The Encyclopedia of Psychoactive Plants: Ethnopharmacology and Its Applications

Acorus calamus Linnaeus


Calamus, Sweet Flag




Araceae (Arum Family)20

Forms and Subspecies


Several varieties have been described, reflecting differences in the genomes and geographical distribution (Motley 1994, 397):

Acorus calamus var. americanus (Raf.) Wulff (North America, Siberia)

Acorus calamus var. angustatus Bess. (southeast Asia, Japan, Taiwan)

Acorus calamus var. calamus L. (Eurasia)

Acorus calamus var. verus L. (tetraploid form)

Acorus calamus var. vulgaris L. (Europe, India, Himalayas)



Acorus aromaticus Gilb.

Acorus odoratus Lam.

Acorus vulgaris L.

Acorus vulgaris (Willd.) Kerner

Folk Names


Ackermagen, ackerwurtz, ackerwurz, acore, acore aromatique, acore odorant, acore vrai, acori, acoro, acoro verdadero, acrois, ajîl-i-turkî (Persian), akoron (Greek), aksir-i-turki, a-notion ao-titara, bach, bacha, bajegida (Kannada), beewort, belle angélique, bhadra (Sanskrit), bhuta-nashini (Sanskrit), boja, bojho (Nepali), bueng, calamo aromatico, calamus, canna cheirosa, chalmis, ch’ang (Chinese), ch’ang-jung, ch’ang-p’u, cinnamon sedge, dálau, dárau, déngau, deutscher ingwer, deutscher zittwer, erba cannella, erba di Venere (Italian,“plant of Venus”), flagroot, galanga des marais, ganghilovaj (Gujarati), gewürzkalmus, ghorabach, gladdon, gora vatch (Hindi), iggur, ighir jammu, jerangau, kahtsha itu (Pawnee, “medicine that lies in the water”), kalmoes, kalmuß, karmes, karmsen, kaumeles, ki we swask, kni (Egyptian), kolmas, kolmes, lubigan (Tagalog), magenwurz, Mongolian poison, moskwas’wask, muskrat root, muskwe s uwesk, musquash, myrtle flag, myrtle grass, myrtle sedge, nabuguck (Chippewa), nagenwurz, pai-ch’ang, peze boao ka (Osage, “flat plant”), pine root, pow-e-men-artic (“fire root”), rat root, reed acorus, roseau aromatique, roseau odorant, safed-bach (Hindi), schiemen, schiemenwurz, schwertenwurzel, sete, shui-ch’ang-p’u, shyobu (Japanese), sih kpetawote, sinkpe tawote (Lakota, “food of the muskrat”), sunkae (Lakota, “dog penis”), sweet calomel, sweet cane, sweet cinnamon, sweet flag, sweet flagroot, sweet grass, sweet myrtle, sweet rush, sweet segg, tatar, themeprü (Assamese), ugragandha (northern India), vaambu, vacha, vaj, vasa (Telugu), vasambu (Tamil), vash (Arabic), vashampe (Malayalam), vekhand (Marathi), venerea (Roman), venuspflanze, Venus plant, wada-kaha, warch, watchuske mitsu in, water flag, wechel, weekas, wee-kees, wehkes (“muskrat root”), wekas, wika, wike, wiken, wye (Kashmiri), yellow flag, zehrwurzrhizome, zwanenbrood (Dutch, “swan bread”)



The history of calamus is still largely unknown. It is more than questionable whether the akoron of Dioscorides was actually calamus (Schneider 1974, 1:42*). In ancient times, it was believed that akoron was indigenous to the legendary gardens of Colchis (on the Balkan Peninsula on the Black Sea). Whether calamus was used as an aphrodisiac in ancient times, as it is in modern Egypt, cannot be determined with certainty. But if the ancient names do in fact refer to calamus, then it is likely that it was used for this purpose (cf. Pliny, Natural History 25.157).21 In Italy, it is still regarded as a “plant of Venus” (Samorini and Festi 1995, 33). The “calamus” of the Bible is now interpreted as Andropogon aromaticus L. or Cymbopogon spp. (cf. Cymbopogon densiflorum). Remnants of Acorus calamus were reportedly found in the tomb of Tutankhamun (Motley 1994, 400; cf. also Germer 1985, 238f.*). It has also been suggested that calamus was an ingredient in some witches’ ointments.

