| Fagopyrum esculentum | Buckwheat |
| Fagus grandifolia | American Beech |
| Fallopia japonica | Japanese Knotweed |
| Fallopia scandens | Crested Climbing Buckwheat. |
| Festuca arundinacea | Kentucky Fescue |
| Festuca elatior | Kentucky Fescue |
| Ficaria verna | Lesser Celandine |
| Floerkea proserpinacoides | False Mermaidweed |
| Foeniculum vulgare | Sweet Fennel |
| Forsythia ×intermedia | Forsythia |
| Fragaria virginiana | Virginia Strawberry |
| Froelichia floridana | Florida Cottonweed |
| Froelichia gracilis | Slender Cottonweed |
| Frullania asagrayana | Frullania |