| 1 | Fruit a siliqua, i.e. less than three times as long as broad. Ovary ovoid to pyriform. |
| 1' | Fruit a siliqua, i.e. more than three times as long as broad. Ovary ± cylindrical. |
| 2 | Silicule with two seeds, orbicular, elliptic in outline |
| 2' | Silicule with more than two seeds, triangular in outline |
| 3 | Siliqua corky-spongy, non-dehiscent |
| 3' | Siliqua opening by two valves. |
| 4 | Siliqua narrowing into a conical beak (rostrum), terminated by the style |
| 4' | Siliqua without a rostrum, ± abruptly terminated by the style. |
| 5 | Siliqua with a thickened replum (i.e. thickened edge of the septum of the siliqua, on which the seeds grow), explosively dehiscent by coiling valves |
| 5' | Siliqua with a thin replum; valves opening without coiling |
