Ambrosia trifida

Ambrosia trifida
Ambrosia trifida, blooming flowers
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Asterales
Family:	Asteraceae
Subfamily:	Asteroideae
Tribe:	Heliantheae
Subtribe:	Ambrosiinae
Genus:	Ambrosia
Species:	A. trifida
Binomial name
Ambrosia trifida L. (1753) Source: IPNI

Common names

Buffalo Weed, Great Ragweed, Giant Ragweed, Bitterweed, Bloodweed, Horse Cane, Tall Ambrosia

Ambrosia trifida is an annual plant in the aster family, native throughout much of North America. Its flowers are green and are pollinated by wind rather than by insects, and the pollen is one of the main causes of late summer hay fever. Flowers are borne from midsummer through early fall.

The plant is erect, growing to over 6 meters, though 2– 3 meters is more typical.

As a weed

Giant Ragweed is one of the most competitive weeds found in North America. At average distributions it can reduce corn crop yields by 55% and soybean yields by 52%. It is very difficult to control Giant Ragweed through mechanical means or herbicides, but it does not tolerate mowing, so planting small grains in succession is an effective way to suppress infestations.

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  Record tall 21 foot Ambrosia trifida from Central Texas.

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  A. trifida growing in Denton, Texas, USA. Height = 5ft (1.5m)

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  A giant ragweed with only a few leaves - simple leaves appear first, then three-lobed leaves, and eventually five-lobed leaves.

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  Examples of simple and three-lobed leaves of A. trifida

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  A. trifida in Saratov Oblast, Russia. Height is approx. 8ft (2.5m)

References

• A. Davis, K. Renner, C. Sprague, L. Dyer, D. Mutch (2005). Integrated Weed Management. MSU.
• Everitt, J.H.; Lonard, R.L., Little, C.R. (2007). Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press.  ISBN 0-89672-614-2

External links

Media related to Ambrosia trifida at Wikimedia Commons

• Ambrosia trifida Photos, drawings, description from Nature Manitoba
• Giant Ragweed