Last updated: 19th November 2002


WORMWOODS, MUGWORTS


Family: Compositae

Genus: Artemisia

Species: various (listed below)

A. vulgaris
Source: http://www.c-potenz.de/Mittel/Artemisia-vulg.html

Contents

General Background
Details of Quality Characteristics
Current Production and Yields
Constraints upon Production
Markets and Market Potential
Other Information
Research
Useful Websites
BioMat Net
Contacts
References

General Background

The genus Artemisia spp, includes the herb Tarragon. The plants are herbaceous or suffruticose (woody in the lower part of the stem, but with yearly branches herbaceous) perennials and are rarely shrubs or annual herbs. They posses alternate pinnasect or palmatisect leaves. Racemes or racemose panicles bear numerous small flowerheads. The plants range in height depending on the species, from 30 - 120 cm high.

Artemisia vulgaris (Mugwort):
A. vulgaris seems to have originated in Eastern Europe and Western Asia. Most of these species are found growing wild and abundantly all over the temperate and cold temperate zones of the world. It is a very common weed in Central Europe, Southeastern Europe, India, China and Japan. This perennial aromatic herb, 60 - 120cm high, has a branching root stock, dark green deeply indented leaves with reddish, grooved and angled, glabrescent or sparsely pubescent stems. The plant's florets are wind pollinated.

Artemisia annua (Sweet Wormwood):
This species is an erect glabrous annual growing up to 150 cm. The stems are often red. The upper leaves are 1-2 x pinnatisect; the middle and lower leaves are 3 x pinnatisect. The capitula are hemispherical, up to 4 mm in diameter and occur in loose spreading panicles. The plant flowers in the summer-autumn and produces yellow florets.

Artemisia abrotanum (Southernwood):
A perennial native to southern Europe. This is more compact and woody than most Artemisia spp. It is strongly aromatic with a bitter lemony scent. The foliage is dense with finely divided grey-green segments. Flowers are yellow, small and in loose panicles.

Artemisia absinthium (Wormwood):
This is a perennial aromatic plant. It has erect angled, grooved stems 30-90 cm high which are covered in silky hairs. The heads are 3-4 mm in diameter and occur in loose spreading panicles.

Artemisia arborescens:
This is a glabrous aromatic perennial growing to 100 cm in height. The stems are woody at the base and the leaves are 1-2 x pinnatisect. Capitula are up to 7mm in diameter and are hemispheric and occur in large panicles. In the autumn the florets are yellow/brown. The plant grows well in Mediterranean climates. The variety 'Faith Raven' grows to 100 cm and is a hardy evergreen with silver leaves. 'Powis Castle' which has silvery filigree leaves is associated but unlikely to have been directly derived from A. arborescens.

Artemisia campestris (Field Southernwood):
Perennial, scentless plant with a branched creeping woody stock. Produces tufts of non-flowering shoots. The flowering shoots are 20 - 60 cm high, woody below. The heads are 3-4 mm in diameter and flowers are reddish or yellow. The marginal flowers are female and the central ones can be hermaphrodite but are mainly sterile.

Artemisia douglasiana:
A perennial plant growing to 300cm tall with herbaceous stems, sometimes branched. The leaves are 5 - 15 cm elliptic. The capitula occur in open or dense elongated panicles.

Artemisia maritima (Sea Wormwood):
Perennial, strongly aromatic. Short usually branching vertical woody stock, non-flowing rosettes, with erect flowering shoots of 20 -50 cm high. The heads are 1 -2 mm in diameter.

Artemisia pontica (Roman Wormwood):
An aromatic rhizomatous perennial growing to 80cm high. The leaves are finely cut, 1-2 pinnatisect. The capitula are 6mm in diameter. The flowers are fragrant and yellow/grey in colour.

Artemisia stellerana (A. ludoviciana, Old Woman, Dusty Miller, Beach Sagewort):
Perennial, non-aromatic. Possess a creeping woody stock and densely white felted stems, 30 -60 cm high. The flower heads are 5-9 mm in diameter. Marginal flowers are female and the central flowers are hermaphrodite, all flowers are yellow. Grown mainly as an ornamental for its white foliage.

Artemisia verlotiorum (Verlots Mugwort):
This perennial herb resembles A. vulgaris but is more strongly aromatic and pleasantly scented.

Details of Quality Characteristics

Artemisia vulgaris. (Mugwort):
The organoleptic and physio-chemical properties are as follows:

Organoleptic properties
Appearance: Fluid liquid
Colour: Pale yellow or slightly greenish
Aroma: Powerful, fresh-camphoraceous, somewhat green and bitter sweet.

