| Common Sweet Flag | |
|---|---|
| Sweet flag | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Monocots |
| Order: | Acorales |
| Family: | Acoraceae |
| Genus: | Acorus |
| Species: | A. calamus |
| Binomial name | |
| Acorus calamus L. |
|
Acorus calamus, commonly known as Sweet Flag[1] or Calamus,[1] and erroneously as "rush" or "sedges", is a tall perennial wetland monocot of the Acoraceae family, in the genus Acorus.[2] Other names include beewort,[1] bitter pepper root,[1] calamus root,[1] flag root,[1] gladdon, myrtle flag, myrtle grass,[1] myrtle root,[1] myrtle sedge,[1] pine root,[1] sea sedge,[1] sweet cane, sweet case,[1] sweet cinnamon,[1] sweet grass,[1] sweet myrtle,[1] sweet root, sweet rush,[1] and sweet sedge.[1] The scented leaves and more strongly scented rhizomes have traditionally been used medicinally and to make fragrances, and the dried and powdered rhizome has been used as a substitute for ginger, cinnamon and nutmeg.[2][3]
Probably indigenous to India or Arabia, Acorus calamus is now found across Europe, southern Russia, northern Asia Minor, southern Siberia, China, Indonesia, Japan, Burma, Sri Lanka, Australia, as well as southern Canada and the northern United States,[2][3] where it may be confused with diploid Acorus americanus.[4]
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The morphological distinction between the Acorus species is made by the number of prominent leaf veins. Acorus calamus has a single prominent midvein and then on both sides slightly raised secondary veins (with a diameter less than half the midvein) and many fine tertiary veins. This makes it clearly distinct from Acorus americanus.
The leaves are between 0.7 and 1.7 cm wide, with average of 1 cm. The sympodial leaf of Acorus calamus is somewhat shorter than the vegetative leaves. The margin is curly-edged or undulate. The spadix, at the time of expansion, can reach a length between 4.9 and 8.9 cm (longer than A. americanus). The flowers are longer too, between 3 and 4 mm. Acorus calamus is infertile and shows an abortive ovary with a shriveled appearance.
Acorus americanus was formerly classified as Acorus calamus var. americanus. It differs in being a fertile diploid (2n = 24)], whereas most of the A. calamus of Europe and Asia is a sterile triploid species, that only spreads asexually. Diploid plants in northern Asia may be part of A. americanus.[4] Also as a diploid it does not produce b-asarone.
One subspecies, Acorus calamus var. angustatus Besser, Synonyms: Acorus asiaticus, Acorus cochinchinensis, Acorus latifolius, Acorus rumphianus, Acorus spurius, Acorus triqueter, Acorus tatarinowii, Acorus terrestris, Orontium cochinchinense, Acorus calamus var. spurius, Acorus gramineus var. crassispadix.
A. calamus and products derived from A. calamus (such as its oil) were banned in 1968 as food additives and medicines by the United States Food and Drug Administration.[5] This ban was the result of lab studies that involved supplementing the diets of lab animals over a prolonged period of time with massive doses of isolated chemicals (β-asarone) from the Indian Jammu strain of calamus. The animals developed tumors, and the plant was labeled procarcinogenic.[6][7] Wichtl says “It is not clear whether the observed carcinogenic effects in rats are relevant to the human organism.”[8] However, most sources advise caution in ingesting strains other than the diploid strain.
Four varieties of Acorus calamus strains exist in nature; diploid, triploid, tetraploid and hexaploid.[9] Diploids do not produce the procarcinogenic β-asarone. Diploids are known to grow naturally in Eastern Asia (Mongolia and Central Siberian Plateau) and North America. The triploid cytotype probably originated in the Himalayan region, as a hybrid between the diploid and tetraploid cytotypes.[10] The North American Calamus is known as Acorus Calamus var. Americanus or more recently as simply Acorus Americanus. Like the diploid strains of calamus in parts of the Himalayas, Mongolia, and C Siberia, the North American diploid strain does not contain the procarcinogenic β-asarone.[11][12][13] Research has consistently demonstrated that “β-asarone was not detectable in the North American spontaneous diploid Acorus [Calamus var. Americanus]”.[14]
In reality β-asarone is not actually a carcinogen but it is a procarcinogen that is neither hepatotoxic nor directly hepatocarcinogenic. It must first undergo metabolic l'-hydroxylation in the liver before achieving toxicity. Cyrochrome P450 in the hepatocytes is responsible for secreting the hydrolyzing enzymes that convert β-asarone into genotoxic epoxide structure.[15] Even with the activation of these metabolites, the carcinogenic potency is very low due to the rapid breakdown of epoxide residues with hydrolase which leaves these compounds inert (Luo, 1992). Additionally, the major metabolite of β-asarone is 2,4,5-trimethoxyninnamic acid, a derivative which is not a carcinogen (Hasheminejad & Caldwell, 1999).
