1Leaves papillose beneath. Male flowers sessile, packed into dense subglobose capi- tula; buds ± obconical, mutually appressed, angular. Perianth 3-lobed, cleft 1/5-2/3. Androecium stalked, anthers 3-5. — Sri Lanka, elsewhere cultivated
1'Leaves not papillose beneath. Male flowers subsessile or usually pedicelled, mutually free or at least not densely clustered; buds variable, not or only somewhat angular. Perianth densely clustered before anthesis in H. sylvestris from E Malesia.
2Leaves in fertile twigs distichous, membranous, usually with whitish marks of irregular shape and size. Perianths globose, 2-lobed, l-1.5(-2) mm diam. Androecium not or hardly laterally compressed; anthers 6-10, for the larger part connate, forming a shallow or deep saucer-shaped column, free apices 0.3 mm, ± incurved; androphore distinct, tapering. — Sri Lanka to Solomon Is. (throughout Malesia), generally coastal-riverine
2'Leaves in fertile twigs distichous (alternate), or dispersed (spirally), or mixed in the same specimen. Leaf of variable consistency, usually without whitish marks. Perianths 2-4-lobed, variable in shape and size. Androecium various; anthers few to many, connate or mutually for some distance free, column variable; if column deeply cup- or saucer-shaped, then anthers at apex free for at least halfway, or deeply inflexed into the cup; androphore various
3Perianth 2-lobed, or sometimes a few flowers in one inflorescence 3- or 4-lobed. — Species mainly from E of Wallace's Line, or the following from W Malesia: H. cras- sifolia (Sumatra, Peninsular Malaysia, Singapore, Borneo), H. penangiana, p.p. (Sumatra), H. sterilis (Borneo), H. sucosa subsp. bifissa (Borneo)
3'Perianth 3- or 4-lobed, or perianth with both 3 and 4 lobes present; sometimes the odd flower in an inflorescence with 2-lobed perianth. — Species from W Malesia, and the following from New Guinea: H. angularis, H. olens, H. sepikensis.
4Androecium not laterally compressed (in cross section ± circular), not longer than wide. — W Malesia
4'Androecium laterally compressed or not; if not or only slightly so then the androecium (including androphore) longer than wide; androecium not or little laterally compressed in odd 3- or 4-lobed flowers. — E Malesia
5Leaves coriaceous, lower surface with inconspicuous, subpersistent, dense indumentum beneath (in Borneo the hairs often deciduous) [dark dots and dashes present.] — Swamp forest on peat or sand
5'Leaves ± membranous, glabrous or early glabrescent beneath. — Not from peat swamp forest
6Twigs 2 mm diam.; bark not pale on drying. Leaves 7-12 cm long, with dots beneath. [Lateral nerves flat and inconspicuous above.]
6'Twigs 2-5(-10) mm diam.; bark pale on drying, often contrasting with the blackish dried petioles. Leaves 14 cm long or more, without dots beneath
7Androecium depressed-globose, largely consisting of anthers; apical hollow flat and shallow
7'Androecium broadly obovoid, consisting of a large sterile basal part at apex with 3 or 4 small anthers (i.e., c. 6 thecae)
8Inflorescences spike-like, unbranched or short-branched, lateral branches to 5 (-10) mm long. Inflorescences, flowers and petioles blackish on drying, usually contrasting with the paler grey-brown twigs. Anthers inflexed. — Moluccas
8'Inflorescences branched, the side branches at least 5 mm long. Inflorescences, flowers, and petioles brown, not contrasting with the colour of the twigs
9Androecium cup- or saucer-shaped, moderately laterally compressed; anthers at one or both sides of the androecium distally distinctly incurved into the central hollow. — E Malesia: Philippines, Sulawesi, Moluccas, NW New Guinea.
