| 1 | Plants flowering in autumn, generally in advance of the development of the leaves |
| 1' | Plants flowering in spring, with or after the development of the leaves |
| 2 | Inflorescence a many-flowered raceme with c. 40-150 flowers |
| 2' | Inflorescence a lax raceme, usually with 2-6 flowers |
| 3 | Flowers with a distinct perianth-tube |
| 3' | Flowers without a distinct perianth-tube |
