| | 1. Fruit narrowly awl-like, beaked; pedicel erect to ascending, ± appressed |
| S. officinale |
| | 1' Fruit linear, beak 0; pedicel spreading to ascending, not appressed |
| |
| | 2. Upper cauline leaves with lobes or leaflets thread-like to linear, terminal ± = lateral; pedicel in width ± = or > fruit; outer 2 sepals with erect horns at tip |
| S. altissimum |
| | 2' Upper cauline leaves ± entire or with lobes or leaflets lanceolate to triangular, lanceolate, terminal > lateral; pedicel in width ± = to << fruit; sepal horns 0 |
| |
| | 3. Pedicel width ± = fruit width |
| |
| | 4. Petals 1.5–3 mm; fruit 2–4(5) cm, upper cauline leaf margins dentate |
| S. erysimoides |
| | 4' Petals generally 8–10 mm; fruit 3–10 cm; upper cauline leaf margins entire to few-toothed |
| S. orientale |
| | 3' Pedicel in width < fruit width |
| |
| | 5. Stem branched from near base; fruits generally overtopping flowers, generally 3–4 cm; hairs 0 or above, few, ± short |
| S. irio |
| | 5' Stem branched especially above; fruits generally not overtopping flowers, 2–3.5 cm; hairs at least on lower stems, long |
| S. loeselii
|