What it is:
This herb is thestem tuber of Gas-trodia elata Bl. (family Orchidaceae) which is principally produced in Sichuan,Yunnan and Guizhou provinces. It is dugin winter, washed clean after removal of the aboveground stem and hypha, thenskinned, thoroughly boiled, dried in sunlight or baked dry,and sliced for use.

Property:
Sweet in flavour, neutral in property,acting on the liverchannel.

Effects:
Checkingendogenous wind to relieve convulsion, calming the liver and suppressing hyperactivity of theliver-yang, and removing obstructionin the collaterals to relieve pain.

Used for:
1. Up- stirring of endogenous wind due to liver disordersshown as epilepsy induced by fright and convulsion. In the treatment of infantile convulsiondue to high fever, it can be given to-gether with uncaria stem, antelope's horn and scorpion, as in Uncaria Decoction(Gouteng Tang) ; to treat chronic infan-tile convulsion due to deficiency of thespleen, it can be used along with ginseng, white atra-ctylodes rhizomeand batryticated silkworm, as in Decoction for Invigo-rating the Spleen (Xingpi San);to treattetanus, it can be used together with arisaema tuber, ledebouriella root and giant typhonium tuber, as in Powder with Marvellous Effect (Yuzhen San).

2. Headache and light-headedness. Ifthese symptoms are caused by hyperacti-vity of the liver-yang, it can be usedwith uncaria stem, scutellaria root andachyranthes root, as in Decoction of Gastrodia and Uncaria(Tianma Gouteng Yin);if the symptoms are caused by upward movement of wind-phlegm., it can be given together withpinellia tuber, WhiteAtractylodes rhizomeand poria, as in Decoction of Pinellia,White Atractylodes and Gastrodia (BanxiaBaizhu Tianma Tang);if they are caused by deficiency of bloodand yin, chinese angelica root, whitepeony root and prepared rehmannia root can be added; for chronic headacheand migraine with frequent recurrences,it is often used with chuanxiong rhizome, as in Gastro-dia Bolus(TianMa Wan).

3. Rheumatic arthralgia, numbnessof the limbs or tetra-plegia. It is often used with large-leafgentian root,pube-scent angelica root,achyranthes root andmulberry mistletoe stem.

Dosage and admi-nistration: 3-10g, decocted in water for an oral dose, orground into powder for swallows, 1-1.5geach swallow.