Scientific name Ambrosia acanthicarpa Rank Species | Genus Ambrosia Higher classification Ragweed | |
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Similar Ragweed, Daisy family, Ambrosia tomentosa, Ambrosia confertiflora, Ambrosia psilostachya | ||
Ambrosia acanthicarpa is a North American species of bristly annual plants in the sunflower family. Members of the Ambrosia genus are called ragweeds. The species has common names including flatspine bur ragweed, Hooker's bur-ragweed, annual burrweed, and annual bur-sage, and western sand-bur. The plant is common across much of the western United States and in the 3 Prairie Provinces of Canada.
This spiny, weedy plant grows in clumps of many erect stems which may reach over a meter in height. Its gray-green stems are covered in a coat of stiff, bristly hairs. The few rough leaves are several centimeters long. The racemes of flowers are more plentiful, with each hairy flower head a few millimeters wide. The spiny, burr-like pistillate heads have pointed, twisting bracts and the staminate heads are rounded. The species is adaptable and grows well in disturbed areas, easily becoming weedy.
