American Wild Yam plant, Dioscorea quaternata. is also known as Four-Leaf Yam and Medicinal Wild Yam. The tea, decoction or tincture of the root eases all types of pain of the uterus. Acts as an anti-spasmodic to smooth muscle. Dioscorea quaternata is medicinally interchangeable with Dioscorea villosa. American Wild Yam plant is native to the hardwood forests of eastern America and prefers moist, well drained soil in dappled light or partial shade. An herbaceous perennial vine, growing to to4m in length. Small yellowish green flowers in racemes are produced in summer.