Key to the Species of New Guinea (and the Solomon Islands)



List of spot-characters


Key to all New Guinean species




    This key has three parts, because the identification of the New Guinean species is very difficult. Part one (spot characters) lists a few characters characteristic for some species. The second key is only for the hermaphroditic species, and the last key for all New Guinean species.


List of spot-characters


Ovary and fruit lamellate (click picture)

31. A. lamellata

Leaf beneath scattered with numerous black disc-like glands, often found in swampy area

33. A. ledermanniana

Petiole > 30 mm long, leaves large, 1734 cm long, shiny

50. A. praegrandifolia

Petiole 38 mm long, often entirely pulvinate

10. A. brevicaudata

48. A. parvula

57. A. sclerophylla





Ovary 2-locular (sometimes 2- and 3-locular). Fruit (narrowly) ovoid to fusiform. Papua New Guinea



Ovary 3-locular. Fruit (sub)globose. Bougainville

28. A. heterodoxa


Stipules present in young stages, oblique to slightly falcate. Leaf: apex acute to acuminate. Stamens 2 or 3, not exserted; ovary narrowly ovoid. Fruits narrowly ellipsoid to fusiform, 1619 by 69 mm



Stipules early caducous. Leaf: apex acuminate to cuspidate. Stamens 4 (or 5), exserted; ovary ovoid. Fruits ellipsoid to ovoid, 813 by 813 mm

27. A. hermaphrodita


Petiole 38 mm long, often entirely pulvinate. Sepals narrowly ovate; stamens 1.22.5 mm long

10. A. brevicaudata


Petiole 1126 mm long, pulvinate at base and apex, lower pulvinus often indistinct. Sepals ovate; stamens (?young) 0.50.8 mm long

18. A. egregia


Key to all New Guinean species



Nerves 510 pairs



Nerves 1017 pairs



Petioles 38 mm long, often entirely pulvinate



Petioles 528 mm long, pulvinate at base and apex



Staminate inflorescences (as far as known) 510 mm long; anthers 0.40.5 mm long. Bracts of staminate and pistillate inflorescences inconspicuous, 0.51.5 mm long. Ovary and fruit ovoid to ellipsoid. Fruits 810 mm long, not beaked. Petioles 25 mm long. Leaves 2.55 by 12 cm 



Staminate inflorescences 1126 mm long; anthers 0.60.8 mm long. Bracts of staminate and pistillate inflorescences conspicuous, 1.32.5 mm long. Ovary and fruit narrowly ovoid to narrowly ellipsoid. Fruits 1619 mm long, beaked. Petioles 38 mm long. Leaves 39.5 by 14 cm. Pistillate specimens sometimes with stamens

10. A. brevicaudata


Stipules mostly early caducous. Leaves elliptic to obovate, apex acute to acuminate; nerves 57 pairs

48. A. parvula


Stipules mostly shortly persistent. Leaves (narrowly) elliptic, apex acuminate to cuspidate; nerves 710 pairs

57. A. sclerophylla


Branchlets densely to sparsely tomentose. Leaves above at least on midrib (sparsely) tomentose, beneath (sparsely) tomentose



Branchlets sparsely puberulous to glabrous. Leaves glabrous or only sparsely puberulous beneath



Nerves 710 pairs. Ovary often 2- or 3-locular. Staminate inflorescences 715 mm long, 12 mm diameter. Pistillate pedicel 0.51 mm long. Fruiting pedicel 14 mm long



Nerves 915 pairs. Ovary mostly 3-locular, seldom 4-locular. Staminate inflorescences 992 mm long, 1.55 mm diameter. Pistillate pedicel 0.54 mm long. Fruiting pedicel 39 mm long



Leaves above only midrib tomentose. Pistillate pedicel and ovary tomentose. Fruits ellipsoid, very sparsely puberulous; column at base hairy. Altitude low to 600 m

2. A. annulata


Leaves above midrib and lamina (sparsely) tomentose. Pistillate pedicel and ovary densely tomentose. Fruits ovoid, patchy tomentose; column glabrous. Altitude 13001700 m

