The Medicinal Herb Info site was created to help educate visitors about the often forgotten wisdom of the old ways of treating illnesses. Many of today's drugs and medicines were originally derived from natural ingredients, combinations of plants and other items found in nature.

We are not suggesting that you ignore the help of trained medical professionals, simply that you have additional options available for treating illnesses. Often the most effective treatment involves a responsible blend of both modern and traditional treatments.

We wish you peace and health!

Sweet Flag

Scientific Names

Sweet Flag

  • Acorus calamus L.
  • Acorus Americanus
  • Araceae
  • Arum family

Common Names

  • Calamus
  • Calamus root
  • Grass myrtle
  • Myrtle flag
  • Sea serge
  • Shi-ch’ang-p’u (Chinese name)
  • Sweet cane
  • Sweet grass
  • Sweet myrtle
  • Sweet root
  • Sweet rush
  • Sweet rush root
  • Sweet sedge
  • Vacha (Sanskrit name)

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Parts Usually Used

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Sweet Flag

Description of Plant(s) and Culture

Sweet flag is a strongly aromatic perennial plant; its horizontal, creeping rootstock, which may grow to 5 feet long, produces sword-shaped, striped green and yellow, cattail-like leaves, 3/4 inch wide, and 2-6 feet high, with a vertical midrib, and also a keeled or ridged, thick, fleshy flower stalk which bears a cylindrical spadix covered by minute greenish-yellow flowers. The leaf-like spathe covering the stalk continues past the spadix to the same length as the leaves. The finger-like flowerheads, jutting at an angle about 1/3 of the way up the stem, are usually found on a low percentage of plants in a given population. Flowers May to August.

Sweet flag resembles the cattail or the iris, but it is allied actually to the jack-in-the-pulpit and skunk cabbage. The entire plant has a spicy, lemon fragrance. Sweet flag also resembles the Blue flag (Iris versicolor) but it is not an Iris, however, and may be distinguished from it by its corm and the pungent taste of the leaves.

Other varieties: Variegated sweet flag (Variegatus) of either (A. calamus) 2-3 feet tall or (A. gramineus) the Japanese sweet flag, 6-12 inches tall. The variety ‘Pussilus’ is a dwarf, 5 inch plant that’s good for massing.
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Where Found

Found more or less abundantly throughout the northern hemisphere, in pond edges, marshes, swamps, and the banks of rivers and streams.
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Medicinal Properties

Antispasmodic, aromatic, carminative, decongestant, diaphoretic, emetic, emmenagogue, expectorant, febrifuge, nervine, sedative, stimulant, stomachic, tonic, vulnerary
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Biochemical Information

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Legends, Myths and Stories

It sometimes is credited with aphrodisiac powers; for an extended celebration of its properties, see Walt Whitman’s poem “Calamus”.

Sweet flag root is used in beer makings and flavorings. Roots are used in compositions to flavor gin, cordials, and some vermouths. It must be discreetly used as its aroma overpowers other fragrances. The aroma is likened to ginger and used in India when ginger is not available. It is also chewed to freshen the breath. Made into a tea, or soaked in 75% alcohol (not rubbing alcohol) for a week and then diluted, will make an excellent mouthwash.

One old herbal, Prof. Burnett remarks that sweet flag was consumed in great quantities by perfumers and the makers of hair powder. At the time of his writing, he stated that sweet flag was almost wholly destroyed in the neighborhood by their continual maraudings.

Sweet flag is a widely grown water-plant, used for rush-seating and is a bitter aromatic tonic.

Sliced roots of sweet flag were used in olden times to protect furs and woolens.

On the Chinese New Year, Cantonese cleaned out their homes and placed the sword-shaped leaves near the door. Beneath them was placed a pair of red scrolls bearing an inscription, for example: (The sweet flag, like a sword, destroy’s a thousand evil influences.)

The aroma of sweet flag is the basis for its long history in herb lore. The foliage was widely used as a strewing herb, as the aroma released under the bruising footstep could mask that of unwashed bodies. Strewn on floors in churches and public buildings on occasion of festivities. The lower stem and rhizome can be dried, cut into pieces, and used to scent drawers, closets, and chests. The whole plant has a spicy, lemon fragrance.

Sweet flag has been used as medicine for more than 2000 years. In olden times, sweet flag, or calamus, was recommended by Taoists as having the power to bestow immortality. Dioscorides mentioned that it helps the cough. And in another part of the world, not discovered until some 1400 years later, Native Americans were using sweet flag for colds.
In cooking, the sweet flag or calamus root is sometimes used as a substitute for ginger, cinnamon, or nutmeg.

Commercially, the rhizome has found its way into hair and tooth powders and beverages., including beer, bitters, tonics, liqueurs, and cordials. Today, neither dried rhizome nor essential oil of sweet flag is allowed in food in the United States because the leading component of the essential oil is said to be carcinogenic. Dried rhizomes, however, as well as dried leaves are used in potpourris, and the dried seed heads are an interesting addition to floral arrangements.

Native Americans of the Great Lakes region weave fragrant sweet flag baskets, and those of Penobscot, Maine, believed it had protective and healing powers. Wisconsin and Minnesota Indians soak their nets in an infusion made of sweet flag and sarsaparilla, for catching white fish. It is said the net still smelled of the decoction after being in water for 12 hours.

Vapors from the roots repel some insects.

