| | 1. Basal leaves with 4–10 pairs of lateral lobes; pedicel > 1 mm thick; fruit > 4 cm |
| B. verna |
| | 1' Basal leaves generally with < 4 pairs of lateral lobes; pedicel < 1 mm thick; fruit generally < 3 cm |
| |
| | 2. Style in fruit stout, < 1 mm; petals pale yellow; upper cauline leaves pinnately lobed; native |
| B. orthoceras |
| | 2' Style in fruit slender, 1.5–3 mm; petals bright yellow; upper cauline leaves entire to coarsely dentate; alien |
| B. vulgaris
|