common ragweed
Ambrosia artemisiifolia L.


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 United States 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.
Herbicide Resistance
Populations of this plant exist in the United States that are resistant to ALS inhibitors (B/2),Photosystem II inhibitors (C1/5), PPO inhibitors (E/14), Glycines (G/9)

Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

State Regulated List
   No Data for this state
   Troublesome or Common weed in one or more crops

Most Troublesome / Most Common Agricultural Weed List
This map identifies those states that consider this species either most troublesome or most common in at least one commodity. For more information, visit the MTMC project page.

Invasive Listing Sources

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Ambrosia
Subject: Ambrosia artemisiifolia L.

Synonyms and Other Names

Other Common Names:
annual ragweed, common ragweed, low ragweed, ragweed, Roman wormwood, short ragweed, small ragweed


Plants - Forbs/Herbs