1	"Either herbs or shrubs (rarely climbers) with either leaves less than 15 mm wide and with entire margins or leaves reduced to scales."	2
1	"Either trees or shrubs (rarely climbers) with either leaves more than 15 mm wide or leaves less than 10 mm wide and the margins toothed."	21
2	"Inflorescence surrounded by an involucre and containing 1 female flower and 8–10 male flowers; perianth absent."	3
2	"Involucre absent; male and female flowers with perianth."	4
3	"Stems erect; leaves usually alternate on lower stems, subopposite or opposite above; stipules minute or absent."	Euphorbia
3	"Stems prostrate, decumbent or ascending; leaves opposite; stipules present, interpetiolar."	Chamaesyce
4	"Adult stems leafless, scale leaves present on young stems."	Amperea
4	"Normal leaves developed on all stems."	5
5	"Plants with stellate hairs."	6
5	"Plants glabrous or with simple hairs."	11
6	"Herbs with ovate to rhombic leaves, usually 20 mm or more wide, petiole at least as long as lamina."	7
6	"Shrubs, or herbs with leaves not as above, 15 mm or less wide; shortly petiolate."	8
7	"Plants with a dense, velvety covering of stellate hairs; leaves entire; style 1, simple; capsule smooth."	Eremocarpus
7	"Plants with a sparse covering of stellate hairs; leaves entire or sinuate-toothed; styles 3, bifid; capsule covered with peltate scales."	Chrozophora
8	"Flowers terminal (sometimes apparently axillary); sepals and petals usually present or rarely petals absent in female flowers."	9
8	"Flowers axillary; perianth usually in 1 whorl or rarely petals reduced or absent."	10
9	"Leaves white-woolly with a dense covering of stellate hairs; stipules present."	Croton
9	"Leaves glabrous, scabrous or with rusty-stellate hairs; stipules absent."	Ricinocarpos
10	"Styles either absent or if present then very short and fused, stigma simple, entire or lobed; fruit 3-seeded."	Beyeria
10	"Styles 3, obvious, 2–4-branched, stigmas separate; fruit usually 1-seeded."	Bertya
11	"Stipules present, often minute; male flowers with 3–9 stamens."	12
11	"Stipules absent; male flowers with numerous stamens."	19
12	"Leaves in groups of 3 at each node, the groups alternate on the stem."	Micrantheum
12	"Leaves not as above, leaves either alternate, opposite or whorled."	13
13	"Flowers terminal."	14
13	"Flowers axillary."	15
14	"Inflorescence a raceme or corymb, the rachis elongated; anthers opening by terminal pores."	Poranthera
14	"Inflorescence a dense cyme borne between the 2 terminal leaves at end of stems; anthers opening by longitudinal slits."	Monotaxis
15	"Female flowers enclosed by a large, rounded bract; leaves 20–40 mm long, toothed; petiole at least as long as lamina."	Acalypha
15	"Female flowers not enclosed by a large bract; leaves to 30 mm long, rarely toothed; petiole shorter than lamina."	16
16	"Stamens 6; some leaves opposite, others alternate on the same plant."	Pseudanthus
16	"Stamens 3; leaves all alternate."	17
17	"Fruit succulent, a berry; styles unbranched."	Breynia
17	"Fruit dry, a schizocarpic capsule; styles bifid."	18
18	"Disc or glands present; fruit depressed-globose."	Phyllanthus
18	"Disc or glands absent; fruit ovoid or more or less globose."	Sauropus
19	"Flowers mostly terminal; sepals and petals present, petals conspicuous and longer than the sepals."	Ricinocarpos
19	"Flowers axillary; perianth in one whorl or the petals rudimentary and shorter than the sepals."	20
20	"Styles either absent or if present then very short and fused, stigma simple, entire or lobed; fruit 3-seeded."	Beyeria
20	"Styles 3, obvious, 2–4-branched, stigmas separate; fruit usually 1-seeded."	Bertya
21	"Leaves with margins toothed, crenate or lobed."	22
21	"Leaves with margins entire or almost so."	36
22	"Leaves either unlobed or 3–5-lobed and then the lamina cut less than halfway towards base."	23
22	"Leaves deeply palmately 3–9-lobed, if 3–5-lobed then the lamina cut at least three-quarters of the way towards base."	35
23	"Leaves opposite."	24
23	"Leaves alternate."	25
24	"Leaves glabrous, finely toothed to crenate."	Austrobuxus
24	"Leaves hairy, coarsely toothed to more or less entire."	Mallotus
25	"Leaves with 1–5 small glands at apex of petiole or near base of lamina."	26
25	"Leaves without glands on lamina or petiole."	30
26	"Plants with milky latex; young shoots and leaves glabrous."	Excoecaria
26	"Plants without milky latex; young shoots and leaves mostly hairy or scaly."	27
27	"Leaves palmately 3–5-veined from base, often palmately lobed; petiole about as long as the lamina."	28
27	"Leaves pinnately veined, sometimes 3-veined in basal half; petiole usually shorter than lamina."	29
28	"Hairs stellate; ovary 1- or 2-locular; fruit with 1 or 2 seeds."	Aleurites
28	"Hairs simple; ovary 3–7-locular; fruit mostly with 3–7 seeds."	Vernicia
29	"Petioles with 3–5, rarely 1 or 2, glands on upper surface near apex of petiole; young shoots pubescent, leaves glabrous or sparsely hairy, hairs simple."	Claoxylon
29	"Petioles with 2 glands at junction with lamina; young shoots and leaves with scales or stellate hairs or sometimes leaves glabrous."	Croton
30	"Climbers; leaves and stems with stinging hairs."	Tragia
30	"Shrubs or trees; stinging hairs absent."	31
31	"Leaves stiff, glabrous; trees or tall shrubs."	32
