Chenopodium Ambrosioides Linn.

Synonyms:
Chenopodium ambrosioides (Linn.), Mexican Tea, Jesuit's Tea, Herba Sancti Mariae.

Parts Used:
Seeds and the entire plant.

Habitat:

Originally native to Mexico and South America, Chenopodium ambrosioides has naturalized across many regions, especially in the eastern United States — including Missouri and New England. Commonly known as the American Wormseed plant, it grows as a coarse, perennial roadside and waste-ground weed.

A notable variety, C. ambrosioides var. anthelminticum (Bert), is particularly valued for its medicinal properties.

Botanical Description:

This erect, angular, and grooved-stemmed plant can reach a height of around 2 feet. Its leaves are oblong-lanceolate, with toothed edges; the upper leaves are entire and taper at both ends.

The plant bears numerous small, yellowish-green flowers grouped in tight, globular clusters found in the axils of slender, leafy branches. The calyx is five-lobed with pointed, ovate lobes, and each flower contains five stamens.

The fruit is small, irregularly globular, and completely enclosed within the calyx. Light in weight, these fruits are greenish-yellow to brown, each containing a single, brownish-black, shiny seed. When rubbed, the fruit’s membranous outer layer comes off, exposing the aromatic seed.

The plant blooms from July to September, with fruits ripening through autumn and harvested in October.

Constituents of the Oil:

The seeds yield an essential oil known as American Wormseed Oil or Chenopodium Oil, which is initially colourless or yellowish but darkens with time and exposure.

Characteristics of the Oil:

• Odour: Penetrating, camphor-like aroma

• Taste: Pungent and bitter

• Oil yield: 0.6% to 1.0% from crushed seeds

• Specific gravity: 0.950–0.990

• Solubility: Soluble in three volumes of 70% alcohol

Note: Adulteration with American turpentine oil reduces the oil's specific gravity and affects its alcohol solubility.

Therapeutic Uses:

Chenopodium ambrosioides is a powerful anthelmintic (worm-expelling agent) particularly effective against lumbricoid (round) worms in children. It stands out for its:

• High efficacy

• Easy administration

• Low toxicity

Additional medicinal uses include:

• Treatment of malaria, chorea, hysteria, and various nervous system disorders

• Used traditionally under the name Herba Sancti Mariae for pectoral complaints, serving as an expectorant in cases of catarrh and asthma.

Possible side effects: Transient dizziness and vomiting if taken in excessive doses.