| 1 | Trees or shrubs, exceptionally lianas. Leaves simple, unifoliolate, (bi)pinnate or digitate. Inflorescences without basal tendrils |
| 1' | Herbaceous or woody climbers. Leaves biternate. Inflorescences with basal tendrils |
| 2 | Leaves simple, unifoliolate, (im)paripinnate or digitate |
| 2' | Leaves bipinnate |
| 3 | Leaves imparipinnate |
| 3' | Leaves simple, unifoliolate, paripinnate or digitate |
| 4 | Pseudo-stipules present. Petals shorter than the sepals |
| 4' | Pseudo-stipules absent. Petals longer than the sepals. |
| 5 | Scale hairs present (rarely only visible in inflorescences), often also with solitary simple hairs. Young parts viscid |
| 5' | Indumentum consisting of solitary, simple hairs, sometimes mixed with stellate hair tufts, or two-branched hairs (Litchi chinensis). Young parts not viscid. N.B.: Lepisanthes fruticosa may have sticky inflorescences (race 'glandulosa' from Borneo). |
| 6 | Leaves paripinnate. Ovules 1 or 2 per locule |
| 6' | Leaves simple. Ovules 2 per locule |
| 7 | Petals present, 5 |
| 7' | Petals absent |
| 8 | Leaf-rachis winged. Disc hairy. Filaments glabrous. Ovary 2-celled Filicium decipiens (p. 754) b. Leaf-rachis not winged. Disc glabrous. Filaments hairy. Ovary 3-celled |
| 9 | Leaflets entire. Sepals connate up to halfway, not petaloid. Stigma lobed |
| 9' | Leaflets subentire to crenate. Sepals free, petaloid. Stigma grooved |
| 10 | Leaves (4-)5-8(-10)-jugate. Filaments of stamens glabrous. Ovules 2 per locule |
| 10' | Leaves (2-)3(-4)-jugate. Filaments of stamens sparsely hairy. Ovules 1 per locule |
| 11 | Leaves paripinnate, if unifoliolate than flowers regular, usually with 5 petals (Lepisanthes senegalensis) or without petals (Glenniea thorellii, Sarcotoechia planitiei) |
| 11' | Leaves digitate, 1-5-foliolate. Flowers zygomorphic, 4-merous |
| 12 | Lower side of leaflets with naked glands |
| 12' | Lower side of leaflets without naked glands |
| 13 | Leaves without pseudo-stipules |
| 13' | Leaves with pseudo-stipules |
| 14 | Sepals free or basally connate, usually narrowly imbricate. Stamens usually 8 (6-10), filaments mostly hairy |
| 14' | Sepals almost totally connate, apert. Stamens 5, filaments glabrous or with few hairs |
| 15 | Ovary 2-, rarely 3-locular, warty |
| 15' | Ovary 3-locular, smooth |
| 16 | Leaves 1- or 2-jugate, exceptionally unifoliolate or 3-jugate. Hairs if present mainly in stellate tufts. Petals absent or present. Disc hairy. |
| 16' | Leaves 1-7-jugate. Hairs if present solitary, simple. Petals present. Disc glabrous or rarely hairy |
| 17 | Leaflets finely dentate to serrate. Ovary with irritant hairs |
| 17' | Leaflets entire. Ovary without irritant hairs |
| 18 | Hairs often mainly in stellate tufts, mixed with solitary simple hairs (N.B.: In some cases these may be hard to find, especially when the leaflets are almost glabrous) |
| 18' | Hairs solitary, simple, exceptionally two-branched (Litchi chinensis), if few small tufts of hairs present then leaves with pseudostipules (Pometia) |
| 19 | Sepals connate at the base. Petals absent or 1—5(—6) |
| 19' | Sepals free. Petals always 5 |
| 20 | Sepals valvate to narrowly imbricate in bud. Petals absent. Stamens 6 or 7, filaments glabrous. Ovary smooth |
| 20' | Sepals imbricate in bud. Petals absent or present. Stamens (6-)8(-10), filaments usually hairy. Ovary tuberculate |
| 21 | Leaves with pseudo-stipules |
| 21' | Leaves without pseudo-stipules |
