| 1 | Buds and flowers erect, the inflorescence erect or somewhat drooping. |
| 1' | Buds and flowers drooping, becoming erect in fruit. |
| 2 | Stems pubescent only along conspicuously elevated lines running down from the margins of the petioles |
| 2' | Stems pubescent all around. |
| 3 | Upper leaves strongly reduced. Inflorescence slightly nodding (Luzon). |
| 3' | Upper leaves not notably reduced. Inflorescence erect (Java, Lesser Sunda Is., New Guinea). |
| 4 | Leaves ovate, 0.4-1.5 cm wide |
| 4' | Leaves very narrowly elliptic to linear, 0.1-0.5 cm wide |
| 5 | Plants finely glandular-pubescent; leaves usually ericoid in appearance; petals purplish-rose |
| 5' | Plants densely strigulose; leaves broader, not ericoid; petals white or very pale pink |
| 6 | Stems with elevated glabrous lines running from the center of each petiole and elevated pubescent lines from their angles; petals 7-14 mm long |
| 6' | Stems without elevated lines, uniformly pubescent all around; petals 2.5-8.5 mm long. |
| 7 | Petals 6-8.5 mm long; seeds 1-1.4 mm long |
| 7' | Petals 2.5-5(-6) mm long; seeds 0.7-0.9 mm long |
