| 1 | Leaf laminas coriaceous, tertiary nerves and reticulation obscure; flowers in spikes |
| 1' | Leaf laminas papyraceous, tertiary nerves and reticulation distinct; flowers solitary or in racemes |
| 2 | Leaf laminas elliptic to oblanceolate; fruit globular to ovoid with basal neck |
| 2' | Leaf laminas elliptic to obovate, obovate-elliptic to broadly oval; fruit subglobular to ovoid to obovoid to ellipsoid, without basal neck |
| 3 | Leaf venation slightly areolate, apex short (< 5 mm) acuminate to emarginate; calyx-lobes distinctly or obscurely ciliate, radicle curved |
| 3' | Leaf venation reticulate, apex long (5-16 mm) acuminate; calyx-lobes entire; radicle spirally convolute |
| 4 | Flowers many in racemes |
| 4' | Flower solitary or in 2-5-flowered racemes |
| 5 | Peduncle, pedicel and calyx tube glabrous, pedicel 1-2.5 cm long |
| 5' | Peduncle, pedicel and calyx-tube puberulous to glabrous, pedicel up to 1 cm long |
| 6 | Calyx tube c. 1 cm long, slightly ribbed, staminal tube c. 0.5 cm long, free part of the stamens c. 5 cm long |
| 6' | Calyx tube 1.5-2.5 cm long, smooth; staminal tube 1-1.5 cm long, free part of the stamens c. 3.5 cm long |
