:Non-edible Other Uses
Scientific Name: Acorus calamus L.
Also known as: Sweet flag, sweet sedge, sweet root, sweet cane, gladdon, sweet myrtle, myrtle grass, myrtle sedge, cinnamon sedge.
Habitat: Calamus grows at the edges of ponds, rivers and small lakes, and in marches, swamps, and wetlands in central Asia, India, Siberia, southern Russia where it originates. It is also found in eastern Europe, China and Japan, and was introduced to Europe and North America as a medicine, where it has since been naturalised.
Description: Calamus is a rather elegant herbaceous perennial, growing 30-100cm tall with long, tapering, sword-shaped pointy leaves, flat and narrow with smooth edges that can be wavy or crimped. Calamus has an aromatic, pungent, bitter taste and a sweet aromatic smell.
You can distinguish it from the iris and other similar plants by the wavy, crimped leaf edges and a sweet scent when they are crushed, and by the easily recognisable, semi-erect spadix arising from the axils of the outer leaves.
The flowers appear for about a month in spring or early summer and are sweetly fragrant. Calamus does not always bear fruit but mainly propagates itself by its rhizome spreading and forming colonies.
- Leaves – 30 to 100cm tall, its leaves resembles those of the iris family. Sweet flag consists of tufts of basal leaves that rise from a spreading rhizome. The leaves are erect yellowish-brown, radical, with pink sheathing at their bases, sword-shaped, flat and narrow, tapering into a long, acute point, and have parallel veins. The leaves have smooth edges, which can be wavy or crimped.
- Flower stem – The solid, triangular flower-stems rise from the axils of the outer leaves. A semi-erect spadix emerges from one side of the flower stem.
- Flowers – The spadix is solid, cylindrical, tapers at each end, and is 5 to 10 cm in length. A covering spathe, as is usual with Araceae, is absent. The spadix is densely crowded with tiny greenish-yellow flowers. Each flower contains six petals and stamens enclosed in a perianth with six divisions, surrounding a three-celled, oblong ovary with a sessile stigma. The flowers are sweetly fragrant. In Europe, it flowers for about a month in late spring or early summer, but does not bear fruit.
- Fruit – The fruit is a berry filled with mucus, which when ripe falls into the water and disperses by floating. In Asia, it also fruits sparingly, and propagates itself mainly by growth of its rhizome, forming colonies.
- Rhizome – The rhizome is finger-thick, branched and knobby, brown on the outside, white and porous inside with scattered vascular bundles, and with numerous, coarse, fibrous roots underneath.
Pictures throughout the year
The rhizome is candied and made into a sweetmeat. It can be peeled and washed to remove the bitterness and then eaten raw like a fruit. It makes a palatable vegetable when roasted and can also be used as a flavouring. Rich in starch, the root contains about 1% of an essential oil that is used as a food flavouring. The root also contains a bitter glycoside. Some caution is advised, see the notes on toxicity. The dried and powdered rhizome has a spicy flavour and is used as a substitute for ginger, cinnamon and nutmeg. A pinch of the powdered rhizome is used as a flovouring in tea. The young and tender inflorescence is often eaten by children for its sweetness. Young leaves – cooked. The fresh leaves contain 0.078% oxalic acid. The leaves can be used to flavour custards in the same way as vanilla pods. The inner portion of young stems is eaten raw. It makes a very palatable salad
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. In Ayurveda it is highly valued as a rejuvenator for the brain and nervous system and as a remedy for digestive disorders. 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. It is used internally in the treatment of digestive complaints, bronchitis, sinusitis etc. 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 and it is, therefore, recommended in the treatment of anorexia nervosa. However if the dose is too large it will cause nausea and vomiting. Sweet flag is also used externally to treat skin eruptions, rheumatic pains and neuralgia. An infusion of the root can bring about an abortion whilst chewing the root alleviates toothache. It is a folk remedy for arthritis, cancer, convulsions, diarrhoea, dyspepsia, epilepsy etc. Chewing the root is said to kill the taste for tobacco. Roots 2 – 3 years old are used since older roots tend to become tough and hollow. They are harvested in late autumn or early spring and are dried for later use. The dry root loses 70% of its weight, but has an improved smell and taste. It does, however, deteriorate if stored for too long. 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. See also the notes on toxicity. A homeopathic remedy is made from the roots. It is used in the treatment of flatulence, dyspepsia, anorexia and disorders of the gall bladder. Bath oils containing calamus have caused redness of the skin (erythema) and dermatitis, particularly in hypersensitive individuals.
- Aromatic bitter
- Spasmolytic and abdominal antispasmodic
The effect of calamus is a combination of its demulcent, carminative and stimulating
properties. It shares the property of being carminative and tonic with Angelica archangelica
but smells and tastes a little more pungent, and is an excellent tonic for the whole digestive
Calamus is mainly used for atonic dyspepsia, wind, colic, hyperacidity and gastric ulcer. It
has a powerful tonic effect on the stomach, stimulating secretions, and also stimulating
appetite. Calamus tea is beneficial before meals for people who have lost their appetite,
including stomach cancer, anorexia nervosa, and for stomach cramps and colic.
