KEY 1 TO THE GENERA (based primarily on vegetative as well as on flower and fruit characters)

1Terminal pair of pinnae transformed into tendrils. — Lianas or shrubs with climbing branches
1'Terminal pair of pinnae provided with unipinnate leaflets. — Trees, shrubs, or lianas
2Leaves apparently simple, being modified to phyllodes (also cultivated)
2'Leaves uni-or bipinnate
3Leaves unipinnate (cultivated)
3'Leaves bipinnate (unifoliolate leaves with two joints on the leaflet stalk)
4Leaves without extrafloral nectaries on petioles, rachises and pinnae
4'Leaves with extrafloral nectaries on petioles, rachises and/or pinnae
5Stems unarmed
5'Stems armed
6Climber (with leaves sensitive to the touch) (also cultivated)
6'Erect trees or shrubs
7Leaflets IV2 or 2 pairs per pinna, proximal leaflets most often unpaired
7'Leaflets more than 6 pairs per pinna
8Leaflets alternate. Seeds red or partly red (also cultivated)
8'Leaflets opposite
9Juvenile shoots, inflorescence and leaves covered by stellate hairs. Introduced from Brazil
9'Plant without stellate hairs
10Stamens 8. Valves of fruits forming one-seeded segments at maturity, leaving the sutures as an empty frame (cultivated)
10'Stamens numerous. Valves of fruits not forming one-seeded segments at maturity
11Stamens united at the base, bright red or pink at least distally. Fruit with two thickened margins, elastically dehiscing from the apex (cultivated).
11'Stamens free to the base, white. Fruit without thickened margins, not elastically dehiscing from the apex (cultivated)
12Fruit ± separating in individual segments or if central part of fruit separating as one piece, then peduncle not prickly. Stems hairy or bristly (in Malesia)
12'Fruit valves each separating as one unit from a ± persistent replum; peduncle prickly. Stems glabrous (in cultivated species)
13Stems armed
13'Stems unarmed
14Stems armed by a single, recurved prickle from the base of the leaf-scar
14'Stems without a single, recurved prickle
15Short-shoots terminated by spines or composed of many persistent fused stipules and (sometimes) bracts. Fruits erect, oblanceolate and opening from the apex. Neuter or non-functional male flowers at the base of the inflorescence
15'Short-shoots without terminal spines
16Stems armed with recurved prickles at the internodes or prickles paired just below the nodes
16'Stems armed with spinescent stipules
17Stipules recurved and hook-like. Flowers in corymbs
17'Stipules ± straight and erect. Flowers in glomerules or spikes
18Flowers in spikes
18'Flowers in glomerules or umbels
19Fruits chartaceous. Stamens 15 (also cultivated)
19'Fruits drupaceous. Stamens 10
20Leaves with 1 pair of pinnae, each pinna with 1 pair of leaflets (also cultivated)
20'Leaves with more than 2 pairs of leaflets on each pinna
21Flowers heteromorphic within the same inflorescence unit; filaments united in a tube. Pods brown, falling apart in one-seeded indehiscent segments
21'Flowers uniform, filaments free. Pod rarely moniliform and, if so, greyish (also cultivated)
22Pinnae unifoliolate, i.e. with a single leaflet and with two scars on the stalk
22'Pinnae with at least one pair of leaflets
23Aquatic or terrestrial herbs
23'Trees or shrubs
24Stipules subulate. Fruits subsessile, linear, with oblique or longitudinal seeds (cultivated)
24'Stipules ovate to lanceolate, striately veined. Fruits stipitate, narrowly to broadly oblong with seeds ± transverse
25Inflorescences consisting of pedunculate pendulous clavate heads, receptacle enlarging in the fruiting stage (also cultivated)
25'Inflorescences pendulous or not, not consisting of clavate heads, receptacle not enlarging in the fruiting stage
26Leaflets alternate, except perhaps for the distal two (always more than two alternate pairs per pinna)
26'Leaflets opposite, if only two pairs of leaflets per pinna the proximal pair rarely alternate
27Leaflets petiolulate. Flowers in pedunculate axillary corymbs. Pods curved into a circle or contorted, reddish inside, dehiscent
27'Leaflets sessile. Flowers in compound inflorescences. Pods straight, not reddish inside, usually indehiscent (or tardily dehiscent)
28Specimen flowering
28'Specimen in fruit
29Stamens 10, free
29'Stamens more than 10
30Anther-glands absent
30'Anther-glands present
31Leaflets broadly elliptic(-lanceolate), 3.8-14 by 2.4-6.7 cm. Anthers glabrous (cultivated)
31'Leaflets linear or linear-oblong, 0.6-2.1 by 0.15-0.5 cm. Anthers hairy (also cultivated)
32Leaflets broadly elliptic(-lanceolate), 3.8-14 by 2.4-6.7 cm
32'Leaflets oblong
33Filaments free (cultivated)
33'Filaments united, forming a tube (tribe Ingeae)
34Flowers uniform within an inflorescence unit, i.e. without: an enlarged central flower with an intrastaminal disc
34'Flowers heteromorphic within an inflorescence unit
35Inflorescences simple
35'Inflorescences compound
36Flowers subtended by bracts with an extrafloral nectary.