Chinese sources contain what may be the oldest reference to sweet flag. The related but smaller species Acorus gramineus Soland. (p’u) was mentioned in the ancient Chinese Shih Ching, or the Book of Songs (ca. 1000–500 B.C.E.) (Keng 1974, 403*).

In Europe, sweet flag was well known during the late Middle Ages and has been esteemed as a medicinal plant since that time. It is not known whether it was present in pre-Columbian America. In any case, North American Indians became aware of its hallucinogenic effects as a result of ethnobotanical research (Motley 1994). The notion that calamus can have hallucinogenic effects was first published by Hoffer and Osmond (1967, 55f.*).



Sweet flag is apparently indigenous to Central Asia or India (Motley 1994) and is common on Sri Lanka and in the Himalayas. It has spread throughout the world as a result of cultivation (Hooper 1937, 80*). The plant was not introduced into central Europe until the sixteenth century; since then, it has established itself along creeks and slow-moving bodies of water and in lakes.


The botany of Acorus calamus was not clarified until quite recently. Its most characteristic feature is the almost phalluslike inflorescence. (Engraving from Pereira, De Beginselen der Materia Medica en der Therapie, 1849)


“A Penobscot Indian had the following dream: A muskrat told him that it was a root and where it could be found. When the man awoke, he went in search of the muskrat root and made it into a medicine. In this way, he healed his people of the plague.”








Calamus is propagated vegetatively by planting divided pieces of the rhizomes or scions with shoots. Calamus requires a marshy or very moist location. It can also survive in still water and does particularly well along the moist margins of ponds.

In North America, the muskrat (Ondatra zibethica) appears to have played a substantial role in increasing the range and occurrence of the plant. The animal is “magically” attracted to the rhizome and not only eats the rhizomes of the fresh plant but also collects parts of these and stores them for future use. Under the proper conditions, these pieces may then produce new roots. It is possible that the muskrat’s characteristic scent may be due in no small part to its consumption of calamus (Morgan 1980, 237).



Calamus is a perennial plant that may grow as tall as 120 cm. The rootstock (rhizome) spreads by creeping. The light to lushly green leaves are gladiate (like a sword blade) and distichous (in two rows). Rubbing them releases the typical calamus scent. The tiny, inconspicuous yellow-green flowers are attached to a spadix 5 to 8 cm in length. In its area of origin (India), sweet flag blossoms from April to June; in central Europe, from June to July.

The very similar but considerably smaller species Acorus gramineus Soland. is found throughout Asia. It is easily recognized by its very small leaves (10 to 20 cm in length), which also exude the typical calamus aroma when rubbed.

In North America, calamus is often confused with Iris pseudacorus L., commonly known as yellow flag, and Iris versicolor L., known as blue flag (Motley 1994, 400).

Psychoactive Material


—Rhizome (rhizoma calami, calami rhizoma, calamus root)

—Calamus oil (calami aetheroleum, oleum calami)

Preparation and Dosage


Calamus oil is used as an aromatic additive to snuff powders and snuffing tobacco (see Nicotiana tabacum) (Hooper 1937, 80*) and in alcoholic beverages (spirits, alcoholbeer) (Motley 1994, 398).

A tea (infusion or decoction) from chopped rootstock (1 teaspoon per cup) can be drunk to treat feelings of weakness, nervousness, and stomach and intestinal cramps and as a nervine or aphrodisiac (Frohne 1989). A strong decoction can also be used as a bath additive. Calamus is an ingredient in many bitter cordials (cf. theriac).

