Northern Prairie Wildlife Research Center
| Lead | Characteristic | Go To |
| 1 | Pedicels 2-5 mm long, shorter than to as long as the calyx; corolla (17)20-32 mm long. | A. purpurea |
| 1 | Pedicels 8-20 mm long, longer than the calyx; corolla 8-15 mm long. | A. tenuifolia |