36'Flowers subtended by eglandular bracts or bracts inconspicuous
37Inflorescence pendulous
37'Inflorescence erect
38Leaflets sessile
38'Leaflets stalked
39Stipules present in the mature plant.
39'Stipules absent in the mature plant
40Flowers pedicellate
40'Flowers sessile
41Ovary solitary
41'Ovaries 3-5 per flower
42Flowers subtended by bracts with an extrafloral nectary.
42'Flowers not subtended by persistent bracts with nectaries
43Basic unit of inflorescence a raceme or a spike
43'Basic unit of inflorescence a glomerule, corymb or an umbel
44Stipules visible in the mature plant, basic unit of inflorescence a raceme
44'Stipules not visible in the mature plant
45Basic unit of inflorescence a spike (flowers sessile)
45'Basic unit of inflorescence a raceme (flowers pedicellate)
46Flowers pedicellate
46'Flowers sessile
47Leaflets sessile
47'Leaflets petiolulate
48Main vein of leaflets diagonal or nearly so. Glomerules of 2 or 3 flowers
48'Main vein of leaflets not diagonal. Glomerules of more than 10 flowers
49Petiolar gland bowl-shaped, margin with sharp rim
49'Petiolar gland circular to elliptic, raised or flat, without sharp rim
50Calyx 1-1.5 mm, puberulous to tomentose all over
50'Calyx c. 2.5 mm, pubescent especially at the apex of the lobes (cultivated)
51Staminal tube equalling or shorter than the corolla tube
51'Staminal tube longer than the corolla tube, sometimes longer than the corolla
52Ovary stipitate
52'Ovary sessile (not known in Archidendron novoguineense)
53Corolla 15 mm long. Leaves with 1 or 2 pairs of pinnae
53'Corolla up to 7(-8) mm long. Leaves with (2-)3-6 pairs of pinnae (also cultivated)
54Central flower with 7 or 8 perianth segments (also cultivated).
54'Central flower with 5 perianth segments (also cultivated).
55Seeds without pleurogram
55'Seeds with pleurogram
56Pods usually spirally contorted, reddish orange especially on the inner surface with contrasting bluish black seeds, if straight then turgid with disc-like or bitruncate seeds
56'Pods (not known mature in Malesian species) straight and flattened, brownish. Seeds presumably brown, strongly flattened, coin-like, with a narrow wing
57Infructescence unit a spike or a raceme (i.e. rachis prolonged with spaced, scattered scars of fallen flowers)
57'Infructescence unit a glomerule or a corymb (i.e. rachis short, with closely set scars of the fallen flowers)
58Endocarp forming one-seeded envelopes
58'Endocarp not forming one-seeded envelopes
59Seeds with horseshoe-shaped, double pleurogram on each side
59'Seeds with a single pleurogram on each side
60Fruits splitting along both margins for a short distance to let the seeds escape, but not fully opening; with two wings
60'Fruits either indehiscent or fully dehiscent, not winged
61Fruits almost moniliform, 5-8 mm wide; leaflets very small, 0.5-0.75 mm wide (cultivated)
61'Fruits not moniliform; fruits and leaflets larger
62Fruits internally segmented by septae formed by the endocarp, indehiscent.
62'Fruits not internally segmented, dehiscent or indehiscent
63Fruits ± straight; seeds uniserially arranged, set in a brownish pulp (also cultivated)
63'Fruits curved in a flat plane into a complete circle; seeds biseriate, without pulp (cultivated)
64Pods woody, formed as a boomerang (cultivated)
64'Pods membranous to coriaceous, oblong
65Seeds transverse, endosperm absent. Endocarp not ridged within.
65'Seeds arranged obliquely, endosperm present. Fruit valves ridged within