| 1 | Papillae on the lower leaf surface indistinct or obscure. Fertile anthers 1-1¼ mm long. Fruits glabrous; hypocarp pulvinate or obconical-cylindric |
| 1' | Papillae on lower leaf surface usually distinct. |
| 2 | Leaves very narrow, ½-1½ cm wide |
| 2' | Leaves much broader, usually more than 5 cm wide. |
| 3 | Flower-buds oblong. Fertile anthers (1-)1¼-1¼ mm. Fruits almost glabrous; hypocarp funnel- shaped or short-cupular |
| 3' | Flower-buds subglobose or globose. Fertile anthers ⅔-¾ mm long. Fruits hairy; hypocarp pulvinate or obconical. |
| 4 | Petals valvate. Fruit apex truncate, or slightly concave. |
| 4' | Petals imbricate. Fruit apex obtuse or rounded. |
| 5 | Leaves (17-)21-46(-60) by (8-)13-20 cm, lower surface pubescent. |
| 5' | Leaves smaller, 6-22 by 3½-8½ cm, lower surface glabrous, sometimes sparsely puberulous, glabrescent |
| 6 | Petals sericeous outside. Fruits velutinous |
| 6' | Petals puberulous or sparsely puberulous outside. Fruits pubescent or sparsely hairy. |
| 7 | Leaves with 5-10 pairs of nerves. Flower or fruit after falling leaving a distinct stalk 1½-8 mm long. Fruits c. ⅔ cm Ø |
| 7' | Leaves with 10-25 pairs of nerves. Flower or fruit after falling leaving no stalk or an obscure one. |
| 8 | Leaf apex acute, shortly or abruptly acuminate, obtuse, rarely retuse; lower surface densely, sometimes sparsely, tomentose or pubescent, glabrescent, or glabrous. Fruits ¾-l cm Ø |
| 8' | Leaf apex acuminate or subcaudate; lower surface puberulous. Fruits 1½-1¾ cm Ø |
