Skeletonleaf Bursage

Ambrosia tomentosa

Family: Asteraceae

Weed class: monitor list

Why Is It a Noxious Weed?

This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact the State Noxious Weed Board to report locations or for more information.

How would I identify it?

General Description

Perennial herbacous plant that grows 20-60 cm (7.8-23.6 inches) tall.

Flower Description

Flowers are monoecious with male flowers in small drooping heads along the stems tips and female flower 1-2 in upper leaf axils.

Leaf description

Leaves are alternately arranged, 5-12 cm (2-4.7 inches), and mostly bipinnately lobed, with lobes being narrow and irregularly shaped. Leaves are green to grayish in color, smooth to hairy above, and white tomentose on the undersides.

Where does it grow?

Grows in open areas such as fields, pastures and disturbed sites, especially moist, irrigated, poorly drained places. Also grows in dry regions and plains. One location historically known to have occurred in Franklin County. Previously on the noxious weed list in 1989 and 1990.