Sweet Flag

Sweet Flag

There are two, possibly more, species of rhizomatous, aquatic perennials in this genus, which are found wild in N and E Asia, and N America. Variegated forms are popular ornamentals: the larger ones for waterside planting and dwarf varieties as pot plants or aquarium plants. Sweet flag (A calamus) has been cultivated and traded for over 4,000 years, probably reaching eastern Europe from Mongolia and Siberia during the 13th century, and spreading to western Europe in the 16th century. It was once important as a strewing herb and grown in large quantities in the Norfolk Broads in England, where it was gathered at an annual "gladdon harvest". Calamus candy, made by crystalizing tender slices of the rhizome, was popular in the 18th century as a medicinal lozenge to cure coughs and indigestion, and to ward off infection. There are several distinct populations of A. calamus in the wild, differing in genetic conformation and in important details of chemistry. Some botanists regard these as separate species. All contain 1-4 percent of volatile oil (oil of calamus) in the rhizome. The constituents of the oil may include asarone, a tranquilizing and antibiotic compound that is potentially toxic and carcinogenic. Oil from populations in N America and Siberia is asarone-free. Oil of calamus is banned by the US Food and Drug Administration. Doubts about its safety had led to withdrawal from general sale in other countries, including Great Britain, and use is restricted in Australia and New Zealand. Acorus gramineus was first mentioned as a medicinal herb in China during the Song dynasty (c.11-12th century).

Calamus is a tall, reedy wetland plant whose long, scented aromatic rhizomes are used for medicinal purposes and as a psychotropic drug. It has been said that 5 cm of dried calamus rhisome, either chewed or chopped and prepared as a tea, is "stimulating and evokes a cheerful mood," while 25cm can lead to hallucinations. Calamus is also reputed to be an aphrodisiac, especially when added to bathwater.

Semi-evergreen perennial with citrus-scented rhizomes and arching, strap-shaped, tapering leaves to 1.5m (5ft) long. A solitary spadix, 6-8cm (2-3in) long, bearing minute yellow-green flowers, appears in summer on a flowering stem that resembles a leaf.

Acorus is a grasslike, rhizome-forming perennial plant resembling an iris. It inhabits wet areas like the edges of streams ans around ponds and lakes. The rhizomes have an aromatic, spicy fragrance, and are used in herbal medicine. Acorus is the Japanese relative of the American herb calamus, also known as sweetflag.