9'Androecium laterally flattened or not, the column either 1) solid, 2) broadly but shallowly hollowed only up to c. 1/3, or 3) narrowly slit-like channelled to variable depths; anthers straight or only slightly incurved, never inflexed into the central hollow. — E Malesia: Moluccas, whole of New Guinea
10Leaves with dots beneath (lens!). Twigs angular or ridged
10'Leaves without dots. Twigs terete, angular, or winged
11Perianth together with the pedicel ± pear-shaped, i.e., pedicel tapering. Petiole comparatively long, 1-2.6 cm. Twigs terete, not angular. [Leaf blade (6-)8-22(-25) cm.]
11'Perianth (in lateral view) short-cuneate, rounded, or subtruncate at base; pedicel ± abruptly passing into the perianth, not tapered. Petioles comparatively shorter. Twigs terete or angular
12Perianth cleft about halfway. Anthers connate; androphore short or absent.
12'Perianth cleft to ± 2/3 or more. Anthers mutually free at least in the incurved or inflexed part
13Anthers 18-25, inflexed at both sides into thin-walled laterally compressed androecium cup. Perianth 2.5-4 mm wide. Leaves membranous, matt on drying. — Moluccas
13'Anthers 11-12, inflexed at only one side of the androecium cup; cup thick- and firm-walled. Perianth 2-2.2 mm wide. Leaves chartaceous, ± glossy above. — Philippines (Luzon)
14Anthers free only in the inflexed distal parts, the basal parts connate into a cup- shaped column. Androphore minute, only c. 1/10 of the androecium length.
14'Anthers free for at least 2/3. Androphore longer, c. 1/3 of the androecium. [Twigs generally angular or ridged. Perianth 2-3 mm wide; pedicel glabrous. Anthers all inflexed into the centre of the androecium.] — Moluccas
15Twigs angular or winged. Perianth 4 mm wide, glabrous. — Philippines
15'Twigs terete. Perianth 2.5-3 mm wide
16Pedicel pubescent, shorter than the perianth. Inflorescences densely finely pubescent. Anthers inflexed at both sides of the laterally compressed androecium. — Moluccas (Talaud I.)
16'Pedicel glabrous, longer than the perianth. Inflorescences with sparse hairs less than 0.1 mm long. Anthers inflexed at one side only of the androecium. — Philippines (Samar)
17Flower buds± angular, arranged into dense semi-globose clusters. Androecium much longer than wide, not or slightly laterally compressed. Leaves lanceolate(-linear), usually ± parallel-sided
17'Buds not angular, not densely clustered
18Twigs angular, ridged, or winged, at the apex as well as lower down
18'Twigs not winged, i.e., terete or only somewhat angular or lined at apex.
19Perianth 2-, 3-, or 4-lobed, subspherical, hardly or not laterally compressed, ± glossy, not collapsing on drying. — Papua Barat (Bird's Head)
19'Male perianth predominantly 2-lobed, little or much laterally compressed, matt on drying, slightly or strongly collapsing on drying
20Leaves thinly coriaceous. Pedicel about as long as or longer than the perianth. Buds cleft almost to the base. Hairs of inflorescences and pedicel 0.2-0.3 mm. Anthers 10-14; the column hollow for c. 1/4
20'Leaves membranous. Pedicel shorter than the perianth. Buds cleft to 2/3-3/4. Inflorescences and pedicel almost glabrous, hairs 0.1 mm or less. Anthers (12-) 14-18; column solid or almost so
21Inflorescences 25-35 cm long. Buds ± pear-shaped. Androecium longer than broad; androphore 0.5 mm long or more, about half as long as the anthers or longer
21'Inflorescences 20 cm long or less. Buds of variable shapes. Androecium longer or shorter than broad; androphore short or long
22Buds glabrous (?), 4 by 2 mm. Anthers 10, androphore nearly as long as the anthers. Inflorescences to 25 cm long, glabrescent
22'Buds pubescent, 3 by 3 mm. Anthers 7, androphore about half as long as the anthers. Inflorescences 25-35 cm long, pubescent
23Inflorescences delicate, 2-5(-8) cm long, 1 or 2 (or 3) times branched. — New Guinea, including Aru Is
23'Inflorescences stouter, 5-20 cm long, not or 1-4 times branched (inflorescences of H. sinclairii and H. basifissa from New Guinea sometimes small). — Whole of E Malesia, including Sulawesi; not in the Philippines
24Buds pubescent or late glabrescent, distinctly or only somewhat longer than broad. Anther-bearing part of the androecium much shorter than the elongate club-shaped androphore
24'Buds glabrous or early glabrescent, about as long as or shorter than broad. Androphore much shorter than the anthers
25Buds together with tapering pedicel long pear-shaped. Androphore glabrous.
