ARTEMISIA ANNUA: CHARACTERISTICS, HABITAT, PROPERTIES, CARE - BIOLOGY - 2025

Artemisia annua is a species of aromatic herbaceous plant that belongs to the Asteraceae family. Commonly known as sweet wormwood, Chinese wormwood, or annual mugwort, it is a plant native to eastern China.

It is a fast growing annual plant with a single herbaceous stem that reaches up to 2 m in height. The green pinnatisect and tripinnatisect leaves are very aromatic, the greenish-yellow flowers are grouped in terminal spikes.

Artemisia annua. Source: Raffi Kojian

Its natural habitat is located on rocky areas and wastelands on the fringes of wooded areas and semi-desert slopes at an altitude of 2,000-3,500 meters above sea level. It develops effectively at full sun exposure, on clay soils and with an adequate supply of organic matter, although it grows on poor soils its growth is lower.

Since ancient times it has been considered a medicinal plant used to lower fever and more specifically malaria. "Artemisinin" is the active component extracted from stems, leaves and flowers, its concentration being higher in new shoots.

At present, the Artemisia annua species is considered an alternative against malaria in cases of resistance to other drugs. The WHO recommends combination therapies with artemisinin for the control of Plasmodium falciparum in areas where it is considered endemic.

General characteristics

Flowers of Artemisia annua. Source: Kristian Peters - Fabelfroh 11:40, 16 September 2007 (UTC)

Appearance

Artemisia annua is an annual herbaceous species that reaches between 30-250 cm in height, with a tower-shaped foliar architecture. It is formed by a cylindrical green stem and erect bearing, 20-60 mm thick and few branches between 30-80 cm in length.

Leaves

The bi-pinnatifid leaves with serrated margins and linear segments are covered by dense glandular trichomes on both sides and are 2.5-5 cm long. The lower ones are alternate, ovate and triangular; petiolate and pinatisect stockings; the upper ones pinatipartidas. All with glandular trichomes that give off a camphorated essence.

flowers

The flowers of 2-3 mm in diameter, intense yellow color and covered by numerous bracts, are grouped in inflorescences forming terminal panicles. The central flowers are hermaphrodite with five lobed corollas and five stamens, the external female with four lobed corollas, contain glandular trichomes.

Fruit

The fruit is an ovoid achene or dried fruit 0.5-0.8 mm in diameter with grayish tones. Tiny, light brown spherical seeds are found inside.

Chemical composition

The annual chemical analysis of mugwort has made it possible to determine the presence of volatile and non-volatile phytochemicals. Among the volatile essential oils, the non-volatile ones include coumarins, flavonoids and sesquiterpenes.

Sesquiterpenes include the active principles artemisinic acid and artemisinin, a sesquiterpene lactone recognized for its antimalarial activity. Other compounds related to artemisinin are coumarins, aliphatic, aromatic and phenolic compounds, flavonoids and lipids, which increase the antimalarial effect of this species.

Taxonomy

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Magnoliopsida

- Order: Asterales

- Family: Asteraceae

- Subfamily: Asteroideae

- Tribe: Anthemideae

- Subtribe: Artemisiinae

- Genus: Artemisia

- Species: Artemisia annua L.

Etymology

- Artemisia: the name of the genus comes from the Greek name of the goddess Diana «Artρτεμις» which translates as Artemis. In the same way she is related to Artemis II of Caria «Artρicingיισίισίי», governor of the ancient Medean and Persian empires, an expert in medicine and botany.

- annua: the specific adjective derives from the Latin "annual", referring to the annual vegetative cycle of the plant.

Synonymy

- Artemisia annua f. macrocephala Pamp.

- Artemisia chamomilla C. Winkl.

- A. exilis Fisch. ex DC.

- A. hyrcana Spreng.

- Artemisia plumosa Fisch. ex Bess.

- Artemisia stewartii CB Cl.

- A. suaveolens Fisch.

- A. wadei Edgew.

Leaves of Artemisia annua. Source: Raffi Kojian

Habitat and distribution

The A rtemisia annua species is a herbaceous plant native to the Hunan province in China. At present it is widely distributed in central and southern Europe, it is also naturalized in North America.

Its natural habitat is located in ruderales, rocky areas, intervened land or fallow land, on the edge of roads, highways, railway cliffs or landfills. It grows on soils of calcareous or siliceous origin, with medium fertility and neutral pH, at lower elevational levels between 2,000 and 3,500 meters above sea level. It is a synanthropic plant.

Properties

Artemisia annua is a species known since ancient times for its many healing properties with anthelmintic, spasmolytic and deworming effects. In its place of origin it is recognized as an effective natural remedy for the treatment of hemorrhoids and its curative action against malaria.

Recently, medical studies funded by the Chinese government have confirmed the high antimalarial potential of Artemisia annua. It was possible to identify the active principle artemisinin, which constitutes an alternative with antiplasmodic action to antibiotics and quinine.

