| 1 | Twigs densely appressedly pubescent or tomentose. |
| 1' | Twigs glabrous or sparsely fine-hairy. |
| 2 | Fruit ampulliform, with long neck. Ovary 1112 ram high. Calyx lobes c. 1l2mm long. Corolla 2-3 mm. Disk globose or annular, shortly pilose |
| 2' | Fruit ovoid, ellipsoid, or cylindrical. Ovary l½(-2½)mm high. Calyx lobes ½-1(-1½) mm long. Corolla 3-5 mm. Disk 5-glandular, glabrous or sparsely hairy. |
| 3 | Terminal buds glabrous. Secondary veins forming a rather coarse reticulation with the slightly less prominent veins. Inflorescence a many-flowered panicle of racemes, 1-4 cm long. Style shortly pilose for its whole length. |
| 3' | Terminal buds glabrous. Secondary veins prominent, forming a fine reticulation with the faintly prominent tertiary veins. Inflorescence a 1-3-flowered raceme, up to 1 cm. Style pilose only towards its base. |
| 3'' | Terminal buds pubescent. Secondary and tertiary veins much prominent, forming a fine reticulation with the often also prominent quaternary veins. Style glabrous. |
| 4 | Fruit ovoid to cylindrical; stone with shallow lengthwise grooves. Seed ovoid, with small, nearly straight embryo. Disk sparsely hairy. Reticulation beneath very dense. |
| 4' | Fruit ovoid, ellipsoid, or rarely cylindrical; stone with high, interrupted ridges. Seeds ovoid to horse-shoe-shaped, embryo curved, or twice screw-like curved. Disk glabrous, rarely with some hairs. Reticulation beneath either very fine or coarse |
| 5 | Inflorescence a raceme. Ovary 1½ mm. Calyx lobes ½-l mm. Corolla 3-4½ mm. Stamens 20-60. |
| 5' | Inflorescence a spike. Ovary 2½ mm. Calyx lobes c. 1½ mm- Corolla c. 5 mm. Stamens more than 75. |
