Artemisia annua
| Artemisia annua | |
| Light: |   |
| Moisture: |   |
| Hardiness: | 7 |
| Soil pH: | 5.6-8.4 |
| Height: | 10' |
| Width: | 3' |
| Speed: | Fast |
| Blooms: | Late Summer-Early Fall |
| Native to: | |
| Edible Rating: |  |
| Medicinal Rating: |  |
| Tea: | Yes |
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Artemisia annua (common name: qing hao)
Propagation: Seed - sow spring in a cold frame and plant out in late spring or early summer. Alternatively, the seed can be sown late spring in situ.
Cultivation: An easily grown plant, succeeding in a well-drained circumneutral or slightly alkaline loamy soil, preferring a sunny position[1][2]. Plants are longer lived, more hardy and more aromatic when they are grown in a poor dry soil[3].
A fast-growing annual plant, it is tall but neat in habit with a handsome fragrant foliage and is useful for filling gaps at the back of a border[4]. It has become a weed of waste places in many areas of the world[5]. The plant is extremely vigorous and essentially disease and pest free[6].
Qing Hao is a determinate short-day plant. Non-juvenile plants are very responsive to photoperiodic stimulus and flower about two weeks after induction. The critical photoperiod seems to be about 13.5 hours, but there are likely to be photoperiod x temperature interactions. In Lafayette Indiana, USA (40°21'N) plants flower in early September with mature seeds produced in October. The plant is not adapted to the tropics because flowering will be induced when the plants are very small[6].
Most collections of artemisia derive from natural stands with highly variable artemisinin content, some as low of 0.01%. Selections from Chinese origin vary from 0.05 to 0.21%. Swiss researcher N. Delabays reports a clonal selection derived from Chinese material which produces 1.1% artemisin but is very late flowering; proprietary hybrids have been obtained with somewhat lower content but flower earlier[6].
Members of this genus are rarely if ever troubled by browsing deer[7].
Range: S. E. Europe to W. Asia.
Habitat: Occurs naturally as part of a steppe vegetation in the northern parts of Chahar and Suiyuan provinces in China, at 1000 to 1500 m above sea level[6].
Edibility: An essential oil in the leaves is used as a flavouring in spirits such as vermouth[6].
Medicinal: Qing Ho, better known in the West as sweet wormwood, is a traditional Chinese herbal medicine. An aromatic anti-bacterial plant, recent research has shown that it destroys malarial parasites, lowers fevers and checks bleeding[4][8][9]. It is often used in the Tropics as an affordable and effective anti-malarial[8].
The leaves are antiperiodic, antiseptic, digestive, febrifuge[10][11]. An infusion of the leaves is used internally to treat fevers, colds, diarrhoea etc[12][8]. Externally, the leaves are poulticed onto nose bleeds, boils and abscesses[12][4]. The leaves are harvested in the summer, before the plant comes into flower, and are dried for later use[8].
The plant contains artemisinin, this substance has proved to be a dramatically effective anti-malarial against multi-drug resistant Plasmodium spp[13][4][8][6]. Clinical trials have shown it to be 90% effective and more successful than standard drugs[8]. In a trial of 2000 patients, all were cured of the disease[13].
The seeds are used in the treatment of flatulence, indigestion and night sweats[12].
Usage: The plant is used in China as a medium for growing Aspergillus which is used in brewing wine.
The substances mentioned above in the medicinal uses, used in the treatment of malaria, also show marked herbicidal activity[12].
The plant yields 0.3% essential oil[14]. This has an agreeable, refreshing and slightly balsamic odour and has been used in perfumery[14].
Pollinators: Insects
Soil: Can grow in light and medium soils.
Drainage: Prefers well drained soil.
Seed Ripens: Early Fall-Mid Fall
Flower Type: Hermaphrodite
Known Hazards: Skin contact with the plant can cause dermatitis or other allergic reactions in some people[12].
The pollen is extremely allergenic[6].
Links
References
- ↑ Chittendon, Fred. RHS Dictionary of Plants. Oxford University Press, 1951.
- ↑ Huxley, Anthony. The New Royal Horticultural Society Dictionary of Gardening. MacMillan Press, 1992.
- ↑ Genders, Roy. Scented Flora of the World. Robert Hale, 1994.
- ↑ 4.0 4.1 4.2 4.3 Bown, Deni. Royal Horticultural Society Encyclopaedia of Herbs and Their Uses. Dorling Kindersley, 1995.
- ↑ Lyndon, Merritt. Gray's Manual of Botany. American Book Co, 1950.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Duke, James. Handbook of Energy Crops. 1983.
- ↑ Thomas, Graham. Perennial Garden Plants. J. M. Dent & Sons, 1990.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Chevallier, Andrew. The Encyclopedia of Medicinal Plants. Dorling Kindersley, 1996.
- ↑ Medicinal Plants in the Republic of Korea. World Health Organisation, 1998.
- ↑ Yeung, Him-Che. Handbook of Chinese Herbs and Formulas. Institute of Chinese Medicine, 1985.
- ↑ Stuart, George. Chinese Materia Medica. Taipei Southern Materials Centre.
- ↑ 12.0 12.1 12.2 12.3 12.4 Foster, Steven and Billy Tatum. Medicinal Plants of Eastern and Central North America. Houghton Mifflin, 1990.
- ↑ 13.0 13.1 Duke, James and Edward Ayensu. Medicinal Plants of China. Reference Publications, 1985.
- ↑ 14.0 14.1 Chopra, R. Glossary of Indian Medicinal Plants. Council of Scientific and Industrial Research, New Delhi, 1986.