By Harold McGee
Epazote is a scented member of the large “goosefoot” family, which also provides us with spinach, beets, and the grain quinoa. Chenopodium ambrosioides is a weedy native of temperate central America that has spread throughout much of the world, and lends a characteristic aroma to Mexican beans, soups, and stews. That aroma is variously described as fatty, herbaceous, and penetrating, and is due to a terpene called ascaridole. Ascaridole is also responsible for the use of epazote in folk medicine; it is toxic to intestinal worms.