Acorus calamus.  Sweet flag, Calamus, Sweet flag root   Family: Araceae    
Acorus calamus var americanus- a diploid American variety
Acorus calamus var vulgaris- A European triploid
Acorus calamus var augustatus and Acorus calamus var versus- subtropical tetraploids.
The rhizome has been used candied and in the form of an infusion since ancient times.
PART USED: Rhizome
TASTE: Aromatic, pungent ODOR: Sweet and aromatic.
ACTIONS
GROUP: The Gastro-Intestinal Tract- Stomachic.[1,2]
1 . Antispasmodic.[1,2,3]
2 . Bitter tonic.[2] Aromatic.[3]
3 . Carminative.[1,2,3]
4 . Diaphoretic.[1,2]
INDICATIONS
1. Stomach disorders including anorexia. Acute and chronic dyspepsia.[1,3] Gastric ulcer.[1] Flatulent colic.[1,2] Gastric hyperacidity.[2] Gastritis.[1] Intestinal colic.[1,3] Flatulence.[3]
2. Nutritive for babies and invalids.[2]
3. Anorexia.[1]
4. Malaria.[2] Ague-[3] a fever (as malaria) marked by paroxysms of chills, fever, and sweating that recur at regular intervals.
SPECIFIC INDICATION: Flatulent colic.[1]
COMBINATIONS
PREPARATIONS:   3 times/day
The rhizome is collected in autumn, trimmed, and sometimes scraped or peeled. It is indigenous to Eastern Europe and Central Asia, where it grows as a reed like plant to over one metre in height.
Dried rhizome  1-3 g.[1,2] Powdered root 1-4 g.[3]
Infusion  20-60 ml.
Fluid extract 1: 1 in 60% alcohol, 1-3 ml.[1,2] 1-4 ml.[3]
Tincture 1:5 in 60% alcohol  2-4 ml.[1,2]
HABITAT: River banks and marshy places
DESCRIPTION: The rhizome is pale fawn coloured, longitudinally wrinkled, with numerous oblique transverse leaf scars above, particularly near the stem, and small circular root scars underneath. Fracture short, showing a whitish, porous interior with scattered vascular bundles visible when wetted.
References
Inner Path can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally. Acorus calamus
Constituents.
Bitter volatile oil 1.5-3.5% containing b-[3]asarone to 80%,[1,2] up to 96% in the varieties- vulgaris, angustatus and versus.[3] In Acorus calamus var americanus, b-aserone and other phenylpropanoids are absent, and the main constituents are the sesquiterpenes shyobunone, 6-epishyobunone, 2,6-diephishyobunone; together with up to 35% isacorone, 25% acorone and acorenone and small amounts of calamendiols.[3] Other constituents of the oil are sesquiterpene hydrocarbons such as l-cacala-1,4,9-triene, guaiane sesquiterpene ketones,[4] acoragermacrone,[5] acolamone, isacolamone, pinene, aculene, methyleugenol, methylisoeugenol, camphor, asoraldehyde and acoric acid.[6]
Eugenol and asamyl alcohol.[1]
Bitter principle Acorin.[1,2]  Tannin.[1]  Starch.[1]
References [1] British Herbal Pharmacopoeia 1983 Published by the British Herbal Medicine Association ISBN 0 903032 07 4.
[2] Herbal Materia Medica Course Notes For Diploma of Naturopathy and Diploma of Herbalism Students by Lydia Mottram.
[3] Keller, K. et al. (1985) Planta Med. 51 (1), 6
[4] Rohr, M, and Naegeli, P. (1979) Phytochem. 18 (2), 279
[5] Iguchi, M. et al. (1973) Tet. Lett. 29, 2759
[6] Encyclopedia of common Natural Ingredients used in Food Drugs and Cosmetics, Albert Y. Leung. Pub. John Wiley & Sons Inc. (1980) NY
Images
1. en.wikipedia.org by J.F. Gaffard, Autoreille, France CC BY-SA 3.0
2. jadibutinepal.com
3. godasagardener.com
Research.

Pharmacological studies in China have shown that extracts of Calamus have anti-arrhythmic, hypotensive, vasodilatory, antitussive, antibacterial and expectorant activity.[1]
Toxicity studies there showed that the oil was of low toxicity in animals and adverse reactions in patients rare.[1]
It has been shown that b-asarone is carinogenic in animals; however recent studes have demonstrated that Acorus calamus var americanus, which does not contain b-asarone, is in fact superior in spasmolytic activity to the other types.[2] Therefore, although abolute safety has not been proven yet, it would be preferable to use this variety for internal use.[3]
Preparations containing b-asarone are banned from sale in the USA.[3]
References
[1] Pharmacology and Aplications of Chinese Materia Medica Vol 1, Ed. H. chan and P. But, Pub. World Scientific (1986) Singapore
[2] Keller, K. et al. (1985) Planta Med. 51 (1), 6
[3] Potter's New Cyclopaedia of Botanical Drugs and Preparations  R.C. Wren Revised by Elizabeth M. Williamson and Fred J Evans. First published in Great Britain in 1988 and reprinted in 1989 and 1994 by the C. W. Daniel Company Limited. 1 Church Path, Saffron Walden Essex. Published 1988 Printed and bound by Biddles, Guildford ISBN 085207 1973.