| Author | L. | |
| Distribution | Mountains and Piedmont; absent from the Sandhills proper and almost all of the Coastal Plain.
N.S. to B.C., south to northern FL and CA. | |
| Abundance | Frequent to common in the Mountains and Piedmont; very rare in the Coastal Plain. Much less numerous in these regions than is Common Ragweed (A. artemisiifolia). | |
| Habitat | Alluvial forests, especially where disturbed, farm yards, fallow fields, pastures. Favors moist or rich soils. |
| Phenology | Flowering and fruiting July-October. | |
| Identification | Giant Ragweed is unmistakable, with its deeply 3-lobed (sometimes 5-lobed) leaves and great height (3-12 feet). Inflorescences are much like Common Ragweed, but grow from leafy branches as well as terminally. | |
| Taxonomic Comments | None
| |
| Other Common Name(s) | Great Ragweed | |
| State Rank | S5 | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FAC link |