Physico-chemical properties
Specific gravity: 0.8786 to 0.9265 at 25°C
Optical rotation: [-] 13.25° to [-] 29.35° at 25°C
Refractive index: 1.350 to 1.49 at 25°C
Acid number: 2.49 to 6.5
Ester number: 25.05 to 55
Ester number after acetylation: 65 to 90
Solubility: Insoluble in alcohol

Artemisia annua:
The main active principal, artemisinin (formally referred to as arteannuin and as qinghaosu in Chinese), was found to be a sequiterpene lactone with a endoperoxide bridge (J. F. S. Ferreira and J. Janick. 1996). Artemisinin also has phytotoxic activity, even on A. annua, and is a candidate as a natural herbicide (Duke et al. 1987, Chen et al. 1991).

Artemisinin production by A. annua is usually in the range of 0.01% to 0.4% but some clones produce over 1%. Artemisinin can also be obtained from artemisinic acid which occurs in concentrations as much as 10-fold higher than artemisinin. Vonwiller et al. (1993) reported an extraction method which makes possible the extraction of both compounds from the same plant material, thus increasing the final production of artemisinin. In vitro studies indicate that the biosynthesis of artemisinin is enhanced by the presence of roots. Artemisia annua is unlikely to be produced economically by chemical synthesis or by in vitro production, thus A. annua is a potential new antimalarial crop for temperate areas.

Artemisia abrotanum (Southernwood):
Contains a volatile oil, abrotanin and tannins which are collected from the aerial parts in late summer. Infusions make a bitter tonic which strengthens and supports digestive functions by increasing secretions in the stomach and intestines. Like other Artemisias, southernwood stimulates menstruation and should be avoided during pregnancy. It also contains a strong volatile oil which repels insects. Southernwood is now used infrequently as wormwood is considered to be superior.

Artemisia absinthium (Wormwood):
Leaves are used for flavouring and are harmless, but in the concentrated form Wormwood is a powerful addictive poison producing stimulant and euphoric effects similar to those of alcohol infused with absinthe, and ultimately resulting in severe brain damage. Absinthe as an alcoholic drink was banned in France in 1915.

Allelopathy has been demonstrated in A. absinthium. Volatile emanations from its leaves completely prevented germination in wheat, and inhibited seedling growth in wheat, hoary cress and common flax, whereas seedling growth on white mustard was markedly stimulated.

Extracts made of leaves of A. absinthium prevent germination on all the above species, and extracts of roots prevented germination of wheat and reduced root and shoot elongation in hoary cress, common flax and white mustard by 53 - 85% (Nancy Eckardt 1987).

An aqueous/methanolic extract has been shown to exhibit hepatoprotective action partly through MDME inhibitory action, which validates the traditional use of the plant in hepatic damage.

Artemisia arborescens:
A new sequiterpene lactone 3a,4a-10b-trihydroxy-8a-acetyloxyguaian-12,6a-olide, has been isolated from aerial parts of this plant. The Greeks and the Arabs applied this vaginally for contraceptive purposes (Grandolini 1988). This compound forms white prisms from ethanolic solution, and has a m.p. of 140-145°C.

3a,4a-10b-trihydroxy-8a-acetyloxyguaian-12,6a-olide

Artemisia cina (Levant wormwood) and A. maritima (Sea wormwood):
Produce an anthelmintic, santonin known as santonica (A. cinc) or vermifuge (A. maritima) (D. J. Mabberley 1987). Unopened flowerheads are used.

Artemisia herba alba and Artemisia pallens:
Have been widely used in Iraqi and Indian (respectively) folk medicine for the treatment of diabetes mellitus. Oral administration of an aqueous/methanolic extract from the aerial parts of the plants led to significant blood glucose lowering effect in glucose-fed hyperglycemic and alloxan-induced diabetic rabbits and rats (Twaij HA and Al-Badr AA, 1988 and Subramoniam A et al 1996)

Artemisia pontica (Roman Wormwood):
This is used to produce the flavour of vermouth.

Artemisia tilesii:
This plant produces a substance with properties like codeine (D. J. Mabberley,. 1987).

Current Production and Yields

EU-15 countries currently showing an interest in Artemisia are Austria, Finland, France, Italy Sweden and the UK. Of these France and Sweden are currently running pilot studies on Artemisia.

Oil yields - world market tonnage

Plant World market Tonnage Available oil yield kg/ha
Artemisia (Wormwood) 7 25
Tarragon 10 12


Planted area of medicinal, aromatic and perfume plants in mainland France 1995

Area (ha) Crop species
> 100 - < 1,000 Tarragon
> 10 - < 100 Wormwood
< 10 Artemisia

Source IENICA Summary report for the European Union 2000

In France, Artemisia spp is grown as a medicinal, aromatic and perfume plant.