| 22 | Leaflets entire or dentate (Pometia pinnata). Sepals slightly to distinctly unequal, free or up to halfway connate. Petals present |
| 22' | Leaflets dentate. Sepals equal, connate, somewhat less than halfway. Petals absent |
| 23 | Sepals free, imbricate, outer 1 or 2 distinctly smaller than inner 3. Stamens usually 8 (4-10) |
| 23' | Sepals up to halfway connate, not imbricate, slightly unequal. Stamens 5 (or 6) |
| 24 | Sepals free, imbricate, outer (1 or) 2 distinctly smaller than the inner three. |
| 24' | Sepals free or up to almost completely connate, apert, valvate or (slightly) imbricate, usually all equal, rarely slightly unequal |
| 25 | Leaflets (apically) crenate, serrate or dentate |
| 25' | Leaflets entire |
| 26 | Branchlets straight. Petals with 2 scales |
| 26' | Branchlets sinuate. Petal margin slightly folded, hairy |
| 27 | Leaf rachis often slightly winged. Leaflets shallowly crenate, or with few teeth near the apex, rarely (sub)serrate. Sepals petaloid, (sub)glabrous outside. Petal scales usually crested |
| 27' | Leaf rachis not winged. Leaflets dentate or serrate to crenate. Sepals not petaloid, at most the innermost one with a wide scarious rim, hairy outside. Petal scales not crested |
| 28 | Ovary and pistillode 2-celled |
| 28' | Ovary and pistillode 3- (or 4-)celled |
| 29 | Red glandular hairs present. Petals shorter than the sepals |
| 29' | No red glandular hairs. Petals as long as or longer than the sepals |
| 30 | Petals with 2 scales, or with auricles, but then sepals glabrous outside |
| 30' | Petals with 1 scale, rarely with a hairy ridge, if auricles present then sepals hairy outside |
| 31 | Sepals glabrous or slightly hairy outside |
| 31' | Sepals hairy outside |
| 32 | Leaves bicoloured, usually punctate, domatia normally present. Petal scales crested or not, auricles rarely present. Disc complete or interrupted |
| 32' | Leaves concoloured, not punctate, domatia absent. Petal scales or auricles not crested. Disc complete |
| 33 | Petiole and rachis marginate to winged or not. Inflorescences terminal, sometimes also in axils of the upper leaves. Stamens not exserted. Stigma conical or elongate, grooved. Ovules sessile on a thickened placenta |
| 33' | Petiole and rachis mostly not winged. Inflorescences terminal, axillary, rami- or cauliflorous. Stamens exserted or not. Stigma usually ± capitate, globular or dome-shaped, slightly lobed, rarely elongate, grooved. Placenta with an obturator |
| 34 | Leaves 1-5-jugate. Petals 5. Disc complete, annular |
| 34' | Leaves 7-13-jugate. Petals 4. Disc interrupted, semi-lunate |
| 35 | Petals with 1 scale |
| 35' | Petals with auricles or a hairy ridge |
| 36 | Petals usually absent, rarely up to 3 |
| 36' | Petals present, usually 5, sometimes reduced |
| 37 | Ovary smooth or warty, 1- or 2-, exceptionally 3-celled, usually lobed; stigma lobed, exceptionally grooved (Alectryon cardiocarpus: ovary 2-celled) |
| 37' | Ovary smooth, 3-celled, not lobed; stigma lobed or grooved |
| 38 | All hairs simple. Sepals connate or free, valvate or sligthly imbricate. Ovary lobed |
| 38' | Two-branched hairs often present. Sepals connate, apert. Ovary not lobed |
| 39 | Ovary smooth. Sepals connate. Leaflets opposite or more rarely alternate, smooth below, not glaucous |
| 39' | Ovary warty. Sepals free or connate. Leaflets alternate or more rarely to opposite, finely papillate below, mostly glaucous |
