachussetts in 1864.

It is an invasive plant species in the northeastern United States, parts of the Midwest, southeastern Canada, and California. In the United States and Canada, Cynanchum louiseae is a threat to native species because it crowds out native species.