Botanical name: 

Preparations: Oil of Chenopodium

Chenopodium. Chenopodium. American Wormseed.—The fruit of C. Ambrosioides var. anthelminticum (L.) Gray (Fam. Chenopodiaceae). This species of Chenopodium, known commonly by the names of wormseed and Mexican Tea, grows in almost all parts of the Eastern United States. The whole herb has a strong, peculiar, offensive, yet somewhat aromatic odor, which it retains when dry. All parts of the plant are occasionally employed, but the fruit alone was official in the U. S. P., 1890. This should be collected in October.

Wormseed, as found in commerce, is a small fruit, about 2 mm. in diameter, having a membranaceous pericarp, irregularly spherical, very light, of a dull greenish-yellow or brownish color, a bitterish, somewhat aromatic, pungent taste, and possessed in a high degree of the peculiar odor of the plant. These fruits, when deprived, by rubbing them in the hand, of the membranaceous covering which invests the proper seed, exhibit the shining, blackish surface of the obtusely-edged seed. They abound in a volatile oil, upon which their sensible properties and medicinal virtues depend and which is obtained by distillation. (See Oleum Chenopodii) The same oil impregnates to a greater or less extent the whole plant.

Of the activity of the wormseed as an anthelmintic there can be no question, but it has been entirely displaced by the official oil. The dose of the crude drug is from twenty to forty grains (1.3-2.6 Gm.).

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.