1Leaves deeply 3-lobed
1'Leaves not deeply lobed, margin entire, toothed or only slightly lobed.
2Leaf-margin irregularly toothed (Taiwan)
2'Leaf-margin entire or slightly lobed.
3Leaves very narrow, 0.4-2 cm broad (Australia)
3'Leaves broader.
4Leaves hairy (sometimes sparsely) beneath.
4'Leaves glabrous beneath.
5Leaves sagittate to hastate (China, Vietnam)
5'Leaves ± ovate.
6Leaves puberulous above, tomentellous or rather densely puberulous beneath (SE. Asia, S. China, Hongkong, Hainan)
6'Leaves glabrous above.
7Fine reticulation not or scarcely visible on both surfaces, which dry minutely wrinkled; uncinate hairs absent from main nerves beneath
7'Fine reticulation raised on both surfaces; some uncinate hairs present on main nerves beneath
8Leaves narrowly elliptic to elliptic.
8'Leaves ± ovate, rotund or triangular.
9Leaf-base sagittate
9'Leaf-base rounded or subtruncate
10Inflorescences appearing when plant is leafless.
10'Inflorescences appearing together with leaves.
11Stems strongly tuberculate (tubercles may be little-developed on young stems). Leaves lacking hollow domatia in basal nerve-axils. Petals usually 3. Endocarp 11-13 mm long
11'Stems not tuberculate; petals 6.
12Leaves with a pair of hollow domatia on lower surface in basal nerve-axils. Petals usually 6. Endocarp 7-9 mm long
12'Leaves with glandular patches on lower surface in basal nerve-axils, ± triangular with sides straight or sometimes concave towards base. Endocarp shortly pointed at both ends (Australia)
13Leaves 18-28 by 11-23 cm, thinly coriaceous, lacking domatia or glandular patches in basal nerve-axils. Endocarp 1.7-2.4 cm long, surface very smooth, whitish
13'Leaves smaller and thinner, sometimes with domatia or glandular patches in basal nerve-axils. Endocarps not as above.
14Leaves drying matt and minutely wrinkled, fine reticulation not or scarcely visible on either surface, main nerves usually impressed on upper surface. Petals unguiculate, apically subreniform and markedly thickened. Endocarp thinly crustaceous, broadly elliptic in outline, 7-8 mm long, surface smooth or obscurely tuberculate
14'Characters not combined as above.
15Inflorescences with lateral branches, at least towards base. Leaves with very fine, raised reticulation, glandular patches present in basal nerve-axils. Flower-pedicels 5-10 mm. Endocarps 10-12 mm long, strongly tuberculate
15'Inflorescences unbranched.
16Flowers in sessile clusters; inflorescences sometimes zigzag. Endocarps 3.5-4.5 cm long.
16'Flowers pedicellate; inflorescences always straight. Endocarps up to 2.5 cm long.
17Sepals subequal
17'Sepals unequal, the outer 3 much smaller than the inner 3
18Leaves with a pair of domatia in basal nerve-axils. Endocarp 2-2.5 cm long, the surface bearing scattered spinules
18'Leaves with glandular patches or domatia (rarely neither) in basal nerve-axils. Endocarp 6-8 mm long, pointed at both ends.
19Leaves with domatia usually present in basal nerve-axils (replaced by glandular patches in New Guinea). Flower-pedicels 8-12 mm. Outer sepals much smaller than inner sepals
19'Leaves with glandular patches in basal nerve-axils. Flower-pedicels 1-5 mm.
20Male inflorescences 4-7 cm long; male flower-pedicels 1-2.5 mm. Drupes borne on a ± subglobose or shortly 3-branched carpophore, 1.5-2 mm long (Australia)
20'Male inflorescences (5—)7—15 cm long; male flower-pedicels 4-5 mm. Drupes borne on a columnar carpophore, 4-5 mm long