25'Buds globose or ellipsoid, distinctly marked-off from the slender pedicel. Androphore glabrous or pubescent
26Pedicel and bud together 10-12 mm long
26'Pedicel and bud together 5 mm long
27Buds subglobose or ellipsoid in outline, lobes 0.5-0.8 mm thick. Twig apex, leaf bud, and inflorescences with hairs 0.1-0.2 mm
27'Buds subglobose in outline, lobes 1-1.5 mm thick. Hairs 0.3(-0.4) mm. [Androphore glabrous. Pedicel 3 mm long.]
28Androphore (at least in the lower half) densely pubescent. Pedicel 3-3.5 mm long. Buds cleft c. 1/8 only
28'Androphore glabrous or with a few scattered hairs. Pedicel (3-)4-6.5 mm long. Buds cleft (1/6—)l/4
29Buds ± laterally compressed, ± obtriangular in lateral view, 1.8-3 mm wide, usually ± collapsing on drying. Androphore 0.2-0.5 mm long, shorter than the anthers
29'Buds subglobose, 1-2 mm wide, not or but slightly compressed, wrinkled on drying but not collapsing. Androphore 0.4-0.5 mm long, about half the length of the anthers
30Bud and pedicel together ± pear-shaped; apex broadly rounded in lateral view, the lower (1/4-) 1/3-1/2 tapered and gradually passing into the ± tapered pedicel (these characters not always clear in certain specimens of H. tuberculata). Buds glabrous, pubescent, or glabrescent
30'Buds in lateral view circular, ovate, obovate, elliptic, transversely elliptic, or reni- form; at base short-attenuate, rounded, or truncate, not tapered; pedicel ± slender. Buds hairy (at least at base) or in H. basifissa, H. psilantha, and H. sinclairii glabrous or glabrescent
31Buds glabrous. — A variable species
31'Buds minutely pubescent, or in H. corrugata (at 1200-1900 m altitude) early glabrescent
32Leaves ± lanceolate, 5-16 cm long. Buds cleft only c. 1/6. — Sulawesi
32'Leaves elliptic to lanceolate, 12-30 cm long. Buds cleft about halfway
33Pedicel 1.5-2 mm long; buds 2.3 mm long, thinly pubescent. Anthers 6. — Moluccas; at low altitude
33'Pedicel generally longer; buds 2.5-3.5 mm long. [Vegetatively and sometimes in fruit much resembling H. laevigata.] — New Guinea; at 450-2000 m
34Pedicel stoutish, 2-4 mm long. Buds ± membranous, glabrescent, with or without a few scattered blackish warts. Anthers 8-12
34'Pedicel stout or slender, 2-5 mm long. Buds ± fleshy, pubescent, blackish warts absent. Anthers 5-10
35Inflorescences pubescent to nearly glabrous. Leaf bud and twig at apex with rusty or greyish hairs, 0.1-0.4(-0.5) mm long. Leaves ± glabrescent, or with scattered stellate hairs beneath when younger
35'Inflorescences generally thick-woolly tomentose. Leaf bud and twig at apex with conspicuous, coarse, rusty hairs, (0.3-)0.5-1.5 mm. Leaves with (sub)persistent indumentum, at least on and near the midrib beneath
36Buds ± glabrous, subglobose, 2-3 mm diam., cleft to the base, not collapsing on drying
36'Buds glabrous or hairy, size and shape variable, cleft c. 1/2 to near the base; collapsing on drying or not
37Buds (almost) wholly with ± persistent indumentum, hairs may be very minute and scattered. [Leaves olivaceous-brown, without a reddish tinge. Hairs of leaf bud 0.1-0.2 mm, usually greyish.] —Moluccas, New Guinea, incl. New Britain.
