Radix Cynanchi
Atrati
Source
The root and rhizome of Cynanchum atratum Bunge or C versicolor 
Bunge,
fimily Asclepiadaceae.
Characteristics
Crude drugs somewhat horse's tail-shaped, 10-15 cm long. Rhizome stout.
tubercular, transversely growing, with circular stem traces at the upper
part and numerous slender roots growing in cluster at the lower. Root
0. l~O.2 cm in diameter, grey-yellow and fragile. Prepared as segments.
Bitter and salty in taste, cold in nature, and attributiye to stomach
and liver channels.
Indication
1. Lower asthenic fever: For seasonal febrile disease involving. yinfen
with pmlonged fever or high fever at night subsiding in the morning, 
infantile
summer fever, postpartum fever, etc., usually used together with Cbrtex
Lycil Radicis, Herba Artemisiae AflflNae, etc.
2. Let out the evil factors from the body surface: For common cold with
prolonged fever, especially those with yin deficiency.
3. Promote diuresis and relieve stranguria: For stranguria of heat type,
and stranguria complicated by hematuria.
Pharmacological
Action
An active component contained in its root, cynanchol, can lower fever
and promote diuresis.
Administration Decoction: 3-9g.