| 1 | Midrib prominent on the upper surface. |
| 1' | Midrib impressed on the upper surface. |
| 2 | Twigs hairy. |
| 2' | Twigs glabrous. |
| 3 | Leaves evenly distributed. Fruits ellipsoid |
| 3' | Leaves crowded towards the end of the twigs. Fruits ovoid |
| 4 | Leaves crowded towards the end of the twigs. Fruits ovoid |
| 4' | Leaves evenly distributed. Fruits ellipsoid |
| 5 | Twigs hairy. |
| 5' | Twigs glabrous. |
| 6 | Leaves distichous. |
| 6' | Leaves spirally arranged. |
| 7 | Inflorescence a raceme or panicle. Fruits ovoid to ellipsoid, 7-12 mm. Bracts caducous. |
| 7' | Inflorescence a fascicle. Fruits ampulliform. Bracts persistent |
| 8 | Upper side of leaves hairy. |
| 8' | Upper side of leaves glabrous. |
| 9 | Angle of leaf base more than 90°. Bracts caducous. Hairs on twigs more than 2 mm long. |
| 9' | Angle of leaf base less than 90°. |
| 10 | Fruits 8-10 mm long. Leaf margin (and petiole) beset with closely spaced glands. |
| 10' | Fruits more than 10 mm long. Leaf margin (and petiole) often glandular but glands not closely spaced |
| 11 | Leaves crowded towards the end of the twigs. Inflorescence a spike. Fruits ovoid, 10-12 mm. |
| 11' | Leaves evenly distributed. |
| 12 | Underside of leaves glabrous. (If leaf margin and petiole beset with closely spaced vesicular glands: 3. S. adenophylla.) |
| 12' | Underside of leaves hairy (or pulverulent, nearly glabrous, in S. adenophylla). |
| 13 | Fruits cylindrical. Inflorescence a fascicle |
| 13' | Fruits ampulliform or ovoid. Inflorescence a spike or a panicle. |
| 14 | Fruits ampulliform. Inflorescence a (basically branched) spike. Seeds not straight. |
| 14' | Fruits ± ovoid. Inflorescence a panicle. Seeds curved |
| 15 | Bracts caducous. |
| 15' | Bracts persistent. |
| 16 | Stone smooth. Fruit 5-8 mm, ellipsoid. |
| 16' | Stone with ridges or grooves. |
| 17 | Fruits 3-celled with 8 high ridges, 22-40 mm |
| 17' | Fruits 1-celled. |
| 18 | Inflorescence a panicle |
| 18' | Inflorescence a (basally branched) spike (a cone in bud) |
| 19 | Fruits more than 13-18 mm long |
| 19' | Fruits to c. 10 mm long. |
| 20 | Stone ellipsoid. Leaf margin (and petiole) beset with closely spaced glands |
| 20' | Stone ampulliform. |
| 21 | Nerves more than 10 pairs. Inflorescence a (basally branched) spike. Seeds not straight. |
| 21' | Nerves 6-8 pairs. Inflorescence a fascicle |
| 22 | Underside of leaves hairy. |
| 22' | Underside of leaves glabrous. |
| 23 | Leaves crowded towards the end of the twigs. Nerves 8-10 pairs. Stone smooth. Inflorescence a spike |
| 23' | Leaves evenly distributed or nerves more than 10 pairs. Stone with ridges or grooves. |
| 24 | Leaves distichous. Inflorescence a raceme or panicle |
| 24' | Leaves spirally arranged. |
| 25 | Nerves less than 10 pairs. Bracts persistent. Fruits 13-18 mm long. Stone with low not interrupted ridges or grooves or brain-like grooved. Seeds straight |
| 25' | Nerves 12-17 pairs. Bracts caducous. Fruits 8-10 mm long. Stone with low ridges and a depression or transverse groove near the base. Seeds not straight |
| 26 | Leaves distichous |
| 26' | Leaves spirally arranged. |
| 27 | Inflorescence terminal |
| 27' | Inflorescence axillary. |
| 28 | Bracts caducous. |
| 28' | Bracts persistent. |
| 29 | Inflorescence a spike. Fruits 25-40 mm |
| 29' | Inflorescence not a spike. Fruits shorter than 25 mm. |
| 30 | Inflorescence a panicle. |
| 30' | Inflorescence a (basally branched) raceme (rarely a cone in bud). |
| 31 | Petiole 7-10 mm |
| 31' | Petiole 10-50 mm |
| 32 | Fruits 3-celled |
| 32' | Fruits 1-celled. |
| 33 | Nerves 5-8 pairs. Terminal buds hairy |
| 33' | Nerves 9-14 pairs. Terminal buds glabrous |
| 34 | Fruits ovoid to cylindrical. |
| 34' | Fruits ampulliform. |
| 35 | Acumen shorter than 5 mm. Apex of leaves rounded or acute |
| 35' | Acumen longer than 5 mm. |
| 36 | Nerves 10-16 pairs. Reticulation coarse. Inflorescence a fascicle. Fruits 7-10 mm long. |
| 36' | Nerves 3-11 pairs. Reticulation fine. Inflorescence a (basally branched) spike. Fruits 13-18 mm long |
| 37 | Petiole 2-9 mm. Inflorescence a raceme or panicle |
| 37' | Petiole 10-15 mm. Inflorescence a spike |
