Common ragweed – Ambrosia artemisiifolia

The photo is of a common ragweed seedling. Leaves are fernlike, once or twice compound, and usually hairy.

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 being perennial, with prolific creeping roots, densely hairy leaves, and a height typically not exceeding 4 feet.

The photo is of a common ragweed leaf. They are fernlike, compound and usually hairy. — Common ragweed leaf

The photo is of a common ragweed flowering branch. They are green and inconspicuous in clusters on terminal branches. — Common ragweed flowering branch

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