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Acorus calamus - L.

Sweet Flag

Author	L.	Botanical references	200, 266
Family	Araceae	Genus	Acorus
Synonyms
Known Hazards	The fresh root can be poisonous[7]. When using the plant medicinally, the isolated essential oil should not be used[165]. The essential oil in the roots of some populations of this plant contains the compound asarone. This has tranquillising and antibiotic activity, but is also potentially toxic and carcinogenic[218, 238]. It seems that these compounds are found in the triploid form of the species (found in Asia) whilst the diploid form (found in N. America and Siberia) is free of the compounds[218, 238]. However, the root (but not the isolated essential oil) has been used in India for thousands of years without reports of cancer which suggests that using the whole herb is completely safe, though more research is needed[254].
Range	Europe, Asia and N. America. Naturalized in Britain[17].
Habitat	Found in moist soils and shallow water in ditches, marshes, river edges and ponds[1, 100, 187, 244].
Edibility Rating	3 (1-5)	Medicinal Rating	4 (1-5)

Physical Characteristics

Perennial growing to 1m by 1m.

The plant prefers light (sandy), medium (loamy) and heavy (clay) soils. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires wet soil and can grow in water.

Habitats

Pond; Bog Garden;

Edible Uses

Edible Parts: Leaves; Root; Stem.

Edible Uses: Condiment.

The rhizome is candied and made into a sweetmeat[2, 4, 13, 55, 62, 115, 183]. It can be peeled and washed to remove the bitterness and then eaten raw like a fruit[106, 179]. It makes a palatable vegetable when roasted[192] and can also be used as a flavouring[61]. Rich in starch, the root contains about 1% of an essential oil that is used as a food flavouring[1, 13, 57]. The root also contains a bitter glycoside[179]. Some caution is advised, see the notes above on toxicity. The dried and powdered rhizome has a spicy flavour and is used as a substitute for ginger, cinnamon and nutmeg[4, 55, 142, 177, 183]. A pinch of the powdered rhizome is used as a flovouring in tea[272]. The young and tender inflorescence is often eaten by children for its sweetness[4]. Young leaves - cooked[55]. The fresh leaves contain 0.078% oxalic acid[240]. The leaves can be used to flavour custards in the same way as vanilla pods[244]. The inner portion of young stems is eaten raw[62]. It makes a very palatable salad[183].

Medicinal Uses

Abortifacient; Anodyne; Aphrodisiac; Aromatic; Carminative; Diaphoretic; Emmenagogue; Febrifuge; Hallucinogenic; Homeopathy; Odontalgic; Sedative; Stimulant; Stomachic; Tonic; Vermifuge.

Sweet flag has a very long history of medicinal use in many herbal traditions. It is widely employed in modern herbal medicine as an aromatic stimulant and mild tonic[4]. In Ayurveda it is highly valued as a rejuvenator for the brain and nervous system and as a remedy for digestive disorders[254]. However, some care should be taken in its use since some forms of the plant might be carcinogenic - see the notes above on toxicity for more information. The root is anodyne, aphrodisiac, aromatic, carminative, diaphoretic, emmenagogue, expectorant, febrifuge, hallucinogenic, hypotensive, sedative, stimulant, stomachic, mildly tonic and vermifuge[4, 7, 9, 21, 147, 165, 213, 240, 279]. It is used internally in the treatment of digestive complaints, bronchitis, sinusitis etc[238]. It is said to have wonderfully tonic powers of stimulating and normalizing the appetite. In small doses it reduces stomach acidity whilst larger doses increase stomach secretions[254] and it is, therefore, recommended in the treatment of anorexia nervosa[244]. However if the dose is too large it will cause nausea and vomiting[K]. Sweet flag is also used externally to treat skin eruptions, rheumatic pains and neuralgia[238]. An infusion of the root can bring about an abortion[213] whilst chewing the root alleviates toothache[213]. It is a folk remedy for arthritis, cancer, convulsions, diarrhoea, dyspepsia, epilepsy etc. Chewing the root is said to kill the taste for tobacco[218]. Roots 2 - 3 years old are used since older roots tend to become tough and hollow[4]. They are harvested in late autumn or early spring and are dried for later use[4]. The dry root loses 70% of its weight, but has an improved smell and taste[244]. It does, however, deteriorate if stored for too long[244]. Caution is advised on the use of this root, especially in the form of the distilled essential oil, since large doses can cause mild hallucinations[192]. See also the notes above on toxicity. A homeopathic remedy is made from the roots[9]. It is used in the treatment of flatulence, dyspepsia, anorexia and disorders of the gall bladder[9].

Other Uses

Basketry; Incense; Insecticide; Repellent; Strewing; Thatching; Weaving.