Calamus has a long reputation as a warming, healing herb for the stomach and digestion
because it stimulates production of digestive juices, starting with saliva, and helping to
counter acidity and reduce heartburn and dyspepsia, while also relaxing peristalsis and
reducing catarrh of the intestinal mucosa.
Used in Chinese medicine for rheumatoid arthritis.
Externally, the oil can be used as a refreshing ointment of tired feet or varicose veins.
Chewing calamus root has a tonic effect on the mucous membranes of the mouth and
throat while also stimulating salivation. Tied up in a piece of linen, it can help soothe
teething children. Orris root can be used for the same purpose.
Folklore and traditional use
In traditional Chinese medicine, calamus is used to treat deafness, dizziness and epilepsy.
Calamus is a symbol of love and is associated with the Greek myth about Kalamos, son of
the river-god, who loved Karpos, son of the west wind and the spring. When Karpos
drowned, Kalamos also drowned and was transformed into a reed, whose rustling in the
wind was interpreted as a passionate lamenting sigh.
Calamus root (rhizome) has been used medicinally for thousands of years in Chinese and
Indian herbal medicine. It is used in the holy anointing oil mentioned in the Bible, and in
ancient Egyptian texts as part of bandages, in soothing stomach remedies, and to make
perfume. It is also mentioned in early Persian texts and is thought to be the ‘calamus’ or
sweet cane of Palestine.
It was introduced to Britain in the late 16th century, and listed by Gerard among the plants
he grew in his garden. and the essential oil is used to make perfume and to flavour pipe
tobacco. It is also eaten crystallised (German ginger), in bread (Lithuanian Ajeras) and
added to wine, bitters and liqueurs.
Historic records show the use of calamus for the plague and for rabies.
Calamus appeared in the British Pharmacopoeia until 1935.
Calamus is a strong, and effective, remedy with focus on the stomach, and specifically for
flatulent colic. It should be used carefully, for specific purposes, and not for long periods of
time. It is an excellent tonic, giving power to a weak system. The oil is used externally but
should not be used internally.
- Powdered root: 1-3g TDS
- Liquid extract: 1:1 in 60% alcohol. 1-3ml (15-45 drops) TDS
- Tincture: 1:5 in 60% alcohol. 2-4ml TDS .
- Juice: Fresh rhizome juiced and taken in teaspoon doses. TDS
- Infusion: 2 tsp dried root to 200ml of boiling water.
- Cover and infuse for 10-15 mins.
- Drink 1 cup half an hour before meals
- Cold infusion: (Maria Treben’s cure for stomach cancer)
- 1 tsp crushed root to 1 cup of cold water. Infuse (cold) overnight.
- Strain and drink 1 sip before and after meals. Max 1 cup per day.
Regulatory status: GSL
The essential oil is not use because of the FDA ruling in 1968.
- With ginger and wild yam for flatulent colic.
- With meadowsweet and marshmallow for gastric conditions.
The leaves are used in basket making or woven into mats. They have also been used as a thatch for roofs. An essential oil from the rhizome is used in perfumery and as a food flavouring. The oil is contained mainly in the outer skin of the root, it has a fragrance reminiscent of patchouli oil. The fresh roots yield about 1.5 – 3.5% essential oil, dried roots about 0.8%. Some plants from Japan have yielded 5% essential oil. The essential oil is also an insect repellent and insecticide. It is effective against houseflies. 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. An essential oil obtained from the leaves is used in perfumery and for making aromatic vinegars. The leaves and the root have a refreshing scent of cinnamon. All parts of plant can be dried and used to repel insects or to scent linen cupboards. They can also be burnt as an incense, whilst the whole plant was formerly used as a strewing herb. The growing plant is said to repel mosquitoes
Caution is advised on the use of calamus root, especially the essential oil, and large doses
can cause mild hallucinations.
Bath oils containing calamus have caused erythema and dermatitis in hypersensitive
The essential oil contains arasone. Products derived from Acorus calamus were banned
from use as human food and food additives by the US Food and Drug Administration (FDA)
in 1968 on the basis of animal experiments involving massive doses of isolated chemicals
(beta-asarone) from the Indian Jammu strain of calamus. On the strength of these
experiments, calamus was labelled procarcinogenic, although there is no evidence or
observation of calamus having a similar effect on humans. In reality, beta-asarone is neither
hepatotoxic nor directly carcinogenic without being hydrolised.
It should also be noted that calamus has been widely used since antiquity, and there have
been no reports of cancer developing after it was taken. It is important not to rely on animal
While there is clearly no risk in using appropriate doses for limited periods of time, large
doses can irritate the digestive tract, and there are reports of prolonged vomiting in people
who take large quantities for its reputed hallucinogenic effects.
Calamus has been cultivated for medicinal purposes for a very long time. It has been
allowed to become naturalized and then harvested from the wild. It can spread quite
quickly and soon becomes established.
Harvest in the autumn. Free the rhizome from roots and leaves, rinse it well, halve
lengthwise and dry in the shade or in a dehydrator.
Other sedges and flags, such as Yellow Flag, for example.
- Wikipedia – https://en.wikipedia.org/wiki/Acorus_calamus
- PFAF – https://pfaf.org/user/plant.aspx?latinname=Acorus+calamus
- Heartwood – Professional Herbalist Course