According to some North American Indians, an amount of calamus equivalent in size to a finger is sufficient to produce psychoactive effects. However, very high dosages (200 to 300 g of dried roots) have also been tested.

Ritual Use


In ancient China, calamus was clearly used in shamanism. However, this may have been the smaller species (Acorus gramineus Soland. or Acorus gramineus Soland. var. pusillus (Sieb.) Engl.) known as ch’ang-p’u (also shi chang pu). Mêng Shen wrote:


Those who wish to see spirits use the raw ma fruits [Cannabis sativa], ch’ang-p’u [Acorus gramineus], and k’uei-chiu [Podophyllum pleianthum Hance, syn. Dysosma pleiantha (Hance) Woods.; cf. Podophyllum peltatum], ground in equal amounts, and make these into pills the size of a marble and take these every day when they look into the sun. After a hundred days, they will be able to see spirits. (Li 1978, 23*)


In China, calamus is one of the oldest auspicious plants. It is said that the Taoist An-ch’isheng used wild calamus as an elixir, which caused him to become not only immortal, but invisible as well. Unfortunately, the methods of preparing and ingesting calamus for this purpose have not been passed down to us. Bundles of calamus leaves, together with Artemisia vulgaris (cf. Artemisia spp.), are still used as talismans during the dragon boat festival, and they are hung over the house door to protect against evil spirits (Motley 1994, 402).


The small Chinese relative of calamus (Acorus gramineus).



The characteristic inflorescence of calamus (Acorus calamus).


In Kashmir, the root is regarded as auspicious and should be the first thing a person looks upon on the morning of the traditional new year’s festival (navroj) (Shah 1982, 299*). Indian snake charmers use pieces of calamus root to charm cobras (Motley 1994, 403).

Many North American Indians regard calamus as a panacea and tonic. The Iroquois used the root to detect witches and evil magic. Many Indians of the Northeast woodlands believe that the root has apotropaic effects and consequently hang it in the house or sew it into their children’s clothing. The “spirits of the night” (nightmares) then stay away. The Winnebago, Ponca, Pawnee, Omaha, and Dakota make garlands of calamus grass that are used in secret rites (wakan wacipi, “sacred dance”) and as hunting talsimans (Howard 1953; Morgan 1980, 235). The Chippewa combine calamus with Aralia nudicaulis L. and then boil a decoction in which they soak their fishing nets to ensure a good catch or to chase away rattlesnakes (Motley 1994, 404).

The Cheyenne use calamus roots as incense in their sweat lodge ceremonies. They simply toss pieces of the root onto the glowing stones in the sweat lodge. The smoke is said to be cleansing and beneficial to health. Pieces of calamus root as well as calamus leaves are also occasionally added to smoking mixtures or mixed with tobacco (Nicotiana spp.) (cf. kinnikinnick).

The Cree reputedly used calamus roots as a hallucinogen. It is said that they chewed a piece of root as long as a finger. The accuracy of this information, which has been repeated often in the psychedelic literature, is somewhat in doubt (cf. Morgan 1980; Ott 1993*; Schultes and Hofmann 1995*), as all experiments with American calamus—even those involving very high dosages (up to 300 g of rhizomes!)—have been completely unsuccessful. If the Cree did indeed possess a hallucinogen, it probably was not Acorus calamus. One Cree name for calamus—or, as the source notes, a very similar plant—is pow-e-men-artic, “fiery pepper root.” The Cree frequently placed pieces of calamus root, which they called wee-kees (muskrat root), in their medicine bundles (Johnston 1970, 308*).

Amazingly, several evangelical churches in Lutheran parishes burned calamus in the 1950s as an incense during Easter (Motley 1994, 402).



