| Gramen Ség., 1754 |
| Gramerium Desv., 1831 |
| Graminastrum E.H.L. Krause, 1914 |
| Graphephorum Desv., 1810 |
| Graphephorum altijugum E. Fourn., 1886 |
| Graphephorum densiflorum E. Fourn., 1877 |
| Greenia Nutt., 1835 |
| Greenia arkansana Nutt., 1835 |
| Griffithsochloa G. J. Pierce, 1978 |
| Griffithsochloa multifida (Griffiths) G.J. Pierce, 1978 |
| Guadua Kunth, 1822 |
| Guadua (Kunth) Hack., 1887 |
| Guadua aculeata Rupr. ex E. Fourn., 1886 |
| Guadua aculeata var. aculeata Rupr. ex E. Fourn., 1886 |
| Guadua aculeata var. liebmanniana E.G. Camus, 1913 |
| Guadua amplexifolia J. Presl, 1830 |
| Guadua angustifolia Kunth, 1822 |
| Guadua angustifolia var. bicolor Londoño, 1989 |
| Guadua flabellata E. Fourn., 1885 |
| Guadua inermis Rupr. ex E. Fourn., 1886 |