KEY TO THE SPECIES OF MALAY PENINSULA, SUMATRA, BORNEO, AND JAVA

1Rachis of leaves slightly to distinctly winged (Fig. 33b, c)
1'Rachis of leaves not winged (Fig. 33a)
2Jugae (l-)2-7. Upper leaflets elliptic to obovate, lower surface densely greyish papillate, dull; domatia many
2'Jugae 1-4. Upper leaflets elliptic; lower surface smooth (to somewhat papillate), rather shiny; domatia absent or a single
3Wings along rachis narrow, up to 3 mm broad. Apex of leaflets (obtuse to) abruptly acuminate (to cuspidate); lower surface with a convex, raised midrib, hairs obliquely hirsute (to sericeous), domatia many, pockets (to sacs; Fig. 34a, b, d)
3'Wings along rachis always broad, up to 4 mm. Apex of leaflets gradually acuminate to cuspidate; lower surface with a hardly raised, flat midrib, hairs (very) sparsely sericeous, domatia many sacs (Fig. 34c)
4Domatia absent or one sac
4'Domatia two to many sacs to pockets
5Petals 1.8-3.8 mm long; scales with at most a hardly broadened apex (Fig. 36a); crest always present (Fig. 36i-k). Disc interrupted (often almost uninterrupted; Fig. 35). Fruit lobes longer than high and usually sparsely sericeous or lobes about as long as high and glabrous
5'Petals 0.5-4 mm long; scales with a (very) much broadened apex (Fig. 36a); crest usually absent (Fig. 36h). Disc uninterrupted (sometimes with a small slit; Fig. 35a,b). Fruit lobes usually longer than high, glabrous
6Leaves 1-6-jugate. Leaflets ovate (to elliptic), asymmetrical; apex usually gradual ly acuminate to caudate, very apex acute to usually mucronulate
6'Leaves 1-4-jugate. Leaflets elliptic, usually symmetrical; apex abruptly (acuminate to) cuspidate, very apex usually obtuse (to acute), not mucronulate
7Leaflets below smooth, shiny, glabrous. Ovary subhirsute. Fruits glabrous
7'Leaflets below papillate, dull, (slightly) shortly sericeous. Ovary densely hirsute. Fruits (very) sparsely sericeous, glabrescent
8Upper leaflets ovate to obovate; lower surface papillate, hirsute and with many pockets (to sacs) or (slightly) shortly sericeous and with many sacs. Petals (elliptic to) obovate; apex of scales not to hardly broadened (Fig. 36b); crest (usually) present (Fig. 36i-k)
8'Upper leaflets (ovate to) elliptic; lower surface usually smooth, glabrous (to slightly sericeous to subvillose), many sacs. Petals elliptic; scales with a (very) much broadened apex (Fig. 36a); crest usually absent (Fig. 36h).
9Upper leaflets elliptic to obovate; apex (obtuse to) abruptly acuminate (to cuspidate); lower surface (sub)sericeous to hirsute, domatia pockets (to sacs; Fig. 34a-c). Ovary subhirsute. Fruits glabrous
9'Upper leaflets ovate (to elliptic); apex gradually acuminate to cuspidate; lower surface (slightly) shortly sericeous, domatia sacs (Fig. 34b). Ovary densely hirsute. Fruits (very) sparsely sericeous, glabrescent