common ragweed USDA PLANTS Symbol: AMAR2
U.S. Nativity:
Habit: Forbs/Herbs
Ambrosia artemisiifolia L.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): annual ragweed, common ragweed, low ragweed, ragweed, Roman wormwood, short ragweed, small ragweed

Appearance
Ambrosia artemisiifolia is an annual. It blooms in the late summer and it can grow up to 4 ft. (1.2 m) tall.
Foliage
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
Flowers inconspicuous, yellowish-white, and found on terminal branches.
Fruit
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 from Invasive.orgView All Images at Invasive.org


Plant(s); in flower
Ohio State Weed Lab , The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); May. Photo from Forest Plants of the Southeast and Their Wildlife Uses by J.H. Miller and K.V. Miller, published by The University of Georgia Press in cooperation with the Southern Weed Science Society.
James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); September. Photo from Forest Plants of the Southeast and Their Wildlife Uses by J.H. Miller and K.V. Miller, published by The University of Georgia Press in cooperation with the Southern Weed Science Society.
James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); October. Photo from Forest Plants of the Southeast and Their Wildlife Uses by J.H. Miller and K.V. Miller, published by The University of Georgia Press in cooperation with the Southern Weed Science Society.
James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
John D. Byrd, Mississippi State University, Bugwood.org
Additional Resolutions & Image Usage

Seedling(s);
John D. Byrd, Mississippi State University, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Bruce Ackley, The Ohio State University, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources: