| To Codes in: | A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | R | S | T | U | V | W | Z |
| GAPH2 | Gastridium phleoides | nit grass |
| GASTR | Gastridium sp. | gastridium |
| GLAR | Glyceria arkansana | arkansas mannagrass |
| GLSE3 | Glyceria septentrionalis | floating mannagrass |
| GLYCE | Glyceria sp. | mannagrass |
| GLST | Glyceria striata | fowl mannagrass |
| GYAM | Gymnopogon ambiguus | bearded skeletongrass |
| GYBR | Gymnopogon brevifolius | shortleaf skeletongrass |
| GYMNO3 | Gymnopogon sp. | skeletongrass |