Ragweed, common (Ambrosia astemisiifolia L. var. elatior (L.) Descourtils)

Ragweed, common description

The plant has a shallow-rooted taproot. Stems stand erect, multi-branched and may be hairless or hairy. Leaves are hairy to nearly smooth, mostly alternate and are deeply cut into many lobes. Plant grows up to 6 ft tall and emits strong odor when crushed.

Seedling

Opposite first leaves with stems. Cotyledons are spatula-shaped with purple spots on margin.

Mature plant

Stems erect, branched, bushy, 1/2 to 5 feet tall at maturity. Hairless to hairy.

Leaves opposite at bottom of plant, becoming alternate above. Ovate but deeply divided with coarse, toothed edges. Bright green to yellow-green on young plants. Older plants with gray-green leaves. Smooth upper leaves, hairy to hairless underneath. Stalks short.

Root structure description

Taproot.