Common ragweed – Ambrosia artemisiifolia

Common ragweed – Ambrosia artemisiifolia

Ambrosia artemisiifolia L.

Asteraceae (Aster family)

MI Status

Native

Life cycle

Erect, branching summer annual.

Leaves

Cotyledons are thick and oval to spatula-shaped. Leaves are fernlike, once or twice compound and usually hairy. Upper leaves are alternate; lower leaves may be opposite or alternate with distinct petioles.

Stems

Usually hairy, erect and branched up to 6 feet tall.

Flowers and fruit

Flowers are generally inconspicuous, found on terminal branches. They produce prolific amounts of pollen. The seed is enclosed in a single-seeded, woody fruit with several spikes resembling a crown.

Reproduction

Seeds.

Similar weeds

Giant ragweed (A. trifida L.)
Differs by having cotyledons three to four times larger; three- to five-lobed leaves opposite in arrangement; and a height that may reach 15 feet.
Western ragweed (A. psilostachya DC.)
Differs by having a perennial nature with prolific creeping roots, densely hairy leaves and a height typically not above 4 feet.

Accessibility Questions:

For questions about accessibility and/or if you need additional accommodations for a specific document, please send an email to ANR Communications & Marketing at anrcommunications@anr.msu.edu.

Plant & Pest Diagnostics