Fresh weight and oil yield of Artemisia annua in response to plant spacing and nitrogen application (average yields from 1985 and 1986)

N (kg/ha)
0 67 134
Density ('000 plants/ha) Biomass yield (t/ha)
27.7 21 23 24
55.5 23 30 28
111 30 35 33
Essential oil yield
(kg oil/ha)
27.7 56 61 56
55.5 67 85 69
111 78 78 83

Source: Simon et al (1990)

Constraints upon Production

Southernwood is native to western Asia and has naturalised in Spain, Italy and other Mediterranean countries. It will not set seed and rarely flowers in the UK or in northern Europe. In southern Europe it is rare in the wild, but is cultivated for the perfume industry.

The plant is extremely aggressive and invasive and will inhibit the growth of nearby plants by the means of root secretions. The plant is spread both by seeds and vegetation; dispersal occurs in most cases by seeds coming from plants in hedges. The severity of mugwort as a weed causes problems in some farming systems as it is so difficult to eradicate once established. The occurrence of volunteers is becoming an increasing worry in such farming systems.

Markets and Market Potential

The leaves and roots of the plant provide a digestive and tonic herb which has a wide variety of traditional uses. It can be taken over the long term at a low dose to improve appetite, digestive function and absorption of nutrients. It can also be taken to eliminate worms. A. vulgaris has traditionally been taken to aid childbirth and its after effects. Mugwort contains a volatile oil, a sequiterpene lactone, flavonoids, coumarin derivatives and triterpenes. Sesquiterpene lactones have many properties which include: Bitter tasting, antibiotic, anthelmintic, anti-inflammatory and phytotoxic. The cytotoxic activities have also been extensively researched (D. Frohne and J. Pfänder, 1984).

An essential oil known as Artemisia oil or Armoise oil is obtained by steam distillation of the aerial part of Artemisia vulgaris and is used in perfumes and as a flavouring agent.

A. annua was mentioned in the 'Chinese Handbook of Prescriptions for Emergency Treatments' of 340 AD as a treatment for fevers. In 1971 extraction of aerial parts of A. annua with low boiling solvents produced a compound mixture with anti-malarial properties on infected mice and monkeys. Artemisinin is now commercially available in China and Vietnam as an anti-malarial drug effective against drug-resistant strains of Plasmodium, the malarial parasite.

A. absinthium is used in the production of the essential oil absinthe used in alcoholic drinks. Wormwood was traditionally used all over Europe as a vermifuge (hence the name) and to cure various gastric disorders.

Artemisia aborescens could be improved to be grown commercially for the production of artemisan, a natural contraceptive (Unreferenced communication from MAFF (now DEFRA) via Melvyn Askew, CSL, Sand Hutton, York, YO41 1LZ).

Artemisia herba alba and Artemisia pallens have been widely used in Iraqi and Indian folk medicine as a treatment for diabetes mellitus.

Other Information

The various species of Artemisia grow in a range of conditions around Europe. Artemisia vulgaris is found in temperate regions of the northern hemisphere. It flourishes on waste ground and in hedgerows. It is best suited to well-drained neutral or slightly alkaline loamy soils, preferring a sunny yet moist position. Plants are generally longer lived, more hardy and more aromatic when grown in a poor dry soil. A wide range of pH can be tolerated depending on the species but it is generally between 4.8-8.2, once established the plants are drought tolerant. The crop is gathered in late summer just before flowering.

Wormwood is said to inhibit growth of fennel, sage, caraway, anise and most young plants - particularly in wet years. Generally Artemisia is thought to deter insects from other plants growing nearby.

Levant wormwood is native to the region stretching from the Eastern Mediterranean to Siberia. The unopened flowers are gathered from wild and cultivated plants.

In some areas A. absinthium can become a weed problem especially where it can become established on disturbed areas where there is little competition from other plants (N Eckardt.1987). A. annua is extremely vigorous and essentially disease and pest free.

Research


Useful Websites

http://www.hort.purdue.edu - General information and research papers relating to Artemisia

BioMat Net

FAIR3-CT96-1781
Terpenes as natural chiral starting materials for the synthesis of flavours, fragrances, pharmaceuticals and biocontrol agents.

FAIR-CT96-2003
Volume extraction and encapsulation of flavour chemicals, pharmaceutical substances, bio-chemicals and enzymatic systems.

FAIR-CT97-3628
Improving production and quality of essential oil from aromatic plants by genetic engineering

Contacts


References