Wormwood is a perennial plant in the aster family with a natural range that includes parts of Europe, Africa and Asia, as well as eastern North America. The prolific spread of the herb is due to its self-seeding habit and its ability to thrive in rocky, uncultivated soil.
Although the plant is considered toxic, wormwood has a long history of use as a bitter flavoring agent for various beverages. It was commonly used to make English mead and, until hops came into the picture in the 19th century, it was used in beer-making. Today, it is still used to flavor absinthe and vermouth. Wormwood is also an ingredient in herbal bitters.