Artemisia annua, also known as sweet wormwood, sweet annie, sweet sagewort, annual mugwort or annual wormwood (Chinese : 黄花蒿; pinyin : huánghuāhāo), is a common type of wormwood native to temperate Asia, but naturalized in many countries including scattered parts of North America.
An extract of Artemisia annua, called artemisinin (or artesunate), is a medication used to treat malaria. Discovery of artemisinin and its antimalarial properties by the Chinese scientist, Tu Youyou, led to award of the 2011 Lasker Prize and 2015 Nobel Prize in Physiology or Medicine.
Artemisia annua belongs to the plant family of Asteraceae and is an annual short-day plant. Its stem is erect brownish or violet brown. The plant itself is hairless and naturally grows from 30 to 100 cm tall, although in cultivation it is possible for plants to reach a height of 200 cm. The leaves of Artemisia annua have a length of 3–5 cm and are divided by deep cuts into two or three small leaflets. The intensive aromatic scent of the leaves is characteristic. The artemisinin content in dried leaves is in between 0% and 1.5%. New hybrids of Artemisia annua developed in Switzerland can reach a leaf artemisinin content of up to 2%. The small flowers have a diameter of 2–2.5 mm and are arranged in loose panicles. Their color is green-yellowish. The seeds are brown achenes with a diameter of only 0.6–0.8 mm. Their thousand-kernel weight (TKW) averages around 0.03 g (in comparison, wheat has a TKW of approximately 45 g).