Northern Prairie Wildlife Research Center
| Lead | Characteristic | Go To |
| 1 | Corolla lobes distinct, 2.5-6 mm long, the plicate membrane between the lobes toothed at the summit; stems puberulent on the decurrent leaf bases. | G. affinis |
| 1 | Corolla lobes low and indistinct, continuous with the erose plicate membrane; stems glabrous. | G. andrewsii |