Mugwort

🇺🇸 History in the United States

Mugwort is a Eurasian herb with a long Old World reputation in medicine, brewing, and folklore, and it reached North America very early in the colonial era. Seed may have been brought as early as the 16th century by Jesuit missionaries in Canada, and European colonists in the 1600s carried the herb deliberately for ointments and teas while also introducing it accidentally in the soil ballast that sailing ships dumped at Atlantic port cities. Through the 18th and 19th centuries it continued to arrive repeatedly as a contaminant of ship ballast and later of imported nursery stock, which seeded persistent colonies around eastern seaports. From these beachheads it spread along railways, roadsides, and river corridors, becoming a fixture of urban and industrial waste ground in the Northeast. It is now documented in at least 34 states and every Canadian province and is formally classified as an invasive plant in states such as New York and Connecticut. As allergy science matured in the 20th century, mugwort was recognized as one of the most clinically important weed pollens of the Artemisia genus — in Europe it affects an estimated 10-14% of pollen-allergic patients — and it contributes to late-summer hay fever in the American Northeast, while related native sagebrushes dominate Artemisia allergy in the West.