1	"Plants leafless"	2
1	"Leaves well developed, at least 10 mm long"	4
2	"Stems terete, grey, not toothed; flowers 0.2-0.7 cm wide, white"	Cynanchum
2	"Stems angular, green, toothed; flowers 6-15 cm wide, reddish-brown"	3
3	"Stems with patent hairs up to 0.3 mm long; corolla c. 15 cm wide, with many long hairs (Stapelia gigantea)"	Stapelia
3	"Stems glabrous; corolla c. 6 cm wide, glabrous (Orbea variegata)"	Orbea
4	"Trees, shrubs or erect herbs"	5
4	"Climbing, sprawling or twining vines"	31
5	"Leaves spirally arranged"	6
5	"Leaves opposite or in whorls"	7
6	"Leaves 5-10 mm wide, secondary veins obscure; corolla bright yellow (Cascabela thevetia)"	Cascabela
6	"Leaves 25-75 mm wide, secondary veins conspicuous; corolla white, sometimes with a red centre"	Cerbera
7	"At least some leaves in whorls of 3-7"	8
7	"All leaves opposite, none in whorls"	14
8	"Leaves spine-tipped"	Alyxia
8	"Leaf apex acute or obtuse, not spinose"	9
9	"Leaves in each whorl of unequal size, the largest more than twice as long as the smallest (Rauvolfia tetraphylla)"	Rauvolfia
9	"Leaves in each whorl all the same size"	10
10	"Lateral veins of leaf 1-2 mm apart; corolla 35-45 mm long; colleters on petiole, near junction with stem (Nerium oleander)"	Nerium
10	"Lateral veins of leaf 2.5-8 mm apart; corolla 5-18 mm long; colleters absent"	11
11	"Fruits 12-40 cm long, linear, not fleshy, dehiscent"	Alstonia
11	"Fruits 1.2-6 cm long, ovoid or ellipsoidal, fleshy, indehiscent"	12
12	"Scandent shrub; leaves 3.5-7.5 cm long; fruits globose, c. 10 mm long or moniliform with 2 globose articles (Alyxia spicata)"	Alyxia
12	"Erect shrubs; leaves 7-19 cm long; fruits ellipsoidal, (12-)35-70 mm long"	13
13	"Disc present at style-base; endocarp without obvious cavities"	Neisosperma
13	"Disc absent at style-base; endocarp with 2 cavities"	Ochrosia
14	"Leaf axils bearing long (sometimes branched) spines"	Carissa
14	"Plants without spines"	15
15	"Small annual erect herbs with very slender leaves (largest leaves < 4 mm wide)"	16
15	"Perennial shrubs or trees, largest leaves > 7 mm wide"	17
16	"Plant arising from a discoid tuber; flowers 10-12 mm long; pedicels 7-25 mm long (Brachystelma glabriflorum)"	Brachystelma
16	"Plants without a tuber; flowers 2-4.5 mm long; pedicels 1.5-2.5 mm long (Vincetoxicum brachystelmoides)"	Vincetoxicum
17	"Leaf base cordate to auriculate"	18
17	"Leaf base cuneate to attenuate"	19
18	"Leaves sessile, < 2 times longer than broad, glabrous or sparsely hairy; shrub 2-4 m high; flowers creamy"	Calotropis
18	"Leaves with petiole 6-12 mm long, 2-3 times longer than broad, densely hairy; shrub 0.5-1.2 m high; flowers blue (Oxypetalum coeruleum)"	Oxypetalum
19	"Colleters present at junction of petiole and stem"	20
19	"Colleters absent or not located at the petiole/stem junction"	21
20	"Shrub to 1.5 m high; leaves concolorous; follicles 6-7.5 cm long (Gymnanthera cunninghamii)"	Gymnanthera
20	"Trees 7-40 m high; leaves discolorous; follicles 11-35 cm long"	Wrightia
21	"Two raised glands present on the upper half of the petiole; a sprawling stoloniferous shrub; flowers blue (Vinca major)"	Vinca
21	"Petiole without any glands; erect shrubs or trees without stolons; flowers white, or sometimes pink or orange-red"	22
22	"Base of petiole expanded into a small erect ovate appendage appressed to the branchlet; mature fruits orange"	Tabernaemontana
22	"Base of petiole not expanded, appendage absent; mature fruits green or brown to black"	23
23	"Petioles more than 10% length of lamina; lamina margin undulate; fruits linear, 7-26 cm long (Alstonia constricta)"	Alstonia
23	"Petioles less than 10% length of lamina; lamina margin entire; fruits oblong to globose, 2-12 cm long"	24
24	"Leaves 5-9 times longer than wide; inflorescence umbelliform"	25
24	"Leaves 2-5 times longer than wide; inflorescence 1-2-flowered, or racemose, or paniculate"	27
25	"Stems with very dense patent hairs; latex yellow; flowers brown or green (Vincetoxicum erectum)"	Vincetoxicum
25	"Stems glabrous or with sparse appressed hairs; latex white; flowers white, or red and orange"	26
26	"Flowers white; follicles ovoid to globose"	Gomphocarpus
26	"Flowers red and orange; follicles fusiform (Asclepias curassavica)"	Asclepias
27	"Small shrub to 1 m high; lateral leaf veins at < 45 degrees to midrib; fruits dry"	28
27	"Shrubs or trees 2-8 m high; lateral leaf veins at 45-80 degrees to midrib; flowers in panicles; fruits fleshy"	29
28	"Flowers solitary or in pairs; corolla 30-50 mm long; colleters absent from base of lamina (Catharanthus roseus)"	Catharanthus
28	"Inflorescence racemose; corolla 4-8 mm long; colleters present at base of lamina (Cynanchum floribundum)"	Cynanchum
