| 1 | Leaf blade 3-5-foliolate (sometimes simple in juvenile stages) |
| 1' | Leaf blade simple (unlobed or lobed) |
| 2 | Plant (sub)annual; monoecious; diurnal. Probract absent. Male bracts 1(-2) mm long, mostly fugacious. Corolla 20(-30) mm diameter. Seeds compressed, pale, with coarsely undulate edge. [Fruit small, ovoid, or long-cylindrical in cultivated var. anguina.] |
| 2' | Plant (sub)perennial; monoecious or dioecious; largely nocturnal. Male bracts 5 mm long or more. Corolla 30 mm diam. or more. Seeds compressed (tumid in T. pilosa), not with undulate edge |
| 3 | Entire portion of petal narrowly elliptic. Seeds tumid (barrel-shaped or (sub)fusiform) (Fig. 91b) |
| 3' | Entire portion of petal broader, ± obovate (apex ± truncate). Seeds compressed |
| 4 | Male bracts c. 20 mm long, entire. Fruit depressed globose; [seeds embedded in green-black pulp, (narrowly) elliptic, chisel-shaped pointed at base. Leaf blade ± 5-angular.] |
| 4' | Male bracts longer or shorter, usually dentate. Fruit subglobose or ellipsoid |
| 5 | Male bracts 40-50 mm long, entire or shallowly lobed. Fruit pulp green-black. Seeds elliptic, rounded at both ends |
| 5' | Male bracts smaller, dentate (sometimes only at very apex), or bracts much smaller. Fruit subglobose (T. laeoica, p.p.) or (narrowly) ellipsoid; pulp not green-black; seeds various, usually densely packed. Leaf blade of various shape, unlobed or (deeply) lobed. [Old peduncles and/or pedicels often persistent, straw-like. Sect. Edulis (see note at the end of this key).] |
| 6 | Plant with fruit (or female flowers) (fruit not known in T. dieniensis, T. pulleana) |
| 6' | Plant with male flowers (male flowers not known in T. dentifera) |
| 7 | Leaf blade entire or lobed, broadly ovate or circular in outline |
| 7' | Leaf blade entire, ovate-hastate or triangular in outline |
| 8 | Leaf blade entire. Young twig apices minutely sparsely hairy, early glabrescent. Seeds not truncate or but faintly notched at apex, cuneate at base. — Papua New Guinea (Woodlark Is., Bougainville Is.), and western Pacific |
| 8' | Leaf blade entire or (deeply) lobed. Young twig apices and male inflorescences hairy. Seeds truncate or notched at apex. — Whole of New Guinea |
| 9 | Leaf blade often scabrous above, short hairy or glabrescent beneath |
| 9' | Leaf blade glabrous, not scabrous, above, glabrous beneath (densely brown hairy in T. edulis var. septemloba) |
| 10 | Plant delicate. Leaf blade membranous, margin entire |
| 10' | Plant stouter. Leaf blade various, margin (very) finely or coarsely dentate |
| 11 | Petiole hairy, at least in apical part near the base of the blade |
| 11' | Petiole glabrous |
| 12 | Plant from montane area, 1700-2500 m altitude. Blade base cordate |
| 12' | Plant from lowland or lower montane area, up to 1500 m altitude. Blade base truncate or subhastate |
| 13 | Margin of leaf blade dentate, usually with some prickly teeth towards the base only. Blade base truncate or with shallow sinus |
| 13' | Margin of leaf blade dentate with minute teeth only. Blade base with deep sinus |
| 14 | Inflorescences (and flowers) densely hairy |
| 14' | Inflorescences (sub)glabrous (glabrescent) |
| 15 | Hairs of inflorescences and flowers woolly, ± curly, dark brown, more than 2 mm long |
| 15' | Hairs of inflorescences and flowers ± straight, light brown, 1-2 mm long |
| 16 | Leaf blade (narrowly) ovate or subhastate, unlobed, (sub)glabrous, not scabrous |
| 16' | Leaf blade ovate, unlobed or 3-lobed, hairy or glabrescent, scabrous above |
| 17 | Plant delicate. Leaf blade membranous, ovate, margin entire. Bracts about 10 mm long |
| 17' | Plant stouter. Leaf blade chartaceous or coriaceous, ± hastate, margin usually ± dentate. Bracts 10 mm long or more |
| 18 | Rachis 3-5 mm thick. Bracts 30-45 mm long. — Montane at 1500-2000 m |
| 18' | Rachis c. 2 mm thick. Bracts smaller |
| 19 | Leaf blade (sub)coriaceous, margin usually with some prickles towards the base. Petiole glabrous. Leafy stem and rachis ± zigzag. Bracts 8-13 mm long |
| 19' | Leaf blade chartaceous, margin remotely (minutely) dentate. Petiole hairy or late glabrescent. Leafy stem and rachis straight. Bracts 8-20 mm long |