37'Buds (and pedicel) glabrous or glabrescent, at least the upper 4/5. — E Papua New Guinea
38Buds 1.2-1.9 mm diam. — A variable species
38'Buds 2-3.3 mm diam. — A variable species
39Buds (2-)2.5-3.5(-4) mm diam., cleft 1/2-2/3. Leaves 20-40 cm long, olivaceous or brown, not reddish tinged. — Papua New Guinea (Bagabag I., Long I., New Britain, New Ireland)
39'Buds (1-) 1.5-2 mm diam., cleft c. 1/2. Leaves 6-20 cm long, generally with a reddish tinge on drying, especially the midrib and nerves. [Hairs of leaf bud to 0.1 mm long, greyish brown. Buds larger and pedicel pubescent in deviating specimens.] — E Papua New Guinea
40Buds largely pubescent, towards the base thick-walled and coriaceous, the remainder collapsing on drying; both male and female buds opening at apex by small pore-like slit less than 1 mm long. Androecium subellipsoid, mainly consisting of the column with 2 minute anthers at the apex, just below the pore. Leaves coriaceous, ± bullate; with harsh hairs leaving rough thickened bases.
40'Buds glabrous or pubescent, membranous or chartaceous, ± not collapsing on drying, cleft at least c. 1/3. Androecium mainly consisting of 10-16 sessile anthers. Hairs not harsh, not leaving rough thickened bases
41Buds pubescent, cleft 3/4-5/6. Anthers 10-14. Leaves membranous or chartaceous
41'Buds glabrous, except at the very base; cleft c. 1/2 or less. Leaves generally membranous
42Buds subglobose. Anthers 12-16. Leaves oblong(-lanceolate), at apex (acute-)acuminate, not caudate (always?)
42'Buds obovoid or ellipsoid. Anthers 10 (-12). Leaves oblong-lanceolate, at apex caudate
43Leaves in fertile shoots dispersed, i.e. in 3 or more rows along the twigs. Leaf bud proportionally short and broad (about 4 times longer than broad, or less).
43'Leaves in fertile shoots distichous (in rare cases a few on the same plant in 3 rows). Leaf bud generally more slender
44Leaves ± clustered towards the end of the twigs. Leaf bud and inflorescences with hairs 0.5-1 mm long. Bark of older twigs often blackish, flaking. — Borneo (Sarawak, Brunei); sandy soils
44'Leaves clustered or not. Leaf bud and inflorescences with hairs up to 0.2 mm long. Bark of older twigs not or slightly flaking
45Leaves with dots beneath (lens!)
45'Leaves without dots
46Bark of twigs (grey-)brown, not contrasting with the dark colour of the petioles; older bark not flaking. Leaves in 2 or 3 rows. — W, C & S Sumatra, Java
46'Bark pale, grey or yellowish brown, rather contrasting with the petioles; older bark more or less flaking. Leaves in 3-5 rows. — Sumatra (N Aceh); at c. 1300 m.
47Bark of twigs brown, not contrasting with the colour of the petioles
47'Bark of twigs pale, greyish or straw, contrasting with the blackish brown colour of the petioles
48Twigs ridged or short-winged. — Sumatra
48'Twigs terete, neither ridged nor winged
49Leaf pubescent beneath. — Sumatra, Peninsular Malaysia
49'Leaf glabrous beneath. — Borneo
50Pedicel articulated. Androecium with depressed apex, apical hollow broad, either shallow or rather deep, reaching up to nearly halfway the column; androphore largely hidden by the anthers. Leaves mosly distichous, sometimes tristichous. — Sumatra, Peninsular Malaysia,
50'Pedicel mostly not articulated. Androecium not or but slightly depressed, the apical hollow narrow and inconspicuous. Leaves generally in 3-5 rows
51Androphore ± absent. Leaves blackish brown. — Borneo.
