Source:
The aerial parts of Equisetum hiemale L, E. arvense L and E. ramosissimum
Desf., family Equisetaceae.
Characterisfics
Stem long-tubular, branching or not branching, yellow~reen; with many
longitudinal ribs on the outer surface; nodes noticeable, beafing 
cylindrical
scaly leaves which are marked by black annular rings; and apexes dentate.
Very coarse in texture. Sweet and slightly bitter in taste, mild in nature,
and attributive to lung, liver and gallbladder channels.
Indication
1. Expel wind and heat, improve visual acuity and remove nebula: For win~heat
syndrome with swelling and pain of the eyes, ик_conjunctivitis, photophobia,
headache, mild chilliness, fever, anhidrosis and nebula formation.
2. Lower blood pressure: For hypertension, in addition, may relieve the
symptom of silicosis; intramuscular injection is effective for psoriasis;
extemal application of decoction containing 30g of the drug and 30g of
Rhizoma
Cyperi for common wart.
Pharmacological Action
1. Interperitoneal or duodenal administration of its alcoholic extract
exerts a sustained hypotensive effect on anesthetized cats.
2. Sedative.
3. Elevating the plasma level of cAMP and cGMP in mice.
Administration Decoction: 3-9g; and 50-i 50g for hypertension.