Practical
Plants

Ambrosia trifida

Giant Ragweed

an annual member of the Ambrosia genus in the family Compositae.

No photo available

Taxonomy and growth

Life cycle
annual
Height
2 m
Fertility
Wind
Flower type
monoecious
Pollinators
Wind

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

The pollen of this plant is a major cause of hayfever in N. America[3]. Ingesting or touching the plant can cause allergic reactions in some people[3].

Edible uses

This section contains historical Plants For A Future notes marked noncommercial.

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[2]. 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[7][1]. The seed contains up to 19% oil[7], it has slightly better drying properties than soya bean oil[1].

Product or use
Oil

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

The leaves are very astringent, emetic and febrifuge[3][5]. 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[3]. The juice of wilted leaves is disinfectant and is applied to infected toes[5]. A tea made from the roots is used in the treatment of menstrual disorders and stroke[3]. The pollen is harvested commercially and manufactured into pharmaceutical preparations for the treatment of allergies to the plant[3].

Product or use
Antidote
Product or use
Astringent
Product or use
Emetic
Product or use
Poultice
Product or use
Skin
Product or use
Women's complaints

Material uses

This section contains historical Plants For A Future notes marked noncommercial.

A red colour is obtained from the crushed heads[2]. (This probably refers to the seed heads[K].) The sap of the plant can stain the skin red[6].

Product or use
Dye

Environment

Range
Eastern N. America - Quebec to Florida, west to Manitoba, Colorado and Mexico.
Habitat
Alluvial waste places, sometimes forming vast pure stands[3].
Light
full sun
Shade tolerance
light shade
Water
moderate
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Seed - we have no details for this species but suggest sowing the seed in situ in April.

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

We have very little information on this species but suggest growing it in a sunny position in a well-drained soil[K]. This plant is sometimes cultivated by the N. American Indians for food and medicine[2].

References

  1. Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9

    ↩1↩2

  2. Coffey. T. The History and Folklore of North American Wild Flowers. Facts on File. 1993-00-00 ISBN 0-8160-2624-6

    ↩1↩2↩3

  3. Foster. S. & Duke. J. A. A Field Guide to Medicinal Plants. Eastern and Central N. America. Houghton Mifflin Co. 1990-00-00 ISBN 0395467225

    ↩1↩2↩3↩4↩5↩6↩7

  4. Britton. N. L. Brown. A. An Illustrated Flora of the Northern United States and Canada Dover Publications. New York. 1970-00-00 ISBN 0-486-22642-5

  5. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9

    ↩1↩2

  6. Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm

    ↩

  7. Usher. G. A Dictionary of Plants Used by Man. Constable 1974-00-00 ISBN 0094579202

    ↩1↩2

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