| 40 | Twigs puberulous, pubescent or patently hairy. Leaves 1 -5(-7)-jugate. Sepals free and imbricate or almost free to connate and apert or valvate. Stamens exserted. Stigma grooved or short to long lobed |
| 40' | Twigs strigose, at least when young. Leaves unifoliolate or 1-2-jugate. Sepals free, slightly imbricate. Stamens hardly exserted. Stigma slightly lobed |
| 41 | Twigs puberulous or pubescent. Leaves 1-5(-6)-jugate. Sepals almost free to connate, apert or valvate |
| 41' | Twigs patently hairy. Leaves 3-7-jugate. Sepals free, imbricate |
| 42 | Leaves 1-5(-6)-jugate. Anthers glabrous or hairy. Ovary stipitate |
| 42' | Leaves 2- or 3-jugate. Anthers glabrous. Ovary sessile |
| 43 | Petals without scales or auricles |
| 43' | Petals with scales or auricles |
| 44 | Sepals free or up to halfway connate, calyx flat or cup-shaped with a wide mouth and distinct lobes. Stamens 4-10 |
| 44' | Sepals almost totally connate, calyx urceolate with a narrow mouth and minute lobes. Stamens 5 |
| 45 | Inflorescences axillary, together often pseudoterminal, rarely truly terminal. Ovary warty |
| 45' | Inflorescences ramiflorous. Ovary smooth. |
| 46 | Leaflets alternate to more rarely opposite, lower surface mostly glaucous, without glands, with domatia. Stamens 4-10. Stigma lobed |
| 46' | Leaflets opposite, lower surface not glaucous, with flat orbicular glands, without domatia. Stamens 8, exceptionally 7 or 9. Stigma grooved |
| 47 | Twigs smooth or striate to slightly grooved. All leaves spirally arranged |
| 47' | Twigs with either 10-12 deep grooves or 6 slight grooves, rarely striate. At least upper leaves opposite or whorled, rarely spirally arranged. Ovary with irritant hairs |
| 48 | Petals with 1 scale, this sometimes deeply cleft |
| 48' | Petals with 2 scales or auricles |
| 49 | Leaflets entire, rarely slightly sinuous (Nephelium compression). Disc swollen, mostly free of the torus, without a rim or a collar. Anthers hairy. Ovary 2-, sometimes 3-celled |
| 49' | Leaflets hardly to coarsely crenate- to serrate-dentate, rarely entire. Disc composed of a flat ring, adnate to the torus except for the margin and with an erect rim or tubular collar. Anthers glabrous. Ovary 3-celled. N.B.: Paranephelium with paripinnate leaves may key out here. From Amesioden-dron it differs in the swollen disc without rim or collar, from Nephelium in the smooth, non-papillate lower surface of the leaflets, from Lepidopetalum and Trigo-nachras in the warty ovaries with lobed stigmas. |
| 50 | Lower surface of leaflets smooth, not glaucous. Petal scale entire or bifid. Ovary smooth, stigma grooved |
| 50' | Lower surface of leaflets finely papillate, glaucous. Petal scale bilobed. Ovary warty, stigma lobed, lobes spreading or recoiled |
| 51 | Lower surface of leaflets with axillary hairy domatia, without glands. Ovary 2-, rarely 3-celled, stigma folded outwards like an overhanging roof |
| 51' | Lower surface of leaflets without domatia, with glands. Ovary 3-celled, stigma cylindrical |
| 52 | Filaments glabrous. Stigma grooved |
| 52' | Filaments hairy, exceptionally glabrous (Mischocarpus pentapetalus, triqueter. ovary stipitate, stigma distinctly lobed). Stigma grooved or lobed |
| 53 | Sepals much connate. Petals with two scales |
| 53' | Sepals almost free. Petals with auricles |
| 54 | Upper surface of leaflets without wax, lower surface without small red glands 55 b. Upper surface of leaflets often with wax, lower surface with small red glands |
