| 1 | Midrib prominent on the upper surface. |
| 1' | Midrib impressed on the upper surface. |
| 2 | Twigs hairy. Terminal buds hairy, small. Seeds straight |
| 2' | Twigs glabrous. Terminal buds glabrous. Seeds curved |
| 3 | Underside of leaves glabrous. |
| 3' | Underside of leaves hairy. |
| 4 | Twigs hairy. |
| 4' | Twigs glabrous. |
| 5 | Leaves distichous |
| 5' | Leaves spirally arranged. |
| 6 | Leaves crowded towards the end of the twigs. Twigs thick, tapering towards apex. Petiole more than 20 mm. Apex of leaves rounded or acute |
| 6' | Leaves evenly distributed. |
| 7 | Fruits ampulliform. Inflorescence a (basally branched) spike. Seeds not straight. |
| 7' | Fruits ellipsoid. |
| 8 | Fruits 10-12 mm long. Inflorescence a fascicle. Bracts persistent |
| 8' | Fruits 7-10 mm long. Inflorescence a (basally branched) raceme. Bracts caducous |
| 9 | Nerves less than 5 pairs |
| 9' | Nerves more than 5 pairs. |
| 10 | Leaves distichous |
| 10' | Leaves spirally arranged. |
| 11 | Inflorescence a (basally branched) spike. |
| 11' | Inflorescence not a spike (rarely a cone in bud). |
| 12 | Fruits ovoid to orbicular, 9-10 mm long. Twigs thick. Terminal buds large |
| 12' | Fruits ampulliform to globose, 5-7 mm long. |
| 13 | Bracts persistent. |
| 13' | Bracts caducous. |
| 14 | Petiole 12-17 mm. Fruits ellipsoid. Inflorescence a fascicle |
| 14' | Petiole 3-9 mm. Fruits ampulliform. Inflorescence a raceme or panicle. |
| 15 | Fruits 1-celled. Inflorescence a rusty tomentellous panicle |
| 15' | Fruits 2-3-celled. Inflorescence a raceme. |
| 16 | Leaf margin entire. Fruits c. 10 mm. Seeds straight |
| 16' | Leaf margin not entire. Fruits 4-10 mm, the sterile cells larger than the fertile ones, towards the base filled with air |
| 17 | Twigs glabrous. |
| 17' | Twigs hairy. |
| 18 | Leaves distichous. Petiole 1-4 mm |
| 18' | Leaves spirally arranged. Petiole more than 10 mm. |
| 19 | Inflorescence a rusty tomentellous panicle |
| 19' | Inflorescence a spike or fascicle. |
| 20 | Leaves 8-21 cm. Reticulation faintly prominent. Inflorescence a fascicle. Bracts persistent. Fruits 10-12 mm long. Seeds straight. Stone different from the following. |
| 20' | Leaves -15-45 cm. Reticulation much prominent. Inflorescence a (basally branched) spike (a cone in bud). Bracts caducous. Fruits 8-10 mm long. Seeds not straight. Stone with a transverse constriction at one side |
| 21 | Leaves distichous. |
| 21' | Leaves spirally arranged. |
| 22 | Fruits ampulliform. Inflorescence a fascicle. Bracts persistent. Stone ampulliform. |
| 22' | Fruits not ampulliform. Inflorescence not a fascicle. Bracts caducous. Stone not ampulliform. |
| 23 | Upper side of leaves hairy |
| 23' | Upper side of leaves glabrous. |
| 24 | Bracts persistent. |
| 24' | Bracts caducous. |
| 25 | Fruits 10-12 mm long and 5-6 mm broad |
| 25' | Fruits to c. 10 mm long. |
| 26 | Stone ellipsoid. Leaf margin (and petiole) beset with closely spaced glands. |
| 26' | Stone ampulliform. Fruits 5-7 mm. |
| 27 | Nerves more than 10 pairs. Inflorescence a (basally branched) spike. |
| 27' | Nerves less than 10 pairs. Inflorescence a fascicle |
| 28 | Inflorescence not a spike. |
| 28' | Inflorescence a (basally branched) spike or a cone. |
| 29 | Inflorescence a panicle. Seeds not straight |
| 29' | Inflorescence a (basally branched) raceme. |
| 30 | Angle of leaf base c. 90° |
| 30' | Angle of leaf base 20-60° |
| 31 | Fruits to c. 10 mm long; mesocarp fleshy (shrivelled when dry) or thin, coriaceous. |
| 31' | Fruits 22-40 mm long; mesocarp woody or corky. |
| 32 | Leaves longer than 15 cm. Fruits 1-celled. Angle of leaf base 20-40°. Stone with low ridges and a depression or transverse groove near the base. Seeds not straight. |
| 32' | Leaves 6-14 cm. Fruits 3-celled. Angle of leaf base c. 90°. Stone with low not interrupted ridges or grooves or brain-like grooved. Seeds straight |
| 33 | Nerves 10-13 pairs |
| 33' | Nerves 6-9 pairs |
