| 1 | Leaves tripartite or undivided. |
| 1' | Most leaves with two or more pairs of lateral leaflets. |
| 2 | Leaves undivided or terminal leaflet at least 6 times as long as the lateral ones |
| 2' | Leaves tripartite, terminal leaflet not more than 3 times as long as the lateral ones. |
| 3 | Leaflets oblanceolate in outline. Plants usually very slender with internodes much longer than leaves |
| 3' | Leaflets ovate to orbicular in outline. Plants not very slender, with most internodes equalling or shorter than leaves. |
| 4 | Petals at least 6 mm long |
| 4' | Petals not exceeding 4 mm. |
| 5 | Pedicels of siliquae patent at an angle with stem exceeding 45° (usually c. 60°). Seeds at least 1.1 mm long |
| 5' | Pedicels of siliquae erect to erecto-patent (angle with stem c. 45° or less). Seeds shorter than 1.1 mm |
