| 1 | Leaves 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. |
| 2 | Leaves 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 |
| 3 | Perianth 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. |
| 4 | Androecium 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 |
| 5 | Leaves 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 |
| 6 | Twigs 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 |
| 7 | Androecium 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) |
| 8 | Inflorescences 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 |
| 9 | Androecium 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 |
| 10 | Leaves with dots beneath (lens!). Twigs angular or ridged |
| 10' | Leaves without dots. Twigs terete, angular, or winged |
| 11 | Perianth 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 |
| 12 | Perianth 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 |
| 13 | Anthers 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) |
| 14 | Anthers 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 |
| 15 | Twigs angular or winged. Perianth 4 mm wide, glabrous. — Philippines |
| 15' | Twigs terete. Perianth 2.5-3 mm wide |
| 16 | Pedicel 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) |
| 17 | Flower 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 |
| 18 | Twigs 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. |
| 19 | Perianth 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 |
| 20 | Leaves 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 |
| 21 | Inflorescences 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 |
| 22 | Buds 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 |
| 23 | Inflorescences 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 |
| 24 | Buds 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 |
| 25 | Buds 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 |
| 26 | Pedicel and bud together 10-12 mm long |
| 26' | Pedicel and bud together 5 mm long |
| 27 | Buds 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.] |
| 28 | Androphore (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 |
| 29 | Buds ± 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 |
| 30 | Bud 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 |
| 31 | Buds glabrous. — A variable species |
| 31' | Buds minutely pubescent, or in H. corrugata (at 1200-1900 m altitude) early glabrescent |
| 32 | Leaves ± 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 |
| 33 | Pedicel 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 |
| 34 | Pedicel 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 |
| 35 | Inflorescences 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 |
| 36 | Buds ± 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 |
| 37 | Buds (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 |
| 38 | Buds 1.2-1.9 mm diam. — A variable species |
| 38' | Buds 2-3.3 mm diam. — A variable species |
| 39 | Buds (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 |
| 40 | Buds 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 |
| 41 | Buds 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 |
| 42 | Buds 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 |
| 43 | Leaves 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 |
| 44 | Leaves ± 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 |
| 45 | Leaves with dots beneath (lens!) |
| 45' | Leaves without dots |
| 46 | Bark 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. |
| 47 | Bark 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 |
| 48 | Twigs ridged or short-winged. — Sumatra |
| 48' | Twigs terete, neither ridged nor winged |
| 49 | Leaf pubescent beneath. — Sumatra, Peninsular Malaysia |
| 49' | Leaf glabrous beneath. — Borneo |
| 50 | Pedicel 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 |
| 51 | Androphore ± absent. Leaves blackish brown. — Borneo. |
| 51' | Androphore 0.3-0.4 mm long. Leaves bright brown. — Peninsular Thailand, Sumatra, Peninsular Malaysia |
| 52 | Buds ± 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) |
| 53 | Buds 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 |
| 54 | Twigs 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.] |
| 55 | Buds 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) |
| 56 | Apical 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 |
| 57 | Leaves 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 |
| 58 | Leaves 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 |
| 59 | Leaves not scabrous above |
| 59' | Leaves scabrous above |
| 60 | Leaves with dots and/or dashes beneath, obscured by hairs or not (lens!). |
| 60' | Leaves without dots or dashes beneath |
| 61 | Buds 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 |
| 62 | Twigs 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 |
| 63 | Buds 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 |
| 64 | Buds 1 mm diam., with persistent indumentum or late glabrescent |
| 64' | Buds 1-2.5 mm diam., glabrous or glabrescent |
| 65 | Pedicel not or indistinctly articulated (this character not quite clear in H. gracilis and H. rufo-lanata) |
| 65' | Pedicel articulated |
| 66 | Upper 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 |
| 67 | Twigs 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. |
| 68 | Leaves 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 |
| 69 | Twigs at apex pale, greyish or straw, contrasting with the dark brown petiole |
| 69' | Twigs at apex (dark) brown, not contrasting with the petiole |
| 70 | Androecium 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 |
| 71 | Leaves 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 |
| 72 | Pedicel 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 |
| 73 | Buds (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 |
| 74 | Twigs 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 |
| 75 | Buds cleft nearly to the base. — New Guinea |
| 75' | Buds cleft 1/2-2/3. — West Malesia |
| 76 | Buds 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 |
| 77 | Buds 2.5 mm diam., pubescent. — N Sumatra |
| 77' | Buds 1-1.5 mm diam., glabrous. — S Peninsular Thailand, Sumatra, Peninsular Malaysia, Borneo |
| 78 | Buds 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 |
| 79 | Inflorescences 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. |
| 80 | Androecium 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!) |
| 81 | Leaves 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. |
| 82 | Twigs 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) |
| 83 | Leaves 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 |
| 84 | Twigs 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. |
| 85 | Leaf 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 |
| 86 | Twigs 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 |
| 87 | Leaves 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) |
| 88 | Leaf 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 |
| 89 | Buds 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 |
| 90 | Buds 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 |
| 91 | Leaves with dots beneath (lens!) |
| 91' | Leaves without dots beneath. [Pedicel not articulated.] |
| 92 | Pedicel 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 |
| 93 | Buds 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 |
| 94 | Androecium 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 |
| 95 | Leaves 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 |
| 96 | Leaves with dots beneath |
| 96' | Leaves without dots beneath (dots should not be confused with smaller, blackish points) |
| 97 | Twigs 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 |
| 98 | Buds cleft 3/4-4/5; anthers 7-11 |
| 98' | Buds cleft 1/3-2/3; anthers 9-20. — Sumatra, Java |
| 99 | Anthers 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 |
| 100 | Buds 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 |
| 101 | Buds ± 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 |
| 102 | Perianth 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.] |
| 103 | Bark 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. |
| 104 | Pedicel 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 |
| 105 | Pedicel (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 |
| 106 | Buds cleft c. 1/2 |
| 106' | Buds cleft 2/3-4/5 |
