ODA rating: B USDA Symbol: AMAR2 Oregon ragweed distribution Click on image to view larger photo. | | Images courtesy of Western Society of Weed Science. |  |
If images are downloaded and used from the ODA web site please be sure to credit the photographer. Description Annual; blooms late summer. Grows to 4 foot tall. Stems and leaves blue-green and covered with fine hairs. Leaves divided and bottom sides covered in fine hairs, giving a gray appearance. Flowers inconspicuous and found on terminal branches. Impacts 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. Distribution in Oregon The first documented site of this plant in Oregon was 1909 in Josephine County.   Biological controls No approved biological control agent is available.
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