A section of naturalist North American poet Walt Whitman’s (1819–1892) renowned collection of poems Leaves of Grass bears the heading “Calamus.” It is possible that the poems contained within this section were inspired by calamus or its effects (Morgan 1980, 235f.).

Medicinal Use


In the Ayurvedic system of medicine, calamus is used to treat sleeplessness, melancholy, neuroses, epilepsy, hysteria, memory loss, and fever (Vohora et al. 1990, 53). Calamus is used together with saffron (see Crocus sativus) and milk to induce labor (Motley 1994, 403). Nepali Sherpas use a paste made from fresh rootstock as an antiseptic agent to treat wounds in animals (Bhattarai 1989, 47*). The Nepalis use the root for colds and coughs (Manandhar 1980, 9*) and as a tonic for the nerves (Singh et al. 1979, 188*). In Ayurvedic and Tibetan medicine, calamus is an important psychoactive plant: “Vacha literally means ‘speak’ and describes the power of the word, the intelligence, or the self-expression that is stimulated by this medicinal plant” (Lad and Frawley 1987, 175*).


Calamus is an exotic plant that is also commonly referred to as sweet flag. For centuries, it was known in the West only in the form of its rhizome. Herbals listed it under the name “Acorus of the apothecaries.” The illustrations in these books were based primarily upon the artists’ imaginations. (Woodcut from Lonicerus, Kreuterbuch, 1679)


It is for this reason that calamus root, when used as incense, has the effect of illuminating and strengthening the mind. It is often found in Tibetan incense mixtures that are burned to strengthen the nerves and to increase meditative concentration. It is also regarded as a rejuvenation tonic and as “nourishment for the Kundalini serpent” (Lad and Frawley 1987, 176*).

In the forest regions and neighboring plains of North America, calamus is a medicine that the Indians use for a great number of purposes. Decoctions of the root are used to treat stomach and intestinal ailments, digestive difficulties, and cramps. Fresh pieces of the root are chewed for headaches, colds, sore throats, and bronchitis. Dried, the root is also used to prepare a medicinal and ritual snuff (Morgan 1980).

Calamus is smoked or burned as incense to treat headaches, coughs, and colds (Motley 1994, 404). The Blackfeet, who obtained calamus roots via long trade routes, used it as an abortifacient. The root was chewed as a cure-all. To treat headaches, the Blackfeet would burn a mixture of ground root and tobacco (Nicotiana spp.) and inhale the smoke (Johnston 1970, 307f.*). The Chippewa manufactured a medicine from calamus root, the bark of Xanthoxylum americanum Mill., the root cortex of Sassafras albidum, and the root of Asarum canadense L.22 to treat colds and bronchitis (Morgan 1980, 240).

In traditional Chinese medicine, the rootstock of Acorus gramineus is used to treat forgetfulness, lack of concentration, hearing difficulties, buzzing in the ears, epilepsy, mental illnesses, sensations of being full in the stomach, and gastritis (Paulus and Ding 1987, 128*).



Calamus root contains high levels of essential oil with decadienal, caryophyllene, humulene, curcumene, and β-asarone as well as the bitter principles acorone, neoacorone, and acorine, tanning agents, and mucilage (Chinese calamus contains α-asarone and β-asarone as well as eugenol, safrole, α-humulene, sekishone, etc.). The essential oil of Acorus calamus var. americanus is devoid of β-asarone (Motley 1994, 407). Plants from India contain especially high concentrations of asarone (Baxter et al. 1960; Vohora et al. 1990). Indian plants have also been reported to produce psychotropic effects (Motley 1994, 405).



“In paths untrodden,

In the growth by margins of pond-waters,

Escaped from the life that exhibits itself,

From all the standards hitherto publish’d, from the pleasures, profits, conformities,

Which too long I was offering to feed my soul,

Clear to me now standards not yet publish’d, clear to me that my soul,

That the soul of the man I speak for rejoices in comrades,

Here by myself away from the clank of the world,

Tallying and talk’d to here by tongues aromatic. . . .”









