| 1 | Inflorescence several times dichotomously branched; usually lianas. |
| 1' | Inflorescences thyrsoid; usually small trees or shrubs. |
| 2 | Stamens stigmas and ovary locules 3. |
| 2' | Stamens, stigmas and ovary locules 5. |
| 3 | Peduncle short, to 1.2 cm long; inflorescence to 5 cm long; leaf margin entire, (undulate-)crenate or serrate; flowers 2-2.5 mm diam.; fruit with ribs or ridges. |
| 3' | Peduncle to 3 cm long; inflorescence to 13 cm long; leaf margin entire; flowers 2-4.5 mm diam.; fruit smooth or lenticellate. |
| 4 | Stigmas entire; petals less than 0.8 mm long. |
| 4' | Stigmas bilobed; petals 0.8-1.5 mm long; fruit often with 6-l 0 lines or ridges from the base (when dried). |