Common Name:
Sweet Flag
Other Names:
Acorus, Calamus, Chang Pu, Cinnamon Sedge, Gramineus, Myrtle Flag, Shi Chang Pu, Sweet Cane, Sweet Myrtle, Sweet Rush, Sweet Sedge.
Botanical Name:
Acorus calamus
E Asia and N America, naturalized in Europe
Wet soil or shallow water up to 25cm (10in) deep in a sunny position. Acorus gramineus 'Pusillus' can be grown as a submerged aquatic. Plants grown in aquariums deteriorate if submerged for long periods, especially if grown in tropical conditions. Divide large clumps every 3-4 years to maintain vigor.
By division of rhizomes in early spring.
Plants are lifted at any time, except during the flowering period. The required amount of rhizome is cut and the remainder replanted. The rhizome may be dried for use in decoctions, distilled for oil (A. calamus), or used fresh for tinctures, liquid extracts, pastes, and powders.
90cm (36in)
Creamed-striped leaves, pink at the base.
Height: 60-90cm (24-36in)
Width: 60cm (24in)
Parts Used:
Rhizomes, oil
An aromatic, bitter, stimulant herb that relaxes spasms and relieves indigestion.
Medicinal Uses:
Internally for digestive complaints, bronchitis, and sinusitis. Externally for skin eruptions, rheumatic pains, and neuralgia. An important herb in Ayurvedic medicine, regarded as a restorative for the brain and nervous system, especially after a stroke; also given for bronchial complaints and bleeding disorders. Combined with Elettaria cardamomum (see Cardamom) to help digestion of dairy products. Used as snuff for nasal congestion, polyps, shock and coma. Excess causes vomiting.
To treat ulcers, rheumatism, toothache, pain syndrome, gastrointestinal disorders, gum disease, tonsilitis, and fungal infections.
Evidence of Benefit:
Acorus is an antioxidant that has special effects on the central nervous system. It is used by the Akha people of Thailand for stomachache. The Chinese use it for vomiting, diarrhea, abdominal pain, and dysentery. This herb eliminates phlegm and tranquilizes the mind, and has been used to treat amnesia, heart palpitations, insomnia, tinnitus, chronic bronchitis, and bronchial asthma.
Benefits of acorus for specific health conditions include the following:
  • Drug Withdrawal: Acorus affects the brain during withdrawal from cocaine, heroin, and morphine. During the first one to ten days of withdrawal, addicts experience intense drug cravings, nausea and vomiting. Acorus can blunt gastric upset during the acute phase of drug withdrawal (although it has no effect on the cravings themselves) through its ability to prevent the secretion of the inflammatory chemical histimine.
  • Seizure Disorders: Acorus is used to treat a broad range of brain conditions. It works by protecting brain tissue from toxic free radicals, which are released in the presence of excess oxygen. When the flow of oxygen is restored to previously oxygen-deprived brain cells, these cells are temporarily unable to use all the oxygen available to them. The oxygen escapes the biochemical pathway that usually control it and free-radical damage results. The resulting tissue damage in the brain can lead to memory loss or seizures. Acorus helps prevent the formation of free-radicals of oxygen and the resulting brain tissue damage. It is most effective when taken before circulation is restored, that is, in the first few days to a month after head injury or stroke.
Consideration for Use:
Acorus is most commonly supplied by practitioners of traditional Chinese medicine (TCM). It is usually sold in the United States as Chang Pu, or Shi Chang Pu, in the form of powder, teas, and tinctures.
The herb's American relative calamus contains the potentially cancer-causing chemical beta-asarone, which has caused it to be banned for use in the United States. Although the form of Acorus used in TCM is legal in the United States, it is restricted in Canada. Many other countries ban the use of both acorus and calamus in herbal medicine. Acorus should never be used without professional supervision.
Possible Side Effects:
No side effects or health hazards are known when calamus is taken in designated therapeutic dosages. However, rats receiving calamus oil over an extended period of time developed malignant tumors; therefore, long-term use of calamus should probably be avoided.
Drug Interactions:
Taking calamus with these drugs may interfere with the action of the drug:
Aluminum Hydroxide, (AlternaGel, Alu-Cap) Aluminum Hydroxide and Magnesium Carbonate, (Gaviscon Extra Strength, Gaviscon Liquid) Aluminum Hydroxide and Magnesium Hydroxide, (Maalox, Rulox) Aluminum Hydroxide and Magnesium Trisilicate, (Gaviscon Tablet)
Aluminum Hydroxide, Magnesium Hydroxide, and Simethicone, (Maalox, Mylanta Liquid) Calcium Carbonate, (Rolaids Extra Strength, Tums) Calcium Carbonate and Magnesium Hydroxide, (Mylanta Gelcaps, Rolaids Extra Strength) Cimetidine, (Nu-Cimet, Tagamet)
Esomeprazole, (Nexium) Famotidine, (Apo-Famotidine, Pepcid) Famotidine, Calcium Carbonate, and Magnesium Hydroxide, (Pepcid Complete) Lansoprazole, (Prevacid)
Magaldrate and Simethicone, (Riopan Plus, Riopan Plus Double Strength) Magnesium Hydroxide, (Dulcolax Milk of Magnesia, Phillips' Milk of Magnesia) Magnesium Oxide, (Mag-Ox 400, Uro-Mag) Magnesium Sulfate, (Epsom Salts)
Nizatidine, (Axid, PMS-Nizatidine) Omeprazole, (Losec, Prilosec) Pantoprazole, (Pantoloc, Protonix) Rabeprazole, (Aciphex, Pariet)
Ranitidine, (Alti-Ranitidine, Zantac)
Sodium Bicarbonate, (Brioschi, Neut)
Taking calamus with these drugs may increase the drug's therapeutic and adverse effects:
Iproniazid, (Marsilid) Moclobemide, (Alti-Moclobemide, Nu-Moclobemide)
Phenelzine, (Nardil) Selegiline, (Eldepryl)
Tranylcypromine, (Parnate)
Supplement Interactions:
May enhance therapeutic and adverse effects of herbs and supplements that have sedative properties, such as 5-HTP, Kava Kava, St. John's Wort, and Valerian.
Economic Uses:
Calamus oil is used to flavor liqueurs, bitters, soft drinks, cordials and vinegar.
Subject to legal restrictions in some countries, especially as oil of calamus.
Encylopedia of Herbs by Deni Brown Copyright ©: 1995, 2001 Dorling Kindersley Limited pg 101
The Essential Herb-Drug-Vitamin Interaction Guide by Geo. T. Grossberg,MD and Barry Fox,PhD Copyright©2007 Barry Fox,PhD. Pp.114-116
Prescription for Herbal Healing by Phyllis A. Balch, CNC. Copyright©2002 Phyllis A. Balch pg. 14