54. A. reticulata


Dried leaf: dots distinct; disc-like glands absent or few scattered along the margin; if regularly scattered along the margin then leaf apex cuspidate to caudate. Staminate inflorescences with distinctly interrupted glomerules throughout the rachis or glomerules continuously set, indistinct. Pistillate flowers and fruits 3-locular, fruits ovoid to globose, sometimes slightly lobed (A. nigropunctata), or 2-locular and (broadly) ellipsoid (A. misimana), or hermaphroditic flowers and fruits with withered stamens



Dried leaf: dots indistinct; disc-like glands many scattered along the margin or over the lamina or at base only; if indistinct or only few scattered along the margin then inflorescences subglabrous. Staminate inflorescences (as far as known) with glomerules at base interrupted at 0.51 mm, continuous apically. Pistillate flowers and fruits 2-locular (A. egregia), narrowly ovoid or narrowly ellipsoid to fusiform, or 3-locular, ovoid to globose, not lobed



Inflorescences with hermaphroditic flowers; fruits with withered stamens. Altitude > 1000 m



Staminate and pistillate inflorescences separate; stamens never present in pistillate flowers or fruits. Altitude up to 600 m



Ovary mostly 2-locular (sometimes 2- and 3-locular); stigmas 1.52.5 mm long; pedicel 13.5 mm long. Fruit ellipsoid to (narrowly) ovoid; pedicel 27 mm long; pericarp 0.30.5 mm thick. Papua New Guinea

27. A. hermaphrodita


Ovary mostly 3-locular (sometimes 2-locular); stigmas 0.81.2 mm long; pedicel 0.51 mm long. Fruit (sub)globose; pedicel 35 mm long; pericarp 0.51 mm thick. Fruit. Bougainville

28. A. heterodoxa


Leaf: apex acuminate to cuspidate; dots rather laxly set; disc-like glands occasionally present along the margin. Branchlets, petiole, and midrib beneath glabrous or sparsely puberulous. Staminate inflorescences continuous (click picture). Pistillate flowers and fruits (as far as known) subsessile, very sparsely puberulous to glabrous, mostly 2-locular, seldom 3-locular. Fruits not lobed



Leaf: apex cuspidate to caudate; dots densely set; disc-like glands regularly present along the margin. Branchlets, petiole, and midrib beneath (sparsely) tomentose. Staminate inflorescences interrupted. Pistillate flowers and fruits pedicelled, sparsely sericeous to sparsely puberulous, 3-locular. Fruits slightly lobed

44. A. nigropunctata


Branchlets and leaves completely glabrous. Stipules early caducous. Leaf: base cuneate to attenuate; dots grey. Staminate inflorescences 0.51 mm diameter. Pistillate flowers and fruits unknown. North Papua New Guinea 

34. A. leptochrysandra


Branchlets and midrib of leaves sparsely puberulous. Stipules present in young stages, (slightly) falcate. Leaf: base cordate to cuneate; dots black. Staminate inflorescences 11.5 mm diameter. Pistillate flowers and fruits ovoid, subsessile. Eastern Papuan Islands

41. A. misimana


Leaf: disc-like glands regularly present, along the margin or scattered over the lamina or at base only. Inflorescences sparsely tomentose to puberulous. Staminate inflorescences distinctly (1.59 mm) spaced at base (click picture). Pistillate flower (as far as known) mostly 3-locular, seldom 2-locular; ovary ovoid. Fruit (as far as known) ovoid to subglobose, 812 mm long



Leaf: disc-like glands few, occasionally present along the margin. Inflorescences subglabrous. Staminate inflorescences slightly (0.51 mm) spaced at base (click picture). Pistillate flower 2-locular; ovary narrowly ovoid. Fruit narrowly ellipsoid to fusiform, 1619 mm long

8. A. egregia


Leaf: disc-like glands scattered within the marginal vein arches, throughout the lamina or at the base only



Leaf: disc-like glands scattered along the margin



Stipules shortly persistent, narrowly ovate, oblique. Leaf: disc-like glands scattered near base only; base cordate to obtuse. Staminate inflorescences: glomerules subglobose, spaced at base, continuous apically. Pistillate flower: pedicel either 36 or 00.5 mm long; ovary sericeous. Fruit beaked, ovoid

