| 1 | Tepals longer than 5 mm, caducous. Ovules 2. Plant stoloniferous. |
| 1' | Tepals shorter than c. 3 mm, persistent. Ovules 4-8. Plant not stoloniferous. |
| 2 | Testa double. Tepals yellow. |
| 2' | Testa simple. |
| 3 | Cross-veins at a ± 50° angle. Tepals yellow. Filaments only slightly widening towards the base. Fruit with a terminal beak. |
| 3' | Cross-veins at a ± 70° angle. Tepals white or cream. Filaments strongly widened and applanate. Fruit with a short lateral beak. |
