| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Asteraceae | Ambrosia trifida var. texana | Texas Giant Ragweed | Floodplains, moist pastures; disturbed ground. | S. IL and MO south to MS, s. TX, and Mexico (CHH, COA, HGO, QRO, SON, TAM, VER). |  |
| Asteraceae | Ambrosia trifida var. trifida | Giant Ragweed | Floodplains, moist pastures, disturbed ground. | NS and BC south to n. peninsular FL, Panhandle FL, TX, and CA. Report from s. FL (Kartesz 2022) is false, based on misidentified specimen. |  |