- Ambrosia artemisiifolia is an annual. It blooms in the late summer and it can grow up to 4 ft. (1.2 m) tall.
- Stems and leaves are blue-green and covered with fine hairs. Leaves divided and bottom sides covered in fine hairs, giving a gray appearance.
- Flowers inconspicuous, yellowish-white, and found on terminal branches.
- Fruits are yellowish to reddish brown, woody, spined, ridged, and crow like in appearance. Seeds are 0.12-0.16 in. (3-4 mm) long.
- Ecological Threat
- This plant is common throughout the West and causes hay fever in many people. It is commonly found along ditches and waste areas. It is not highly competitive in crops or rangeland. Native to all U.S. states except Hawaii and Alaska.
Global Invasive Species Database. 2011. Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission 
CABI Invasive Species Compendium 
United States Geological Survey 
USDA NRCS PLANTS 
USDA ARS GRIN 
Images from Bugwood.org