| 1 | Undersurface of leaves pubescent |
| 1' | Undersurface of leaves glabrous. |
| 2 | Leaves more than 15 cm long. |
| 2' | Leaves less than 15 cm long. |
| 3 | Principal lateral veins of undersurface less distinct, scarcely raised above the surface. Leaves usually elliptic to broad-elliptic |
| 3' | Principal veins on undersurface prominent, raised above the surface. Leaves usually oblong-lanceolate to lanceolate. |
| 4 | Leaves oblong-elliptic to narrowly oblong |
| 4' | Leaves lanceolate (N. Luzon) |
| 5 | Leaves lanceolate-oblong |
| 5' | Leaves elliptic to elliptic-oblong. |
| 6 | Venation on lower surface prominent, raised above the surface. Lamina, petiole, and young branches green |
| 6' | Venation on lower surface less distinct, scarcely raised. Lamina, petiole, and young branches olivaceous |