The Egyptians used sweet flag for the legendary disease of scrofula, but it should be combined with supporting, more effective herbs for this chronic condition. Originally, China and India were the motherlands of Calamus, or sweet flag, which was first taken to Russia in the 11th century when the Mongolians overcame the Russian territory. Tartars (Mongolians) considered that sweet flag purified the water. When they planned on settling in a new territory, sweet flag was always planted near the watering place to ensure of pure drinking water for the horses.

Today, sweet flag is still used for its refreshing aroma. In powdered form it is used for sachet and toilet powders. The distilled oil is used in perfumery. The candied root was a popular confection in colonial times. In medicine, it is used mainly for flavoring.
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It is particularly known for the beneficial effects on the stomach, especially heartburn with sour eructations. A few small pieces of the root being chewed and the juice swallowed, but do not swallow the pulp, will give prompt relief. The roots may be chewed several times a day for chronic conditions, until the stomach is back in good healthy working order. It stimulates the appetite and helps to relieve acute and chronic colic, gastritis, fevers, colds, sinus headaches, sinusitis, coughs, and hyperacidity, deafness, arthritis, hysteria, neuralgia, epilepsy, shock. Chewing the root is said to stop pyrosis, the discharge of an acrid liquid from the stomach into the throat. For smokers, however, chewing the dried root tends to cause mild nausea, a property that makes sweet flag useful for breaking the smoking habit. A decoction of the rootstock makes a good bath additive for insomnia, malaria, cholera, typhus, flu, bronchitis, ague, diarrhea, dysentery, asthma, a general tonic, and tense nerves; it has also been used in baths for children with scrofula or rickets. Externally, the tea is used for sores, burns, scrofula, wounds, and ulcers.
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Formulas or Dosages

Infusion: steep 1 tsp. rootstock in 1/2 cup boiling water for 5 minutes. Take 1 cup per day.

Decoction: add 1 tbsp. dried rootstock to 1 cup simmering water and boil briefly. Take 1 cup per day.

Tincture: take 10 drops, 3 times per day.

Oil: take 2 to 3 drops, 3 times per day.

Bath additive: add 1 lb. dried rootstock to 5 qt. water; bring to a boil, then steep for 5 minutes and strain. Add to the bath water.

Capsules: take 1 per day for only 1 week at a time without a break.
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Nutrient Content

Potassium, phosphorus
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How Sold

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Preparations containing beta-asarone are restricted in the United States. Beta-asarone is a carcinogen. Under FDA restrictions, not recommended for internal usage.

Sweet flag may have some toxic effects when taken internally. It is good when used externally.

Care should be taken in cases of bleeding hemorrhoids or bleeding disorders including epistaxis.
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Buy It! American Folk Medicine, by Clarence Meyer, Meyerbooks, publisher, PO Box 427, Glenwood, Illinois 60425, 1973

Buy It! Back to Eden, by Jethro Kloss; Back to Eden Publishing Co., Loma Linda, CA 92354, Original copyright 1939, revised edition 1994

Buy It! Chinese Medicinal Herbs, compiled by Shih-Chen Li, Georgetown Press, San Francisco, California, 1973.

Buy It! The Complete Medicinal Herbal, by Penelope Ody, Dorling Kindersley, Inc, 232 Madison Avenue, New York, NY 10016, First American Edition, copyright 1993

Buy It! Eastern/Central Medicinal Plants, by Steven Foster and James A. Duke., Houghton Mifflin Company, 215 Park Avenue South, New York, NY 10000

Buy It! The Herbalist Almanac, by Clarence Meyer, Meyerbooks, publisher, PO Box 427, Glenwood, Illinois 60425, copyright 1988, fifth printing, 1994

Buy It! The Herb Book, by John Lust, Bantam Books, 666 Fifth Avenue, New York, NY. copyright 1974.

Herbal Gardening, compiled by The Robison York State Herb Garden, Cornell Plantations, Matthaei Botanical Gardens of the University of Michigan, University of California Botanical Garden, Berkeley., Pantheon Books, Knopf Publishing Group, New York, 1994, first edition

Buy It! How Indians Use Wild Plants for Food, Medicine & Crafts, by Frances Densmore, Dover Publications, Inc., 180 Varick Street, New York, NY 10014, first printed by the United States Government Printing Office, Washington, in 1928, this Dover edition 1974

Buy It! Indian Herbalogy of North America, by Alma R. Hutchens, Shambala Publications, Inc., Horticultural Hall, 300 Massachusetts Avenue, Boston, Massachusetts 02115, 1973

Buy It! Secrets of the Chinese Herbalists, by Richard Lucas, Parker Publishing Company, Inc., West Nyack, NY, 1987.

Buy It! Old Ways Rediscovered, by Clarence Meyer, Meyerbooks, publisher, PO Box 427, Glenwood, Illinois 60425, published from 1954, print 1988

Buy It! The Yoga of Herbs: An Ayurvedic Guide to Herbal Medicine, by Dr. David Frawley & Dr. Vasant Lad, Lotus Press, Twin Lakes, Wisconsin, Second edition, 1988.

Buy It! Webster’s New World Dictionary, Third College Edition, Victoria Neufeldt, Editor in Chief, New World Dictionaries: A Division of Simon & Schuster, Inc., 15 Columbus Circle, New York, NY 10023

Buy It! The Rodale Herb Book: How to Use, Grow, and Buy Nature’s Miracle Plants (An Organic gardening and farming book), edited by William H. Hylton, Rodale Press, Inc. Emmaus, PA, 18049., 1974

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