The leaves are used in basket making or woven into mats[169]. They have also been used as a thatch for roofs[4]. An essential oil from the rhizome is used in perfumery and as a food flavouring[1, 13, 57]. The oil is contained mainly in the outer skin of the root[245], it has a fragrance reminiscent of patchouli oil[192]. The fresh roots yield about 1.5 - 3.5% essential oil, dried roots about 0.8%[4, 240]. Some plants from Japan have yielded 5% essential oil[4]. The essential oil is also an insect repellent and insecticide[218, 272]. It is effective against houseflies[240]. When added to rice being stored in granaries it has significantly reduced loss caused by insect damage because the oil in the root has sterilized the male rice weevils[244]. An essential oil obtained from the leaves is used in perfumery and for making aromatic vinegars[245]. The leaves and the root have a refreshing scent of cinnamon[245]. All parts of plant can be dried and used to repel insects or to scent linen cupboards[8, 14, 61]. They can also be burnt as an incense[14], whilst the whole plant was formerly used as a strewing herb[4, 14, 115, 238]. The growing plant is said to repel mosquitoes[20, 201].

Scented Plants

Leaves: Crushed

A refreshing scent of cinnamon.

Root: Crushed

The root has a refreshing scent of cinnamon.

Cultivation details

Prefers growing in shallow water or in a very moist loamy soil[200]. Requires a sunny position[200]. Prefers a pH in the range 5.5 to 7.5. Plants are hardy to about -25°c[187]. The sweet flag has a long history of use as a medicinal and culinary plant. It has been cultivated for this purpose but was more commonly allowed to naturalize and was then harvested from the wild. The plant seldom flowers or sets seed in Britain and never does so unless it is growing in water[4]. It can spread quite freely at the roots however and soon becomes established.

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Stand the pot in about 3cm of water. Pot up young seedlings as soon as they are large enough to handle, keep them wet by standing the pots in shallow water and overwinter for the first year in a greenhouse or cold frame. Seed is rarely produced in Britain[4, 17]. Division in spring just before growth starts[1]. Very easy, it can be carried out successfully at any time in the growing season and can be planted direct into its permanent positions[K].

Cultivars

No entries have been made for this species as yet.

Links

This plant is also mentioned in the following PFAF articles: The Edible Pond and Bog Garden.

Permaculture.info Details of this plant in the Permaculture.info project, a community plant and permaculture database.

References

[K] Ken Fern
Notes from observations, tasting etc at Plants For A Future and on field trips.

[1] F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaces in 1992 by a new dictionary (see [200]).

[2] Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972 ISBN 0-486-20459-6
Lots of entries, quite a lot of information in most entries and references.

[4] Grieve. A Modern Herbal. Penguin 1984 ISBN 0-14-046-440-9
Not so modern (1930's?) but lots of information, mainly temperate plants.

[7] Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984 ISBN 0-356-10541-5
Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.

[8] Ceres. Free for All. Thorsons Publishers 1977 ISBN 0-7225-0445-4
Edible wild plants in Britain. Small booklet, nothing special.

[9] Launert. E. Edible and Medicinal Plants. Hamlyn 1981 ISBN 0-600-37216-2
Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.

[13] Triska. Dr. Hamlyn Encyclopaedia of Plants. Hamlyn 1975 ISBN 0-600-33545-3
Very interesting reading, giving some details of plant uses and quite a lot of folk-lore.

[14] Holtom. J. and Hylton. W. Complete Guide to Herbs. Rodale Press 1979 ISBN 0-87857-262-7
A good herbal.

[17] Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962
A very comprehensive flora, the standard reference book but it has no pictures.

[20] Riotte. L. Companion Planting for Successful Gardening. Garden Way, Vermont, USA. 1978 ISBN 0-88266-064-0
Fairly good.

[21] Lust. J. The Herb Book. Bantam books 1983 ISBN 0-553-23827-2
Lots of information tightly crammed into a fairly small book.

[55] Harris. B. C. Eat the Weeds. Pivot Health 1973
Interesting reading.

[57] Schery. R. W. Plants for Man. 0
Fairly readable but not very comprehensive. Deals with plants from around the world.

[61] Usher. G. A Dictionary of Plants Used by Man. Constable 1974 ISBN 0094579202
Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.

[62] Elias. T. and Dykeman. P. A Field Guide to N. American Edible Wild Plants. Van Nostrand Reinhold 1982 ISBN 0442222009
Very readable.

[100] Polunin. O. Flowers of Europe - A Field Guide. Oxford University Press 1969 ISBN 0192176218
An excellent and well illustrated pocket guide for those with very large pockets. Also gives some details on plant uses.

[106] Coon. N. The Dictionary of Useful Plants. Rodale Press 1975 ISBN 0-87857-090-x
Interesting reading but short on detail.

