| 1 | Flowers in one cluster or semi-cluster all in about the same stage of development. Synandrium depressed-globose, slightly broader than long. Androphore short, about as long as or shorter than the synandrium. Anthers 4-6. Fruits 4.5-7 cm long. |
| 1' | Flowers in one cluster usually in different stages of development. Synandrium globose or short-ellipsoid, about as broad as long or longer than broad. Androphore about as long as or longer than the synandrium or, in Java, sometimes shorter than the synandrium. Anthers mostly 3-6. Fruits of variable sizes |
| 2 | All male perianths on a plant (3- or) 4-lobed. Anthers 4-6. Leaf buds, twig apex and inflorescences with grey-brown hairs 0.1-0.2 mm long, sometimes glabrescent. Nerves above flat or but little raised. Pericarp 2-10 mm thick. |
| 2' | Male perianths more or less evenly mixed 4- and 5-lobed. Anthers 4. Leaf buds, twig apex and inflorescences with rusty hairs 0.5 mm long, sometimes late glabrescent. Nerves raised above. Pericarp 1.5-3(-4) mm thick |
| 3 | Leaves 8-20 cm long, drying greenish; nerves 7-12 pairs. Inflorescences weak and slender, rather poorly flowered. Fruits 4.5-7 cm long, pericarp 5-8 mm thick, drying brown |
| 3' | Leaves larger, 15-35 cm long, usually drying dark brown; nerves 11-24 pairs. Inflorescences variable. Fruits up to 4.5(-5.5) cm long, pericarp less than 5 mm thick, drying blackish |
