Northern Prairie Wildlife Research Center
| Lead | Characteristic | Go To |
| 1 | Leaves once-pinnate; roots fibrous; primary veins of the leaflets directed toward the teeth of the margin. | Lead 2 |
| 1 | Leaves 2-3X pinnate; roots usually partly tuberous; primary veins of the leaflets directed toward the sinuses between the teeth of the margin. | Genus Cicuta |
| 2 | Leaflets of upper leaves irregularly incised; fruits with obscure ribs. | Genus Berula |
| 2 | Leaflets of upper leaves regularly serrate; fruits with conspicuous ribs. | Genus Sium |