[115] Johnson. C. P. The Useful Plants of Great Britain. 0
Written about a hundred years ago, but still a very good guide to the useful plants of Britain.

[142] Brouk. B. Plants Consumed by Man. Academic Press 1975 ISBN 0-12-136450-x
Readable but not very comprehensive.

[147] ? A Barefoot Doctors Manual. Running Press 0 ISBN 0-914294-92-X
A very readable herbal from China, combining some modern methods with traditional chinese methods.

[165] Mills. S. Y. The Dictionary of Modern Herbalism. 0
An excellent small herbal.

[169] Buchanan. R. A Weavers Garden. 0
Covers all aspects of growing your own clothes, from fibre plants to dyes.

[177] Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984 ISBN 3874292169
An excellent book for the dedicated. A comprehensive listing of latin names with a brief list of edible parts.

[179] Reid. B. E. Famine Foods of the Chiu-Huang Pen-ts'ao. Taipei. Southern Materials Centre 1977
A translation of an ancient Chinese book on edible wild foods. Fascinating.

[183] Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990 ISBN 0-9628087-0-9
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.

[187] Phillips. R. & Rix. M. Perennials Volumes 1 and 2. Pan Books 1991 ISBN 0-330-30936-9
Photographs of over 3,000 species and cultivars of ornamental plants together with brief cultivation notes, details of habitat etc.

[192] Emboden. W. Narcotic Plants Studio Vista 1979 ISBN 0-289-70864-8
A lot of details about the history, chemistry and use of narcotic plants, including hallucinogens, stimulants, inebriants and hypnotics.

[200] Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992 ISBN 0-333-47494-5
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.

[201] Allardice.P. A - Z of Companion Planting. Cassell Publishers Ltd. 1993 ISBN 0-304-34324-2
A well produced and very readable book.

[213] Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980 ISBN 0-449-90589-6
A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.

[218] Duke. J. A. and Ayensu. E. S. Medicinal Plants of China Reference Publications, Inc. 1985 ISBN 0-917256-20-4
Details of over 1,200 medicinal plants of China and brief details of their uses. Often includes an analysis, or at least a list of constituents. Heavy going if you are not into the subject.

[238] Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995 ISBN 0-7513-020-31
A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.

[240] Chopra. R. N., Nayar. S. L. and Chopra. I. C. Glossary of Indian Medicinal Plants (Including the Supplement). Council of Scientific and Industrial Research, New Delhi. 1986
Very terse details of medicinal uses of plants with a wide range of references and details of research into the plants chemistry. Not for the casual reader.

[244] Phillips. R. & Foy. N. Herbs Pan Books Ltd. London. 1990 ISBN 0-330-30725-8
Deals with all types of herbs including medicinal, culinary, scented and dye plants. Excellent photographs with quite good information on each plant.

[245] Genders. R. Scented Flora of the World. Robert Hale. London. 1994 ISBN 0-7090-5440-8
An excellent, comprehensive book on scented plants giving a few other plant uses and brief cultivation details. There are no illustrations.

[254] Chevallier. A. The Encyclopedia of Medicinal Plants Dorling Kindersley. London 1996 ISBN 9-780751-303148
An excellent guide to over 500 of the more well known medicinal herbs from around the world.

[266] Flora of China 1994
On-line version of the Flora - an excellent resource giving basic info on habitat and some uses.

[272] Manandhar. N. P. Plants and People of Nepal Timber Press. Oregon. 2002 ISBN 0-88192-527-6
Excellent book, covering over 1,500 species of useful plants from Nepal together with information on the geography and peoples of Nepal. Good descriptions of the plants with terse notes on their uses.

[279] Medicinal Plants in the Republic of Korea World Health Organisation, Manila 1998 ISBN 92 9061 120 0
An excellent book with terse details about the medicinal uses of the plants with references to scientific trials. All plants are described, illustrated and brief details of habitats given.

Readers Comments

Acorus calamus

david Nicholls Mon Mar 5 10:14:17 2001

I tried using the root to quit smoking after also reading in "A modern Herbal" that it is used when Peruvian Bark fails, Peruvian bark containing quinine, the active ingredient in the best quit smoking aid (for me personally), Nicobrevin. Maybe many things for fever have potential as quit smoking aids.

I'm sure it did eliminate the desire for a smoke, didn't have one for 2 hours, one every 15 mins being my usual, had about 4mm-6mm sqaure of root , then also tried about the same of rhizome, taste the same(Potters say the rhiozme is often called the root so I tried both) same effect (obviously this is only vaugely scientific).

After finding I had to keep taking it every few hours I decided I was not prepared to take such large amounts for fear of hallucinations or other risks, maybe worth researhing, I hope & think no one could patent the idea with it's folk history, so pharmaceutical corporations probably wouldn't bother with it.

Note: I can't recommend it to anyone as safe.

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