Dioscorea villosa (wild yam)

The wild yam vine  grows best in full sun to produce flowers, or can survive in part shade without producing flowers.  The yellow-green flowers will bloom in the late spring, and will vary  in appearance depending on whether a male or female plant.  (It will be unknown for these plants until they have matured, so you may wish to purchase a few to increase odds of cross-pollination.)  Wild yam prefers medium moisture in soils that are well-drained, moist, or occasionally dry.  This is a herbaceous vine, so it dies back to the ground in the winter and emerges in the spring.  Grow plants on a trellis to help provide a seasonal visual screen.

Photo by Doug McGrady, Flickr

BONAP Native Range Map (bright green indicates county native, dark green indicates state native)