Epazote (Chenopodium ambrosiodes) is a plant commonly used in Mexican and South American cooking. The leaves of the plant are used fresh or dried in bean dishes, salsas, and sometimes as a medicinal tisane. The term epazote is derived from the Nahulatl language and means "animal with a rank odor." Indeed, the leaves have a pungent fragrance, but with pleasant hints of lemon. Epazote might not sound appetizing, but in small amounts it lends a spike of flavor to the right dish. About one tablespoon of dried epazote can be added to a pot of chili or bean soup for seasoning. Epazote is frequently used in bean dishes because it allegedly hinders the production of gastrointestinal gas.
Epazote is believed to have various medicinal properties. It has been used to treat animals with parasitic worms for centuries. Like other medicinal herbs, it is toxic in large amounts.
Epazote is an annual but can be grown as a perennial in mild climates. It grows approximately .5m to 1.5m tall and prefers sandy, moist soil and plenty of sunlight. Common names for epazote include Mexican tea, goosefoot, wormseed, skunkweed (not to be confused with skunk cabbage), and Jerusalem oak.
Some nurseries sell the seeds for cultivation, and the dried leaves can be bought from specialty spice merchants or at Mexican groceries.
The following gardening site set up by Cornell University has more information on epazote: http://www.dnr.cornell.edu/gardenmosaics/pages/science/mainscience.htm.