Ambrosia artemisiifolia

annual ragweed, common ragweed, ragweed, low ragweed, roman wormwood, short ragweed, small ragweed, altamisa


Leaf Arrangement

alternate, opposite

Leaf Attachment


Leaf Type


Growth Form


Flower Color

green, inconspicuous, yellow

Flower Month


Height (meters)

0.2 - 2.0

Milky Sap





introduced, native



Growing Season

Warm season

Wetland Class


Wetland Coefficient of Conservatism


Prairie Coefficient of Conservatism


Field Characters

Similar to western ragweed which is rhizomatous and difficult to pull from the ground while annual ragweed is easily pulled up. Lower leaves opposite, upper alternate.

Cultural Information

Seed germination appears to be favored by alternating temperatures and light (Maguire and Overland 1959). Germination was dramatically increased by moist and dry stratification. Seedling identification: Underside of cotyledons (seed leaves) is deep purple. Stem below seed leaves is usually green with purple splotches. Densely hairy over entire leaf surface.

Animal Use

A high-use forage plant for white-tail deer in spring and summer. Deer also eat giant ragweed. Ragweed seeds are one of the most important quail foods based on volume consumed. The following Information is for the genus Ambrosia with notation that A. artemisiifolia and A. psilostachya are the most useful to wildlife while A. trifida is of little value: Animals that eat its seeds: Yellow rail, Wilson snipe, Ground dove, Mourning dove, Attwater's prairie chicken, Bobwhite quail, Wild turkey, Woodcock, Redwing blackbird, Cardinal, Purple finch, Eastern goldfinch, Chipping sparrow, English sparrow, Harris sparrow, Eastern lark sparrow, Lincoln sparrow, Savannah sparrow, Tree sparrow, Eastern vesper sparrow, White-crowned sparrow, Meadow mouse, and White-tailed deer. Animals that eat its foliage: White-tail deer and cottontail rabbit (Martin et al. 1951).

Natural History

A major allergen and irritant to hay fever sufferers. Ragweed blooms in the fall at the same time as Senecio glabellus (yellowtop or butterweed) and Solidago canadensis (goldenrod) which is showy and often gets the blame for allergic reactions and hay fever. Ragweed is wind pollinated and consequently has inconspicuous flowers. The Acadians of south Louisiana call common ragweed "massicot" (Holmes 1990).


Open mixed grass prairies and roadsides.