13. A. carrii


Stipules early caducous. Leaf: disc-like glands scattered over the lamina; base obtuse to cuneate. Staminate inflorescences unknown. Pistillate flower: pedicel 11.5 mm long; ovary sparsely puberulous. Fruit not beaked, possibly globose

69. A. spec. A


Leaves 6.511 by 2.53.5 cm; nerves 57 pairs. Inflorescences axillary to just below the leaves. Staminate inflorescences (ex descr.) 2040 mm long, stamens hardly exserted, c. 1 mm long. Pistillate inflorescences 0.30.5 mm diameter. Flower: pedicel 0.51.5 mm long; ovary 3-locular, glabrous; stigmas slightly recurved, 11.5 mm. Altitude 10002200 m

21. A. flexuosa


Leaves 1218.5 by 46.5 cm; nerves 711 pairs. Inflorescences mostly on the trunk. Altitude 250300 m. Staminate inflorescences 1969 mm long, stamens exserted, 1.22 mm long. Pistillate inflorescences and flowers unknown

70. A. spec. B


Leaf: disc-like glands absent or present along the margin or only near base



Leaves beneath with scattered black disc-like glands. Staminate inflorescences: glomerules interrupted, stamens exserted. Pistillate inflorescences: flowers laxly set at base of rachis, clustered at apex. Ovary and fruit 2- or 3-locular, sparsely light hairy. Mostly in swamps or swampy areas

33. A. ledermanniana


Leaves subglabrous or only beneath on midrib sparsely tomentose; disc-like glands mostly many, sometimes only few, along the margin. Branchlets sparsely tomentose to subglabrous



Leaves above glabrous or on nerves and lamina sparsely to densely tomentose, beneath sparsely to densely tomentose; disc-like glands absent or few near the base. Branchlets (densely) tomentose, seldom sparsely so



Petiole 942 mm long. Leaves 1234 by 413 cm; apex acuminate; disc-like glands mostly many, along the margin (click picture); dots indistinct or absent. Staminate inflorescences 1469 mm long



Petiole 38 mm long. Leaves 6.514 by 1.54.5 cm; apex cuspidate to caudate; disc-like glands occasionally few, along the margin (click picture); dots distinct. Staminate inflorescences up to 8 mm long. Pistillate inflorescences c. 6 mm long; pistillate flower: pedicel minute; stigma 11.5 mm long. Fruiting pedicel < 0.5 mm long

36. A. longicaudata


Leaves rather leathery, shiny when dry; 1734 by 413 cm. Petiole 1142 mm long. Inflorescences axillary or on the branches; peduncle 03 mm long. Fruits long pedicelled (but pistillate flowers not!) 



Leaves papery, dull when dry; 1218 by 46.5 cm. Petiole 916 mm long. Inflorescences (as far as known) mostly on the trunk, occasionally some axillary; peduncle 417 mm long. Fruits and pistillate flowers unknown

70. A. spec. B


Petiole 1127 mm long. Staminate inflorescences 0.71.5 mm diam., sparsely puberulous; glomerules globose, 11.5 by 11.5 mm, spaced at 15 mm along the rachis; bracts inconspicuous, sparsely puberulous. Pistillate inflorescences 1324 mm long, (sparsely) puberulous, flowers laxly set, pedicel 13 mm long. Fruiting pedicel 211 mm long; fruit ovoid

32. A. laxiflora


Petiole 1842 mm long. Staminate inflorescences 33.5 mm diam., (densely) tomentose; glomerules ellipsoid, 34 by 23 mm, spaced at 0.52 mm at base, continuous apically; bracts conspicuous, tomentose. Pistillate inflorescences 28 mm long, tomentose, flowers densely set, sessile. Fruiting pedicel 917 mm long; fruit globose

50. A. praegrandifolia


Indumentum (densely) tomentose. Leaves not or very slightly bullate; margin (lowly) undulate to (lowly) glandular-crenate, not recurved. Stipules persistent or not. Staminate inflorescences (as far as known) 992 mm long. Pistillate inflorescences (as far as known) 578 mm long, flowers subsessile to pedicelled



