Rehmannia is a traditional Chinese herb. In Chinese, it is called Di Huang. It is also known as Chinese foxglove.
Rehmannia contains the vitamins A, B, C, and D, as well as other compounds, such as catalpol, an iridoid glycoside.
The raw Rehmannia root is called as Sheng Di Huang. In Chinese Medicine, the root can also be cooked in red wine. Then it is known as Shu Di Huang (prepared Rehmannia). In Chinese herbal medicine, prepared Rehmannia is mainly used for enhancing yin.