As the doctrine of signatures might suggest, wild yam is spleen tonic. It is antispasmodic and used to quell nausea, especially during pregnancy. One of its chief constituents is a steroidal saponin that is used in rheumatoid arthritis treatment, but the herb as a whole is demulcent, nourishing, soothing, and tonifying. It makes an excellent supplement for people suffering from deficiency conditions, especially during convalescence or after the age of 65.