About Ambrosia acanthicarpa Hook.
Ambrosia acanthicarpa Hook. is a North American bristly annual plant species belonging to the Asteraceae family. Plants in the Ambrosia genus are commonly known as ragweeds. This species has several common names: flatspine bur ragweed, Hooker's bur-ragweed, annual burrweed, annual bur-sage, and western sand-bur. It is common across a large portion of the western United States, as well as in the Prairie Provinces of Canada. This spiny weedy plant grows in clumps made up of many erect stems that can reach over 1 meter in height. Its gray-green stems are covered in a layer of stiff, bristly hairs. It produces a small number of rough leaves that are several centimeters long. It bears plentiful racemes of flowers; each hairy flower head is a few millimeters wide. The spiny, burr-like pistillate heads have pointed, twisting bracts, while the staminate heads are rounded. This adaptable species grows well in disturbed areas and easily becomes weedy.
