Giant Ragweed, Great ragweed, Texan great ragweed, Bitterweed, Bloodweed, Buffalo Weed, Horse Cane

Ambrosia trifida

Physical Characteristics

Ambrosia trifida is a ANNUAL growing to 2 m (6ft 7in) at a medium rate. It is in flower from August to October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Eastern N. America - Quebec to Florida, west to Manitoba, Colorado and Mexico.

Habitats

Woodland Garden Cultivated Beds;

Edible Uses

Edible Parts: Oil Edible Uses: Oil This plant was cultivated by the pre-Columbian N. American Indians, seeds found in pre-historic sites are 4 - 5 times larger than those of the present-day wild plant, which seems to indicate selective breeding by the Indians[207]. The following report is for A. artemesifolia, it quite possibly also applies to this species[K]. An oil is obtained from the seed. It has been suggested for edible purposes because it contains little linolenic acid[61, 183]. The seed contains up to 19% oil[61], it has slightly better drying properties than soya bean oil[183].

Medicinal Uses

Antidote Astringent Emetic Poultice Skin Women's complaints The leaves are very astringent, emetic and febrifuge[222, 257]. They are applied externally to insect bites and various skin complaints, internally they are used as a tea in the treatment of pneumonia, fevers, nausea, intestinal cramps, diarrhoea and mucous discharges[222]. The juice of wilted leaves is disinfectant and is applied to infected toes[257]. A tea made from the roots is used in the treatment of menstrual disorders and stroke[222]. The pollen is harvested commercially and manufactured into pharmaceutical preparations for the treatment of allergies to the plant[222].

Known Hazards

The pollen of this plant is a major cause of hayfever in N. America[222]. Ingesting or touching the plant can cause allergic reactions in some people[222].