51'Androphore 0.3-0.4 mm long. Leaves bright brown. — Peninsular Thailand, Sumatra, Peninsular Malaysia
52Buds ± obconical-obovoid, very leathery, cleft 1/6-1/5 (-1/4) only. Androecium turbinate, anthers 3. — Sumatra
52'Buds of variable shapes, cleft l/5(—1/4) or more. Androecium various, anthers 4 or more (male flowers not known in H. perangusta)
53Buds ellipsoid or obovoid, 3-8 mm long, cleft 1/5—1/4(—1/3). Leaves ± parchmentlike, matt above with finely wrinkled surface (in H. sessilifolia male flowers not known and leaves not so distinctly matt)
53'Buds either 1) ellipsoid or short pear-shaped, 3.5 mm long or less (though sometimes rather large in H. endertii, H. flocculosa, H. majuscula, and H. wallichii), or 2) (depressed) globose; cleft (1 /4—) 1/3—1/2 or more. Texture of leaves variable including coriaceous, never parchment-like and not typically matt above
54Twigs 5-7(-10) mm diam. Leaves 25-70 cm long, indumentum persistent beneath
54'Twigs 3-5 mm diam. Leaves up to 30 cm long, (largely) glabrous beneath, or with some hairs persistent on the midrib. [Male perianth 3-5 mm long.]
55Buds 7-8 mm long, perianth and pedicel glabrous. Petiole 6-15 mm long. — Sumatra, Peninsular Malaysia
55'Male buds not known; female perianth and pedicel pubescent. Petiole almost absent. — Borneo (Sarawak)
56Apical leaf bud with hairs 0.1-0.3 mm. Leaf midrib broad, margin flat
56'Leaf bud with hairs 1 mm long. Leaf midrib above line-shaped, margin (dry) rolled-in
57Leaves to 32 cm long, dark olivaceous. Twigs (yellowish) brown, coarsely striate and tending to crack longitudinally. Inflorescences (almost) glabrous. Pedicel not articulated. Anthers 12-20
57'Leaves up to 24 cm long, fulvous-brown. Twigs brown, finely striate, not cracking. Inflorescences pubescent. Pedicel articulated. Anthers 10-12
58Leaves with (sub)persistent indumentum beneath; in H. gracilis and H. wallichii sometimes hairs vestigial on and near midrib and nerves
58'Leaves glabrous or early glabrescent beneath; in some species often with vestigial hairs on the lower midrib
59Leaves not scabrous above
59'Leaves scabrous above
60Leaves with dots and/or dashes beneath, obscured by hairs or not (lens!).
60'Leaves without dots or dashes beneath
61Buds short pear-shaped, 2-2.5 mm long; pedicel indistinct, 0.3-1 mm long. Leaves thinly pubescent beneath, often ± glabrescent
61'Buds subglobose, 1-1.5 mm diam., pedicel slender, 0.5-1.5 mm long. Leaves with conspicuous indumentum beneath
62Twigs 2-3 mm diam.; leaf blades 7-15 cm long, [lateral nerves 5-9 per side]. — Borneo (Sarawak); sandy soils
62'Twigs 5-8(-14) mm diam.; leaf blades (18-)24-36 cm long. — Sumatra, Peninsular Malaysia
63Buds broadly ellipsoid or obovoid, 2-3 mm long; androecium longer than broad. Pedicel (1.5-)3-4 mm long. Twigs and lower leaf surface with hairs 1.5-2 mm long
63'Buds (depressed) globose, 2.5 mm diameter or less; androecium as broad as or broader than long. Pedicel 3 mm long or less. Twigs and lower leaf surface with hairs to 1.5 mm long
64Buds 1 mm diam., with persistent indumentum or late glabrescent
64'Buds 1-2.5 mm diam., glabrous or glabrescent
65Pedicel not or indistinctly articulated (this character not quite clear in H. gracilis and H. rufo-lanata)
65'Pedicel articulated
66Upper leaf surface dark brown on drying, with venation ± indistinct. — S Peninsular Thailand, Peninsular Malaysia
66'Upper leaf surface olivaceous on drying, venation distinct or not. — Borneo
67Twigs 3.5—7(—13) mm diam. Leaves 10- 45 cm long; venation distinct above; lateral nerves 11 pairs or more. Buds 1.5-2.3 mm diam.; anthers 8 or more.