31	"Leaves soft but firm, glabrous or hairy; shrubs less than 3 m high."	33
32	"Teeth spinose, margins with 2–4 pairs of teeth."	Alchornea
32	"Teeth not spinose, margins with more than 4 pairs of teeth or margins crenate."	Drypetes
33	"Bracts surrounding female flowers and fruits prominent, more or less circular, at least 4 mm and often more than 10 mm diam.; lamina either less than 20 mm long or if more than 20 mm long then pubescent with simple hairs."	Acalypha
33	"Bracts not as above; lamina more than 20 mm long, mostly stellate-hairy, sometimes glabrous."	34
34	"Plants pubescent, sometimes hoary, occasionally glabrous; leaves often lobed; perianth segments 6 or 8, in 2 whorls, c. 6 mm long, not persistent in fruit."	Adriana
34	"Plants densely tomentose; leaves unlobed; petals absent, calyx 6–9-lobed, persistent in fruit, lobes c. 9 mm long in fruit."	Croton
35	"Margins of leaves toothed, lamina peltate, mostly 7–9-lobed."	Ricinus
35	"Margins of leaves not toothed, lamina not peltate, mostly 3–7-lobed."	Manihot
36	"Leaves 1-foliolate, with a swelling at apex of petiole and mostly with 2 glands near base of lamina; translucent dots visible in lamina (lens needed); leaves opposite or alternate."	37
36	"Leaves simple, without a swelling at apex of petiole; glands absent or present near base of lamina or apex of petiole; leaves mostly alternate and without translucent dots."	38
37	"Buds scaly, reddish brown, more or less glabrous; 2 small embedded glands on margin of lamina c. 3 mm from base; leaves opposite."	Baloghia
37	"Buds not scaly, finely pubescent with fawn hairs; 2 depressed glands usually on lower lamina surface 5–10 mm from base; adult leaves alternate."	Fontainea
38	"Leaves opposite."	39
38	"Leaves alternate."	40
39	"Buds with scale leaves; plants more or less glabrous; leaves with petiole less than 10 mm long, secondary veins more than 10 pairs."	Baloghia
39	"Buds without scale leaves, plants covered with stellate hairs; leaves with petiole usually more than 10 mm long, secondary veins less than 9 pairs."	Mallotus
40	"Petioles more than 10 mm long; 1 or 2 glands often present near junction of petiole and lamina."	41
40	"Petioles less than 10 mm long, often c. 5 mm long; glands absent or sometimes present in Croton."	48
41	"Leaves peltate, petiole attached at least 10 mm in from margin; leaves palmately 9-veined."	Macaranga
41	"Leaves not peltate or if peltate then petiole attached less than 5 mm in from margin; leaves pinnately veined or palmately 3–5-veined."	42
42	"Young shoots and usually young leaves densely covered with hairs and/or scales, hairs simple or stellate."	43
42	"Leaves and shoots glabrous or almost so, hairs if present simple, stellate hairs and scales absent."	46
43	"Leaves not 3–5-veined from base; scales present, at least on young shoots, or hairs stellate and plant woolly."	Croton
43	"Leaves 3–5-veined from base; scales absent; at least young shoots and leaves hairy, hairs simple or stellate but not woolly."	44
44	"Lower surface of leaves with scattered, coloured surface glands, usually 3-veined from base; petals absent; leaves not lobed."	Mallotus
44	"Lower surface of leaves without coloured surface glands, mostly 5-veined from base; petals conspicuous, more than 8 mm long; leaves often lobed."	45
45	"Hairs stellate; ovary 1- or 2-locular; fruit 1- or 2-seeded."	Aleurites
45	"Hairs simple; ovary 3–5-locular; fruit 1–5-seeded."	Vernicia
46	"Leaves more or less triangular, petiole about as long as the lamina; petioles and stems often reddish."	Omalanthus
46	"Leaves not triangular, petiole less than half as long as the lamina; petioles and stems not reddish."	47
47	"Milky latex present; buds without scale leaves; 2 glands present at junction of petiole and lamina."	Excoecaria
47	"Milky latex absent; buds covered with scale leaves; glands absent from petiole and lamina."	Actephila
48	"Leaves with 12–15 pairs of secondary veins."	Briedelia
48	"Leaves with less than 12 pairs of secondary veins."	49
49	"Young shoots and leaves densely covered with either scales or stellate hairs."	Croton
49	"Young shoots and leaves glabrous or with simple hairs."	50
50	"Leaves distinctly 2-ranked and mostly pseudopinnate in arrangement."	51
50	"Leaves not distinctly 2-ranked, never pseudopinnate in arrangement."	52
51	"Lamina less than 30 mm long, glabrous, glaucous below, drying black above; fruit less than 5 mm diam."	Breynia
51	"Lamina more than 40 mm long, glabrous or finely pubescent, not glaucous below, not drying black; fruit more than 8 mm diam."	Glochidion
52	"Leaves glabrous and green on both surfaces, stiff, margin often obscurely crenate; fruit a drupe."	Drypetes
52	"Leaves glabrous and green above on fresh material, sometimes brownish to blackish above when dry, hairy and grey to fawnish below, firm but not stiff, margin entire or almost so; fruit a capsule."	53
53	"Leaves grey-green below, sparsely covered with pale-coloured hairs below; green above when dried; capsule 3-lobed, flattened-globose, 10–12 mm diam., green to reddish."	Cleistanthus
53	"Leaves fawnish grey below, densely covered with fawnish hairs, sometimes more or less glabrescent with age; capsule multilobed, more or less globose, 12–15 mm diam., usually orange-brown"	Petalostigma