Northern Prairie Wildlife Research Center
| Lead | Characteristic | Go To |
| 1 | Leaves all basal, strongly whitened beneath | Genus Primula |
| 1 | Leaves cauline, green on both surfaces. | Lead 2 |
| 2 | Flowers white to pinkish, solitary and sessile in the leaf axils; corolla absent, the perianth comprised of a petaloid calyx. | Genus Glaux |
| 2 | Flowers yellow, solitary and pedicellate from the axils, or in axillary racemes; calyx and corolla both present. | Genus Lysimachia |