67'Twigs 3 mm diam. Leaves 12-21 cm long; venation indistinct above; lateral nerves 14-17 pairs; [lower leaf surface with sparse subper si stent hairs, vestigial mainly on nerves and midrib]. Buds 0.6-1 mm diam.; anthers 16-18.
68Leaves 18-45 cm long; lateral nerves 18-25 pairs, sunken above. Buds 1.5-2 mm diam.; anthers 8-10. — Borneo; lowland
68'Leaves smaller, 10-23 cm long; lateral nerves 11-16 pairs, raised above. Buds 2- 2.3 mm diam.; anthers c. 15. — Borneo (Sarawak, Sabah); montane, 900-1400 m
69Twigs at apex pale, greyish or straw, contrasting with the dark brown petiole
69'Twigs at apex (dark) brown, not contrasting with the petiole
70Androecium angular in cross section. Anthers free for the upper half or more. — Borneo; heath forest on sand or peat soil
70'Androecium (sub)circular in cross section. Anthers largely connate
71Leaves chartaceous, bright brown. [Pedicel not articulated. Androecium with small apical hollow.] — Borneo; mostly in heath forest on sandy soils. 12. H. carnosa b. Leaves membranous, (blackish) brown. — Usually growing in forest on richer soils, including sand
72Pedicel articulated. Androecium strongly depressed-globose; apical hollow broad with flattish bottom, to nearly halfway into the androecium. — Sumatra, Peninsular Malaysia
72'Pedicel not articulated. Androecium ellipsoid to slightly depressed-globose; with the apical hollow small and narrow (male flowers not known in H. discolor). — Peninsular Malaysia, Borneo
73Buds (sub)globose, 1.5-2(-2.2) mm long, androecium subglobose or short-ellipsoid, 1 mm long. Leaves distichous or dispersed. — Borneo; up to 700 m. 74 b. Buds ellipsoid, 2-2.4 mm long, androecium ellipsoid, 1.8-2 mm long. Leaves distichous. — Peninsular Malaysia; at c. 1300 m
74Twigs ridged or nearly winged, also in the older wood
74'Twigs not ridged; sometimes twigs faintly ridged, lined, or angular in the apical part only
75Buds cleft nearly to the base. — New Guinea
75'Buds cleft 1/2-2/3. — West Malesia
76Buds slightly broader than long, short-pubescent in the lower half. Androecium slightly broader than long; anthers erect, not incurved
76'Buds subglobose to broadly ellipsoid, glabrous. Androecium longer than broad, ± obovoid, the anthers with apex free and incurved, those of one side of the androecium clasping the others
77Buds 2.5 mm diam., pubescent. — N Sumatra
77'Buds 1-1.5 mm diam., glabrous. — S Peninsular Thailand, Sumatra, Peninsular Malaysia, Borneo
78Buds short pear-shaped, 2(-2.5) mm long, subsessile with the pedicel much shorter than the perianth, 0.3-1 mm long, thickish. Leaves coriaceous, pubescent or glabrescent, with dots and dashes beneath (lens!); lateral nerves flat or sunken above. Twigs hollow
78'Buds variable in shape and size, the pedicel proportionally longer and more slender (buds obovoid with pedicel short in H. glabra var. oviflora). Leaves variable, nerves raised or sunken, dots present or absent. Twigs solid or faintly hollow
79Inflorescences stout, the rachis towards the base 5-8 mm diam. Androecium about as broad as long, triquetrous in cross section, [anthers entirely connate]. — W Borneo
79'Inflorescences large or small, the rachis towards base 4(-4.5) mm thick or less. Androecium triquetrous or circular in cross section. — Whole of W Malesia.
