| 1 | Petals ± straight and flat, completely hairy (Fig. 7). Fruits laterally flattened to 5-cornered to subglobular, wall 6-17 mm thick, with cavities (Fig. 3e-p). Petioles channelled above. Filaments and connectives hairy. Ovaries 2-6-locular |
| 1' | Petals convex or cucullate, glabrous except often for a few apical hairs (Fig. 1). Fruits laterally flattened, wall thin, c. 0.4 mm thick, entire (Fig. 3a-d). Petioles flat above to cylindrical. Filaments and connectives glabrous. Ovaries 2-locular |
| 2 | Inflorescences cauliflorous or terminal. Stamens connate to each other and adnate to pistillode; connective without appendage. Fruits laterally flattened to triangular to square to ± cylindrical in transverse section, broadest basally or apically, usually angular; wall 6-8 mm thick. Stigmas on top of ovary (visible in pistillate flowers and fruits). — Sulawesi to Solomon Islands |
| 2' | Inflorescences terminal. Stamens free from each other and pistillode, connective with short, c. 0.3 mm high appendage. Fruits subglobular to ovoid to angular-subglobular; wall 8-18 mm thick. Stigmas in crater-like opening of ovary. — South East Asia to Sumatra, Borneo and the Philippines |
| 3 | Plants hirsute with c. 1 mm long hairs. Stipules 6-15 mm long, usually with lateral lobes, hairy on both sides, seldom glabrous. Bracts (1.8-)4.5-31 mm long (check especially the basal ones; Fig. 2b). Pistillode with long hairs. Fruits densely hirsute. |
| 3' | Plants subglabrous to hirsute with up to 1 mm long hairs. Stipules 0.8-3 mm long, glabrous inside. Bracts 0.7-2.7 mm long (Fig. 2a). Pistillode glabrous to hairy with short to long hairs. Fruits somewhat hairy |
| 4 | Petals strongly cucullate, as deep as high, apex glabrous. Pistillode glabrous. Fruiting pedicel up to 2.5-4 mm long. Ovary with petaloid imprints. — Sumatra, Java |
| 4' | Petals cucullate, higher than deep, apex with few hairs. Pistillode hairy. Fruiting pedicel up to 12 mm long. Ovary without petaloid imprints. — South East Asia main land, Sumatra, Borneo, Philippines |