In its wild state, Artemisia annua contains a maximum of 0.5% artemisinin. However, experimental genetic tests have allowed increasing its content to 1.1-1.4% which, combined with an abundant biomass, constitutes an alternative of sanitary and economic value.

On the other hand, the natural use of this species has made it possible to identify certain chemical compounds with antioxidant action against cancer or antibiotics against dermatitis. Review that the annual mugwort is used as an antibacterial to cure bacterial diseases on the skin.

In addition, its antiseptic effect is known to prevent and delay the development of microbes. It also has a digestive and carminative effect, since it regulates the expulsion of intestinal gases; likewise, it acts as a febrifuge reducing body temperature.

Seeds of Artemisia annua. Source: Steve Hurst

How to use

In traditional medicine it is used as an infusion or the properties of the dried leaves are used.

- Infusion: two tablespoons of flowers are placed in a liter of boiled water and left to rest. This infusion is used to lower fever, cure colds, relieve stomach and liver disorders, and heal ulcers.

- Dry leaves: several leaves inside a fabric cushion near the pillow allow you to fall asleep. One or two sheets on the shoes refresh the feet and relieve fatigue.

- Branches: a bunch of dried leaves hanging in the kitchen, barn or home gardens allows to ward off pests and flies.

- Nectar: ​​the essential oils extracted from the leaves are used to flavor food, poles, sweets or alcoholic beverages.

Care

Requirements

The cultivation of annual mugwort requires loamy soils exposed to full sun exposure, it even adapts to soils with a clay texture. It is a plant that is undemanding to the nutritional content of the soil, although it requires moist, but well-drained soil.

In general, its annual vegetative cycle begins during spring and summer, and flowering occurs at the end of summer. Under wild conditions it is moderately tolerant to low temperatures, however, it tends to dry out completely when frosts begin.

The photoperiod is a factor that influences the productive quality of this crop. Photoperiods shorter than 12 light hours reduce the vegetative cycle and induce flowering, which limits its cultivation in tropical regions.

Seedling of Artemisia annua. Source: Ton Rulkens

Culture

The cultivation of the annual mugwort is done by means of seeds. The plantation is established in seedbeds under greenhouse conditions, using a universal substrate and maintaining constant humidity and temperature conditions.

When the seedlings reach a height of 10 cm or 2-4 true leaves, they will be ready to be transplanted into the open ground. The recommended optimum density for commercial crops is 6 plants per square meter.

The application of organic fertilizers or chemical fertilizers rich in phosphorus and potassium contribute to the increase in the foliage of the crop. Likewise, frequent watering favors the productivity of the plant, as well as the control of weeds from the growth phase.

The annual mugwort grows best in rich soils in the open field, it prefers humid soils so it requires frequent watering. Newly transplanted seedlings and potted crops require less frequent watering due to the tighter root system.

Harvest

The harvest is determined by the artemisinin content that the plant may contain at the time of harvest. The highest content of this sesquiterpene in the plant tissues coincides with the start of flowering, being the time for harvest.

The harvest consists of collecting the leaves and apical branches of the plant, to dry in a shady and ventilated place. It is advisable to leave the semi-woody part of the stem in the field to regrow after a few days.

Cultivation of Artemisia annua. Source: Jorge Ferreira

Plagues and diseases

There are few reports of pests or diseases of economic importance obtained in the cultivation of Artemisia annua. In the United States, the only pest reported is lepidopteran larvae, although without causing significant damage to the plant.

Experimental cultures carried out in Tasmania (Australia) using a high planting density, the appearance of the disease known as Sclerotinia was observed. The high relative humidity of the environment favors the development of the fungus Sclerotinia sclerotiorum, the causal agent of necrosis of the basal part of the stem.

The presence of aphids in the buds or shoots of the crop promotes the appearance of certain viruses in the plant. The main symptoms are shrunken and malformed leaves, the best control method is to eliminate diseased plants and perform crop rotation every two years.

References

1. Acosta de la Luz, L., & Castro Armas, R. (2010). Cultivation, harvest and postharvest processing of Artemisia annua L. Revista Cubana de Plantas Medicinales, 15 (2), 75-95.
2. Chinese Wormwood - Sweet Wormwood - Artemisa Annua (2019) For My Garden. Recovered in: paramijardin.com
3. Artemisia annua (2019) Wikipedia, The Free Encyclopedia. Recovered at: wikipedia.org
4. Artemisia annua L. (2019) Catalog of Life: 2019 Annual Checklist. Recovered at: catalogueoflife.org
5. Bissanti, Guido (2019) Artemisia annua. An Eco-sustainable World. Recovered in: antropocene.it
6. Cafferata, LF & Jeandupeux, R. (2007). Solvent extraction of artemisinin and other metabolites from Artemisia annua L. wild. SeDiCi. Diffusion Service of Intellectual Creation. 108 pp.
7. Guerrero, L. (2002). Artemisia Annua: new perspectives in the treatment of Malaria. Natura Medicatrix: Medical Journal for the Study and Dissemination of Alternative Medicines, 20 (4), 180-184.