Chenopodium ambrosioides anthelminticum (L.) A. Gray.
Synonym: Chenopodium anthelminticum L.
Other common names: Chenopodium, American wormseed, Jerusalem-oak.
Habitat and range: Wormseed occurs in waste places from New England to Florida and westward to California.
Description: This common weed has a much-branched stem from 2 to 3 feet in height and numerous, lance-shaped leaves, the lower ones 1 to 3 inches in length and the upper ones much smaller. The greenish flowers are produced from July to September in closely crowded spikes mixed with leaves and are followed by small, green, roundish fruits each of which contains a very small black seed. The entire plant has a strong, disagreeable odor due to the volatile oil which is present.
Part used: The fruit, collected when ripe, and the volatile oil distilled from the fruit or from the entire plant. Wormseed is grown commercially mainly in central Maryland for the production of the oil.
