Medicinally it mainly refers to the fresh or dried root of Rehmannia glutinosa Libosch. which is one of medicinal 

plants in the family Scrophulariaceae.  Rehmannia root is a very commonly used herb in traditional Chinese medicine. 

And it is also cultivated in most parts of China. It is generally harvested in autumn. The following steps are to remove 

the residual part of stem, fibrous root, and soil. It is normally used fresh or dried.  Rehmannia has astringent properties 

that make it useful in stopping bleeding. It helps to protect and support the liver and adrenal glands and is often found 

in energy tonic formulas to used to combat chronic fatigue. 

-You can drink the tea hot or cold.

-Avoid exposure to direct sunlight, keep in a cool, dry place.

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