| 1. Involucres cylindric; phyllaries 46 |
| G. microcephala |
| 1' Involucres obconic or bell-shaped; phyllaries 12 or more |
| |
| 2. Ray flowers 413; disk flowers 413; total flowers 820; heads generally solitary |
| G. californica |
| 2' Ray flowers 28; disk flowers 29; total flowers 814; heads generally in clusters of 25 |
| G. sarothrae
|