| Gonzalezia rosei (Greenm.) E.E. Schill. & Panero, 2011 |
| Gorteria L., 1759 |
| Graciela Rzed., 1975 |
| Graciela frankenioides Rzed., 1975 |
| Greenella A. Gray, 1880 |
| Greenella arizonica A. Gray, 1880 |
| Greenella discoidea A. Gray, 1883 |
| Greenella ramulosa Greene, 1889 |
| Greenmaniella W.M. Sharp, 1935 |
| Greenmaniella resinosa (S. Watson) W.M. Sharp, 1935 |
| Grindelia Willd., 1807 |
| Grindelia aphanactis Rydb., 1904 |
| Grindelia arizonica A. Gray, 1882 |
| Grindelia confusa Steyerm., 1938 |
| Grindelia eligulata (Steyerm.) G.L. Nesom, 1990 |
| Grindelia glandulosa Greenm., 1899 |
| Grindelia grandiflora Hook., 1852 |
| Grindelia greenei Steyerm., 1934 |
| Grindelia greenmanii Steyerm., 1934 |
| Grindelia havardii Steyerm., 1934 |