Isotrema macrophyllum

About

Aristolochia macrophylla, Dutchman's pipe or pipevine, is a perennial vine native to the eastern United States. A. macrophylla belongs to the plant family Aristolochiaceae and is found primarily along the Cumberland Mountains and Blue Ridge Mountains in the eastern portion of the United States, as well as Ontario, Canada. This species of plant has received considerable attention in the past few decades for the discovery of a potent compound called aristolochic acid, which has been the focus of debate due its harmful side effects.

Summary from Wikipedia