Ambrosia acanthicarpa
Encyclopedia
Ambrosia acanthicarpa is a species of ragweed
known by the common names flatspine burr ragweed, annual burrweed, and annual bur-sage.
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 raceme
s of flowers are more plentiful, with each hairy flower head a few millimeters wide. The spiny, burr-like pistillate heads have pointed, twisting bract
s and the staminate
heads are rounded. This ragweed is native to western North America. It is adaptable and grows well in disturbed areas, easily becoming weedy.
Ragweed
Ragweeds are flowering plants in the genus Ambrosia in the sunflower family Asteraceae. Common names include bitterweeds and bloodweeds....
known by the common names flatspine burr ragweed, annual burrweed, and annual bur-sage.
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 raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
s of flowers are more plentiful, with each hairy flower head a few millimeters wide. The spiny, burr-like pistillate heads have pointed, twisting bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s and the staminate
Stamen
The stamen is the pollen producing reproductive organ of a flower...
heads are rounded. This ragweed is native to western North America. It is adaptable and grows well in disturbed areas, easily becoming weedy.