The yellow gladiolus was once known as Acorus vulgaris, or common calamus. This was intended to distinguish it from the “calamus of the apothecaries,” the true calamus. (Woodcut from Fuchs, Läebliche abbildung und contrafaytung aller kreüter, 1545)


The rhizomes of Acorus gramineus contain high amounts of essential oil, consisting of αasarone, β-asarone, eugenol, safrole, α-humulene, sekishone, and other constituents (Paulus and Ding 1987, 128*).



Asarone is regarded as the inebriating principle in the raw drug23 (Baxter et al. 1960; Motley 1994, 399). Laboratory experiments have verified its effects upon the central nervous system (Vohora et al. 1990). It also has inebriating effects, which are presumably due to a metabolite, TMA or trimethylmethamphetamine (cf. Myristica fragrans). The essential oil has tonic effects, strengthens the stomach, and relieves cramps. It also has antibacterial effects. β-asarone is also reputed to have toxic and carcinogenic effects. Pharmacologically, asarone is said to act in a manner similar to papaverine (Motley 1994, 405).







The assertion that calamus is hallucinogenic appears to be due more to wishful thinking than to actual experiences with the plant. Even with very high dosages (up to 100 g of decocted, dried rhizomes), I have been unable to detect any type of hallucinogenic, psychedelic, entheogenic, or other visionary effect. Instead, the effects of asarone appear to be more sedative in nature. I also am unaware of any experimentally inclined psycho-nauts who have been able to report successful experiments with calamus. In my opinion, calamus can be stricken from the list of so-called legal highs, at least until new evidence of its psychoactivity appears.

Commercial Forms and Regulations


Calamus root (rhizoma calami) can be obtained in herb shops and pharmacies. Calamus oil has been taken off the market because of its (doubtful) carcinogenic effects (Motley 1994, 407). In Germany, calamus is allowed to be used as an aromatic agent for schnapps and similar items as long as the amount of asarone per liter of the beverage it is added to does not exceed 1 mg (Roth et al. 1994, 92*).



See also the entry for essential oil.


Abel, Gudrun. 1987. “Chromosomenschädigende Wirkung von β-asaron in menschlichen Lymphocyten.” Planta Medica 53:251–53.


Baxter, R. M., P. C. Dandiya, S. I. Kandel, A. Okany, and G. C. Walker. 1960. Separating of hypnotic potentiating principles from the essential oil of Acorus calamus L. of Indian origin by gas-liquid chromatography. Nature 185:466–67.


Frohne, Dietrich. 1989. Kalmuswurzelstock. In Teedrogen, ed. M. Wichtl, 260–62. Stuttgart: WVG.


Grayum, M. H. 1987. A summary of evidence and arguments supporting the removal of Acorus from the Araceae. Taxon 36:723–29.


Howard, James. 1953. Notes on two Dakota “holy dance” medicines and their uses. American Anthropologist 55:608–9.


Morgan, George R. 1980. The ethnobotany of sweet flag among North American Indians. Botanical Museum Leaflets 28 (3): 235–46.


Motley, Timothy J. 1994. The ethnobotany of sweet flag, Acorus calamus (Araceae). Economic Botany 48 (4): 397–412. (Very good bibliography.)


Samorini, Giorgio, and Francesco Festi. 1995. Acorus calamus L. (calamon aromatico). Eleusis 1:33–36.


Speck, Frank G. 1917. Medicine practices of the northeastern Algonquians. In Proceedings of the Nineteenth International Congress of Americanists (Washington, D.C.): 303–21.


Vohora, S. B., Shaukat A. Shah, and P. C. Dandiya. 1990. Central nervous system studies on an ethanol extract of Acorus calamus rhizomes. Journal of Ethnopharmacology 28:53–62.


Whitman, Walt. 1900. Leaves of grass. Philadelphia: David McKay.