Herbs that Cool the Blood

What is the taste and temperature of Sheng Di Huang (rehmanniae radix)?

Sheng Di Huang is cold and bitter because it clears heat and cools the blood. It is sweet because it tonifies yin and moistens dryness.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 118 [Q382]