| 1 | Leaves simple. Subg. Meliosma sect. Meliosma |
| 1' | Leaves pinnate. |
| 2 | Petioles 1/5-⅓ the length of the lamina. Panicles mostly axillary or sometimes ramiflorous, sometimes terminal. Inner petals bifid or entire. Endocarps ellipsoid to obovoid, with reticulate to smooth surface, rarely (sub)globose and then smooth, 6-14 cm diam |
| 2' | Petioles ½0-1/5 the length of the lamina. Panicles always terminal. Inner petals always bifid. Endo carps always (sub)globose, always with reticulate surface, 3.5-8 mm diam |
| 3 | Leaf-rachis terminating in 3 (sometimes 2, rarely 1) leaflets. Outer petals widely ovate to orbicular, entire. Endocarps inside with a marginal canal in which runs the vascular bundle connecting pedicels and seed. Sect. Meliosma |
| 3' | Leaf-rachis terminating in 1 (or 2) leaflets of which the short petiolule is always well markedly articulated with the rachis. Outer petals mostly widely reniform, or of irregular shape, mostly wider than long, with ± irregular margin and often emarginate. Endocarps inside without a marginal canal in which runs the vascular bundle, large, wider than 1 cm. Inner petals hardly or not incised at apex. Subg. Kingsboroughia |
| 4 | Leaves 2-5(-6)-jugate; leaflets usually glabrous, sometimes (in Bornean specimens) pubescent beneath, above always with a prominent midrib. Inner petals (1.2—)1.5—2(—3) mm, entire to retuse or slightly bifid at apex. Ovary glabrous. Endocarps 0.7-2 cm diam |
| 4' | Leaves 2-23-jugate; leaflets glabrous or pubescent, midrib usually flat to sulcate above. Inner petals (0.3—)0.5—1(—1.5) mm, always distinctly and rather deeply bifid. Ovary glabrous or pubescent. Endocarps 0.2-1 cm diam. |
| 5 | Leaves (3-)6-18(-23)-jugate, with (10-)20-100 cm long rachis. Leaflets only very rarely with slight pubescence on midrib and nerves above. Panicles large and lax, 0.5-1.5 m, pendulous, usually suddenly bent down at the base, with up to 90 cm long primary side-axes which are never subtended by (small) leaves. |
| 5' | Leaves 2-7(-9)-jugate, rachis up to c. 40(-60) cm. Leaflets usually more or less pubescent on midrib and nerves above, sometimes glabrous. Panicles lax to dense but not very large, 10-50(-70) cm, usually erect, sometimes ± pendulous, but almost never suddenly bent down at the base, with up to 35(-60) cm long side-axes which may be subtended by decrescent leaves. |
| 6 | Leaflets in middle and upper part of the leaf elliptic to lanceolate, very rarely a few linear-lanceolate, index (0.5-)2-5(-7). Petiolules 2-30 mm |
| 6' | Leaflets in middle and upper part of the leaf linear-lanceolate, index 5-10. Lateral petiolules absent or very short, to c. 1 mm |
| 7 | Sepals pubescent. Outer petals glabrous. Leaves 2-3(-4)-jugate. Endocarps 7-8 mm diam. Small trees |
| 7' | Sepals glabrous (rarely with a few hairs), sometimes pubescent but then also outer petals pubescent. Leaves 2-7(-9)-jugate. Endocarps 3-9(-10) mm diam. Small to large trees. |
| 8 | Plants from Malesia except Sumatra and Java |
| 8' | Plants from Sumatra and Java. |
| 9 | Leaflets pubescent at least on midrib and nerves, usually entire. Panicles often with decrescent leaves. Lowland and mountains up to 2500 m |
| 9' | Leaflets (sub)glabrous, usually (obscurely) dentate. Panicles without decrescent leaves. Mountains, 1300-2900 m |