A. Calamus has been an item of trade in many cultures for thousands of years. It has been used medicinally for a wide variety of ailments, and its aroma makes calamus essential oil valued in the perfume industry. In Britain the plant was also cut for use as a sweet smelling floor covering for the packed earth floors of medieval dwellings and churches, and stacks of rushes have been used as the centrepiece of rushbearing ceremonies for many hundreds of years.[16] It has also been used as a thatching material for English cottages.[17]
In antiquity in the Orient and Egypt, the rhizome was thought to be a powerful aphrodisiac. In Europe Acorus calamus was often added to wine, and the root is also one of the possible ingredients of absinthe. Among the northern Native Americans, it is used both medicinally and as a stimulant. It is believed by some that calamus is a hallucinogen. This urban legend is based solely on two pages of a book written by Hoffer and Osmund entitled The Hallucinogens. The information on these two pages came from anecdotal reports from two individuals (a husband and wife) who reported that they had ingested calamus on a few occasions.[7][18] None of the components in calamus are converted to TMA (trimethoxyamphetamine) in the human organism.[18] To date there is no solid evidence of any hallucinogenic substances in calamus. Acorus calamus shows neuroprotective effect against stroke and chemically induced neurodegeneration in rat. Specifically, it has protective effect against acrylamide induced neurotoxicity.[19]
The essence from the rhizome is used as a flavor for pipe tobacco. When eaten in crystallized form, it is called "German ginger". It's also used in bitters.[3]
For the Penobscot people this was a very important root. One story goes that a sickness was plaguing the people. A muskrat spirit came to a man in dream, telling him that he (the muskrat) was a root and where to find him. The man awoke, found the root, and made a medicine which cured the people. In Penobscot homes, pieces of the dried root were strung together and hung up for preservation. Steaming it throughout the home was thought to "kill" sickness. While traveling, a piece of root was kept and chewed to ward off illness.[20]
Teton-Dakota warriors chewed the root to a paste, which they rubbed on their faces. It was thought to prevent excitement and fear when facing an enemy.[20]
The Potawatomi people powdered the dried root and placed this up the nose to cure catarrh.[20]
Sweet flag has a very long history of medicinal use in Chinese and Indian herbal traditions.[21] It is widely employed in modern herbal medicine as its sedative, laxative, diuretic, and carminative properties.[3] It is used in Ayurveda to counter the side effects of all hallucinogens.[22] Sweet Flag is one of the most widely and frequently used herbal medicines amongst the Chipewyan people.[23]
Both roots and leaves of A. calamus have shown antioxidant,[24] antimicrobial and insecticidal activities.[25]
Acorus calamus may prove to be an effective control measure against cattle tick, Rhipicephalus (Boophilus) microplus.[26]
Both triploid and tetraploid A. calamus contain alpha-asarone.[3] Other phytochemicals include:
Diploids do not contain beta-asarone (β-asarone).[14] A recent study showed that beta-asarone isolated from Acorus calamus oil inhibits adipogenesis in 3T3-L1 cells and thus reduces lipid accumulation in fat cells.[31]
The calamus has long been a symbol of love. The name is associated with a Greek myth: Kalamos, son of the river-god Maeander, who loved the youth Karpos, of Zephyrus (the West Wind) and Chloris (Spring). When Karpos drowned in a swimming race, Kalamos also drowned and was transformed into a reed, whose rustling in the wind was interpreted as a sigh of lamentation.
The plant was a favorite of Henry David Thoreau (who called it "sweet flag"), and also of Walt Whitman, who added a section called the "Calamus" poems, to the third edition of Leaves of Grass (1860). In the poems the calamus is used as a symbol of love, lust, and affection.
The name Sweet Flag refers to its sweet scent (it has been used as a strewing herb) and the wavy edges of the leaves which are supposed to resemble a fluttering flag.
Cognates of the Latin word calamus (meaning "cane") are found in both Greek (kalamos, meaning "reed") and Sanskrit (kalama, meaning "reed" and "pen" as well as a sort of rice) — strong evidence that the word is older than all three languages and exists in their parent language, Proto-Indo European. The Arabic word qalam (meaning "pen") is likely to have been borrowed from one of these languages in antiquity, or directly from Indo-European itself.
From the Latin root "calamus", a number of modern English words arise: