Many plants in the genus Artemisia are known as “wormwood,” although most people use the term specifically to refer to A. absinthium or grande wormwood, the primary active ingredient in absinthe. This variety has been used medicinally in a variety of ways for centuries, and despite concerns about its health risks, few studies have really examined the plant and its compounds closely.
Wormwood is native to Europe, although it has since spread to Asia, Africa, and North America. It grows primarily in temperate zones, and readily takes over when given a chance to do so. People can recognize the plant by its shrub-like look, tall gray-green hairy stems, and lobed yellow green leaves, which are typically arranged in a spiral pattern around the stems. It also has a very distinctive sharp, spicy odor that some people describe as bitter or acrid.
The plant prefers full sun, and it likes to grow in dry soil. Wormwood often grows very well in poor soil, taking over where other plants cannot grow, although it prefers medium-weight soil which is high in nitrogen. In temperate zones, the plant will grow as a perennial, while in colder zones, it may die off during the winter, due to frost. Its bitter flavor and odor, incidentally, makes it an excellent method of natural pest control.
A number of cultures have used wormwood in various medical applications. The plant has historically been used in tisanes and tinctures for things like labor pains, digestive problems, and cardiac issues. Wormwood's effectiveness as a treatment for these conditions has not been proved, and because compounds in the plant can potentially be toxic, these treatments should only be undertaken with caution, with the products prepared by skilled herbalist. Pure extract should never be consumed.
The main toxin of concern in wormwood is thujone, the same compound that allegedly makes absinthe a hallucinogen. In fact, thujone does not appear to have hallucinogenic properties, but in large amounts, it can cause damage to the nervous system, resulting in convulsions, loss of muscle control, and sometimes death, if enough is involved. The amount of thujone in absinthe is typically quite minimal, as wormwood is only one of an assortment of herbs macerated in alcohol to yield this spirit.