29	"Leaves bluntly acuminate, terminated by a broad gland 0.8-1.6 mm wide (Kopsia arborea)"	Kopsia
29	"Leaves acute or obtuse, without a terminal gland"	30
30	"Largest leaves 6-12 cm long; calyx 2-3.5 mm long, fused only at base; fruits indehiscent; naturalised species (Acokanthera oblongifolia)"	Acokanthera
30	"Largest leaves 18-35 cm long; calyx 13-15 mm long, fused for most of its length; fruits dehiscent; indigenous species (Voacanga grandifolia)"	Voacanga
31	"Leaves in whorls"	32
31	"Leaves opposite"	33
32	"Stems glabrous; leaf apex obtuse; flowers 4-6 mm long"	Alyxia
32	"Stems sparsely to densely hairy; leaf apex acute to acuminate; flowers 50-120 mm long"	Allamanda
33	"Epiphytic or lithophytic vines"	34
33	"Scramblers or lianas, not lithophytic or epiphytic; leaves herbaceous to coriaceus, occasionally fleshy"	36
34	"Leaves not fleshy; corolla tube longer than lobes (Ichnocarpus rhombifolius)"	Ichnocarpus
34	"Leaves fleshy or succulent; corolla tube equal to or shorter than lobes"	35
35	"Not rooting at the nodes; staminal corona of lobes with inrolled keels"	Hoya
35	"Rooting at the nodes; staminal corona of lobes with variously branched apices"	Dischidia
36	"Colleters present at base of lamina"	37
36	"Colleters absent from base of lamina"	50
37	"Upper leaf surface hairy, at least along the midrib"	38
37	"Upper leaf surface glabrous"	43
38	"Leaves white or greyish white below due to very dense hairs c. 0.1 mm long; corolla tube 12-15 mm long (Araujia sericifera)"	Araujia
38	"Leaves green or grey-green below, hairs > 0.2 mm long; corolla tube 1-6 mm long"	39
39	"Most or all hairs on stem in longitudinal bands"	40
39	"Hairs on stems +/- evenly distributed"	41
40	"Flowers white, depressed globose, corolla lobes c. 1 mm long (Gunnessia pepo)"	Gunnessia
40	"Flowers brown, campanulate, corolla lobes 3-5 mm long (Sarcolobus hullsii)"	Sarcolobus
41	"Gynostegium markedly capitate; pollinia globose to subglobose"	Vincetoxicum
41	"Gynostegium not markedly capitate; pollinia oblong to ellipsoidal"	42
42	"Corona segments adnate to staminal column, erect"	Leichhardtia
42	"Coronas reduced to 5 hardly visible lobes or ridges on lower part of corolla tubes, or absent"	Gymnema
43	"Domatia present as hair tufts along midrib on lower leaf surface; doubtfully naturalised (Mandevilla laxa)"	Mandevilla
43	"Domatia absent; native taxa"	44
44	"Petiole and lower leaf surface with reddish-brown hairs"	Secamone
44	"Petiole and lower leaf surface glabrous or with white hairs"	45
45	"Corolla 19-30 mm long, lobes connate at apex (Ceropegia cumingiana)"	Ceropegia
45	"Corolla 1-8 mm long, lobes free"	46
46	"Leaf base cordate or auriculate"	47
46	"Leaf base cuneate to truncate"	49
47	"Pedicels 12-15 mm long (Heterostemma acuminatum)"	Heterostemma
47	"Pedicels 1.5-12 mm long"	48
48	"Flowers 2.5-3 mm diameter; pedicels 1.5-5 mm long (Sarcolobus vittatus)"	Sarcolobus
48	"Flowers 5-10 mm diameter; pedicels 4-12 mm long"	Cynanchum
49	"Gynostegium markedly capitate; pollinia globose to subglobose; latex usually clear"	Vincetoxicum
49	"Gynostegium not markedly capitate; pollinia oblong to ellipsoidal; latex usually white"	Leichhardtia
50	"Largest leaves very slender, less than 4 mm wide OR leaf apex apiculate, the apiculum 1-2 mm long"	Vincetoxicum
50	"Largest leaves more than 6 mm wide AND leaf apex not apiculate"	51
51	"Latex watery, clear or yellowish"	Parsonsia
51	"Latex milky"	52
52	"Petioles 1-6 mm long"	53
52	"Petioles 6-45 mm long"	54
53	"Longest leaves 70-160 mm long; fruits fleshy, indehiscent, seed without a coma"	Melodinus
53	"Longest leaves 30-50 mm long; fruits dry, dehiscent, seed comose (Secamone elliptica)"	Secamone
54	"At least the younger leaves hairy"	55
54	"Leaves glabrous"	56
55	"Younger leaves hairy, at least on the midrib below; a dense network of tertiary veins prominent on lower leaf surface; flowers 4.5-6 mm long; native (Ichnocarpus frutescens)"	Ichnocarpus
55	"All leaves densely hairy on the lower surface; tertiary veins on lower leaf surface widely spaced, not prominent; flowers 60-70 mm long; doubtfully naturalised (Chonemorpha fragrans)"	Chonemorpha
56	"Secondary leaf veins at c. 45 degrees to the midrib"	Parsonsia
56	"Secondary leaf veins at 60-80 degrees to the midrib"	57
57	"Flowers 50-70 mm long and wide (Cryptostegia grandiflora)"	Cryptostegia
57	"Flowers 11-17 mm long, 5-25 mm wide"	58
58	"Corolla maroon inside, rotate, fused portion very short (Phyllanthera grayi)"	Phyllanthera
58	"Corolla cream to yellow-green inside, salverform, tube longer than lobes (Gymnanthera oblonga)"	Gymnanthera