80Androecium 3- or 4-angular in cross section. Anthers ± erect, free for about halfway or more. Buds 1.5(—2) mm diameter or less. Pedicel articulated. Leaves with the lateral nerves raised above; dots absent (H. ridleyana with leaves small, nerves sunken, male buds 1 mm diam.). — Most of W Malesia, not in Sulawesi, rare in the Philippines
80'Androecium in cross section circular, ellipsoid, or subtriangular with rounded angles. Anthers ± curved, almost entirely connate, free apices c. 1/3 or less. Buds (1.3—)1.5 mm diameter or more. Pedicel articulated or not. Leaves with the lateral nerves raised, level, or sunken above; dots present or absent (lens!)
81Leaves 5-16 cm long; midrib and lateral nerves level or sunken above
81'Leaves small or large, 5-28 cm long; midrib and lateral nerves raised above.
82Twigs and inflorescences rather glabrescent. Leaf apex acute or acute-acuminate; nerves faint above. Anthers 4-6. — Peninsular Malaysia, Borneo
82'Twigs late glabrescent, inflorescences with persistent indumentum. Leaf apex blunt; nerves flat or but little raised above, clearly visible. Anthers 9 or 10. — Borneo (Sarawak)
83Leaves early glabrescent beneath, also on the midrib; leaf apex long acute-acuminate. Twigs rather smooth, lower down cracking longitudinally. — Borneo (Brunei)
83'Leaves early glabrescent beneath, but midrib sometimes late glabrescent; leaf apex acute-acuminate. Twigs striate, lower down coarsely striate or finely cracking
84Twigs l-2(-4) mm diam. Leaves 7-18 cm long, thinly membranous to subcharta- ceous; petiole slender, l-1.5(-2) mm diam. Inflorescences delicate, up to 9 cm long; buds 1 mm diam.
84'Twigs 1—5(—8) mm diam. Leaves of variable sizes, chartaceous or coriaceous; the petiole 1.5—4(—8) mm diam. Inflorescences up to 15(-20) cm long; buds 1-2 mm diam.
85Leaf bud with hairs (0. l-)0.2 mm long; twigs at apex and leaves glabrous; inflorescences with sparse stellate hairs 0.2 mm long, glabrescent. Leaves drying to a greyish tinge. Male buds short pear-shaped, tapering into the pedicel
85'Leaf bud, apical part of twig, petiole, midrib beneath and inflorescences with woolly stellate-dendroid hairs (0.2-)0.5 mm long; leaves olivaceous on drying. Male buds globose or depressed-globose
86Twigs and leaves stout, the midrib broad above, at the transition to the petiole at least 3 mm wide. Inflorescences 10-20 cm long. — Borneo; forests on poor soil, including sand and peat
86'Twigs and leaves less robust; midrib above towards the insertion of the petiole less than 3 mm wide. Inflorescences up to 15-20 cm long. — On poor or rich soil
87Leaves 16-28 cm long, leaf base ± rounded or short-attenuate; nerves 16-19 pairs, very prominent above. — Borneo (Sarawak)
87'Leaves 7-28 cm long, base short- to long-attenuate; nerves 6-16 pairs, raised to variable degrees above. [On drying, colour of leaves above and beneath usually much contrasting, generally more so than in the related species.] —Variable, with 3 varieties (based on fruit size). Sumatra, Peninsular Malaysia, whole of Borneo, Philippines (Mindanao, Palawan)
88Leaf bud, apical part of twig, and inflorescences with hairs 0.2 mm long or more (hairs 0.1-0.4 mm long in H. punctata)
88'Leaf bud, apical part of twig, and inflorescences with hairs (0.2-)0.1 mm long or less
89Buds ellipsoid, 2.5-3.5 mm long; androecium longer than broad. [Leaves thick and brittle, apex bluntish; lower surface usually with conspicuous pale golden hair scars (lens!).]
89'Buds (sub)globose; androecium not longer than broad
90Buds 2.5-3 mm diam. (or 1.5 mm in Hallier 624 from W Borneo, see the notes), cleft c. 4/5. — Sumatra
90'Buds (1-)1.2-2.5 mm diam., cleft l/3-2/3(-3/4). — Peninsular Malaysia, Borneo
91Leaves with dots beneath (lens!)
