| Gaillardia pulchella var. pulchella | Fire-wheel Blanket-flower |
| Galanthus nivalis | Snowdrops |
| Galearis spectabilis | Showy Orchis |
| Galinsoga quadriradiata | Fringed Quickweed |
| Galium aparine | Catchweed Bedstraw |
| Galium circaezans var. circaezans | Southern Forest Bedstraw |
| Galium mollugo | Madder Bedstraw |
| Galium obtusum subsp. obtusum | Blunt-leaf Bedstraw |
| Galium verum | Yellow Spring Bedstraw |
| Gaylussacia baccata | Black Huckleberry |
| Gaylussacia brachycera | Box Huckleberry |
| Gentiana andrewsii var. andrewsii | Closed-bottle Gentian |
| Gentiana catesbaei | Elliott's Gentian |
| Gentiana crinita | Fringed Gentian |
| Gentiana saponaria | Soapwort Gentian |
| Gentiana villosa | Striped Gentian |
| Gentianopsis crinita | Fringed Gentian |
| Geranium carolinianum | Carolina Crane's-bill |
| Geranium columbinum | Long-stalk Crane's-bill |
| Geranium maculatum | Wild Geranium |
| Geranium molle | Dovesfoot Crane's-bill |
| Geranium pusillum | Small-flower Crane's-bill |
| Geranium robertianum | Robert's Crane's-bill |
| Gerardia purpurea | Large-purple False Foxglove |
| Gerardia racemulosa | Large-purple False Foxglove |
| Geum canadense | White Avens |
| Geum vernum | Spring Avens |
| Glechoma hederacea | Ground-ivy |
| Gleditsia triacanthos | Honey-locust |
| Gnaphalium obtusifolium | Fragrant Cudweed |
| Goodyera pubescens | Downy Rattlesnake-plantain |