A native of Europe and Asia, now widespread in the western U.S., infesting croplands and non-croplands.
An annual broadleaf weed that grows very large and upright. Seeds begin germinating in early to late winter, and plants mature in mid to late summer.
A large shrub with aromatic foliage. Leaves thickly covered with short hairs and have a distinct sticky feel to them. Mature plants grow upright as numerous stems growing out of a central point at the ground. Stems grow as tall as 2 feet.
Leaves are oval with very wavy margins that are divided into shallow lobes. Upper leaves may have smooth margins.
Flowers are arranged as thick clusters on the ends of leafless panicles. The flower itself is very small, hairy, and without colored petals.
Characteristicts Important to Control:
Sandy soils are particularly conducive to the plant’s growth – huge seed production hinders pre-emergent herbicide control.