91'Leaves without dots beneath. [Pedicel not articulated.]
92Pedicel articulated. Lateral nerves flat or sunken above. Lower leaf surface cinnamon or chocolate, contrasting with upper surface. — Borneo
92'Pedicel not articulated. Lateral nerves largely raised above. Upper and lower leaf surface not much contrasting. — Peninsular Malaysia
93Buds 2-2.5 mm diam.; androecium sessile, broadly saucer-shaped. Leaves 20-45 cm long. — Lowland forest
93'Buds (1-) 1.4-2.2 mm diam.; androecium (depressed-)globose, with the apical hollow small, concealed by the apices of the anthers. Leaves 4-35 cm long. — Montane forest at 800-2000 m
94Androecium with slender androphore 0.3-0.8 mm long, not hidden by the anthers. Leaves membranous, 9-18 cm long, dark brown, [apex acute-acuminate]
94'Androecium (sub)sessile, androphore absent or up to 0.5 mm, largely hidden by the anthers
95Leaves chartaceous or membranous, to c. 35 cm long, olivaceous-brown; apex acute-acuminate. Inflorescences to 20 cm long. — Borneo (Mt Kinabalu)
95'Leaves coriaceous, 4-14 cm long, blackish; apex obtuse to subacute. Inflorescences 4-16 cm long
96Leaves with dots beneath
96'Leaves without dots beneath (dots should not be confused with smaller, blackish points)
97Twigs 2.5-3(-4) mm diam. Leaves (8-)12 cm long or more. Male buds (subglobose, 1.5-4.2 mm diam
97'Twigs 1.5-2 mm. Leaves 5-12 cm long. Male buds ± ellipsoid or globose, 1.2-1.8 mm long
98Buds cleft 3/4-4/5; anthers 7-11
98'Buds cleft 1/3-2/3; anthers 9-20. — Sumatra, Java
99Anthers 7-9. Dry fruits 4-5 cm long, pericarp 10-20 mm thick. — N Sumatra, Peninsular Malaysia, Borneo
99'Anthers c. 11. Dry fruits 2 cm long, pericarp 1.5 mm thick. — Peninsular Malaysia
100Buds 3-4.2 mm diam.; anthers 15-20. — N & C Sumatra
100'Buds 1.5-2.5 mm diam.; anthers 9-15. — Variable, with 3 varieties. Java, W, C & S Sumatra
101Buds ± ellipsoid; androecium ± obovoid, the apical part of the anthers deeply inflexed into the apical hollow. — New Guinea
101'Buds and androecium of variable shapes; the anthers ± straight or curved, at apex not inflexed. — W and E Malesia, not in New Guinea
102Perianth coriaceous; lobes thick, towards the base (0.3-)0.4-l mm thick. Androecium ellipsoid-obovoid, longer than broad
102'Perianth thinner, lobes at base 0.2-0.3 mm thick. Androecium subglobose, broadly ellipsoid, or obovoid, not or but little longer than broad. [Androphore narrow, only 0.2 mm long. Leaves membranous to chartaceous.]
103Bark of twigs not flaking. Leaves ± membranous
103'Bark of twigs flaking or not. Leaves coriaceous. [Pedicel not articulated. Anthers (3-)4-8; androphore rather broad, tapering, (0.1-)0.2-0.3 mm long.] — Borneo (Sarawak, Sabah); kerangas, montane forest; 800-1550 m.
104Pedicel articulated. Anthers 7-9; androphore rather broad and tapering, 0.2-0.5 mm long. — Sumatra, Peninsular Malaysia; 0-1000 m
104'Pedicel not articulated. Anthers 5 or 6; androphore narrow, 0.1-0.2 mm long, hidden by the anthers. — C Sulawesi; 100-450 m
105Pedicel (1—)1.5—2 mm long, about as long as the perianth. — Peninsular Malaysia, Borneo
105'Pedicel shorter than the perianth, 0.5 mm long. — Sulawesi, Philippines
106Buds cleft c. 1/2
106'Buds cleft 2/3-4/5