| 1 | Midrib prominent on the upper surface |
| 1' | Midrib impressed in the upper surface. |
| 2 | Twigs hairy. |
| 2' | Twigs glabrous. |
| 3 | Leaves distichous |
| 3' | Leaves spirally arranged. |
| 4 | Underside of leaves glabrous. |
| 4' | Underside of leaves hairy. |
| 5 | Fruits 8-25 mm |
| 5' | Fruits 5-7 mm |
| 6 | Upper side of leaves hairy (pulverulent) |
| 6' | Upper side of leaves glabrous. |
| 7 | Seeds not straight. Embryo at least U-shaped curved. |
| 7' | Seeds straight. Embryo at most slightly curved. |
| 8 | Fruits ampulliform. Inflorescence a (basally branched) spike. Bracts persistent. Seeds twice curved |
| 8' | Fruits not ampulliform. Inflorescence a panicle. Bracts caducous. Seeds U-shaped |
| 9 | Leaf index more than 3. Leaf margin (and petiole) beset with closely spaced glands. Stone not ampulliform |
| 9' | Leaf index 2-3. Leaf margin (and petiole) often glandular but glands not closely spaced. Stone ampulliform |
| 10 | Fruits ampulliform |
| 10' | Fruits spindle-shaped or otherwise not ampulliform. |
| 11 | Inflorescence a (basally branched) spike or a cone. |
| 11' | Inflorescence not a spike (rarely a cone in bud). |
| 12 | Angle of leaf base less than 60°. Fruits 20-40 mm long |
| 12' | Angle of leaf base more than 60°. Fruits to c. 10 mm long. |
| 13 | Terminal buds large (7-10 mm) |
| 13' | Terminal buds small. |
| 14 | Inflorescence a panicle. Embryo curved |
| 14' | Inflorescence a (basally branched) raceme. Embryo straight |