Indumentum (densely) hirsute. Leaves slightly bullate; margin (lowly) glandular-dentate, recurved. Stipules persistent. Staminate inflorescences (young) 58 mm long. Pistillate inflorescences 35 mm long, flowers sessile

16. A. decipiens


Nerves 1115 pairs



Nerves 912 pairs



Leaves (sparsely) tomentose above, glabrescent; disc-like glands occasionally present at base or along margin, sometimes indistinct. Ovary lowly lobed or not, pedicel 0.51.5 mm long. Fruit lobed or not, 1019 mm broad. Staminate inflorescences (densely) tomentose, slightly interrupted at base only or almost continuous. Petiole 527 mm long. Leaves 731 by 311 cm



Leaves glabrous above; disc-like glands absent. Ovary lamellate (click picture), subsessile. Fruit lamellate (click picture), 1823 mm broad. Staminate inflorescences unknown. Petiole 1137 mm long. Leaves 2032.5 by 6.510 cm

The three species in leads 24 and 25, A. lamellata, A. brassii, and A. papuana, are almost only separable in fruit.

31. A. lamellata


Leaves sparsely tomentose above, glabrescent; dots irregularly set, grey, fading; disc-like glands occasionally present near base only. Inflorescences axillary to just below the leaves, or on the branches. Staminate inflorescences: glomerules spaced at 15 mm at base of rachis, or almost continuous throughout. Pistillate flowers: stigma slightly raised, straight. Fruiting pedicel 37 mm long; fruits ovoid, 1016 by 1016 mm, not lobed; pericarp 1.53 mm thick

9. A. brassii


Leaves (sparsely) tomentose above; dots indistinct; disc-like glands occasionally present along margin. Inflorescences axillary to just below the leaves, not on the branches. Staminate inflorescences: glomerules approximately continuously spaced. Pistillate flowers: stigma raised, recurved. Fruiting pedicel 25 mm long; fruits (broadly) ovoid, 1218 by 1219 mm, slightly lobed; pericarp 12 mm thick

47. A. papuana


Leaf: marginal glands regular, distinct; disc-like glands scattered at base of leaf, sometimes indistinct. Staminate inflorescences with glomerules usually at least at base (slightly) spaced, 969 mm long. Pistillate inflorescences densely to sparsely tomentose, flowers rather densely or rather laxly set along the rachis



Leaf: marginal glands few, indistinct; disc-like glands absent. Staminate inflorescences with continuously set indistinct glomerules, 2792 mm long. Pistillate inflorescences unknown

71. A. spec. C


Staminate inflorescences up to 25 mm diam.; glomerules mostly only spaced at base to almost continuous



Staminate inflorescences up to 1.52.5 mm diam.; glomerules mostly interrupted throughout



Indumentum densely tomentose. Petiole 616 mm long. Leaves 1121 by 49.5 cm; base cordate to rounded; dots irregularly set, fading; disc-like glands occasionally present near base, indistinct. Inflorescences often on the branches. Staminate inflorescences 1669 mm long, 24 mm diam., densely tomentose. Stigma slightly raised, straight. Fruits ovoid, beaked; fruiting pedicel 37 mm long

9. A. brassii


Indumentum tomentose. Petiole 528 mm long. Leaves 926 by 312 cm; base rounded to cuneate; dots densely set, fading; disc-like glands scattered mostly at base, often distinct. Inflorescences axillary or in the axils of fallen leaves. Staminate inflorescences 929 mm long, 35 mm diam., tomentose. Stigma raised, (slightly) recurved. Fruits ovoid to subglobose, not beaked; fruiting pedicel 49 mm long

67. A. vagans


Indumentum sparsely tomentose. Leaf: nervation not sunken. Staminate inflorescences up to 29 mm long. Fruits (sub)globose, long pedicelled

67. A. vagans


Indumentum tomentose. Leaf: nervation often sunken. Staminate inflorescences up to 47 mm long. Fruits unknown

72. A. spec. D