1	Rootstock a subglobose tuber up to 3 cm in diam., roots sometimes thickened but not distinctly fusiform; leaf blade hastate; corolla exterior minutely hairy, lobes joined for apical third to half to form flat "roof"		1 Ceropegia aridicola
+	Rootstock where known a cluster of fusiform roots and/or an elongated rhizome, subglobose tuber absent; leaf blade linear-lanceolate to ovate; corolla exterior glabrous, lobes joined at tip only to form open "cage."		(2)
2 (1)	Apex of flower buds abruptly narrowed at throat into beak with swollen tip; corolla lobes distinctly spatulate.		(3)
+	Apex of flower buds rounded or if beaked, not swollen at tip; corolla lobes linear-oblong to ovate.		(4)
3 (2)	Corolla very slender, up to 3.5 mm wide at throat, lobes 1.8-2 cm		11 Ceropegia trichantha
+	Corolla broader, 5.5-8 mm wide at throat, lobes 0.9-1.5 cm		12 Ceropegia driophila
4 (2)	Corolla throat narrower than inflated base.		(5)
+	Corolla throat wider than inflated base.		(10)
5 (4)	Corolla lobes uniformly colored.		(6)
+	Corolla lobes with pale basal part, sometimes with fine dark veins, and sharply delineated dark apical part, usually purple, possibly dark green, often hairy.		(7)
6 (5)	Inflorescences often more than 2-flowered; stems densely crisped pubescent; leaf blade more than 5 × as long as wide; corolla tube slightly narrower than throat, lobes linear; outer corona lobes 2-toothed		16 Ceropegia muliensis
+	Inflorescences 1- or 2-flowered; stems sparsely pilose on 1 side; leaf blade less than 4 × as long as wide; corolla narrowing gradually from base to throat, lobes spatulate; outer corona lobes reduced to ill-defined ciliate flanges		17 Ceropegia hookeri
7 (5)	Corolla lobes 5-7 mm, broadly lanceolate, corolla widening above base of lobes		2 Ceropegia teniana
+	Corolla lobes 11-25 mm, linear to narrowly oblong, corolla not widening above base of lobes.		(8)
8 (7)	Erect herbs to 20 cm high; inflorescences 2-4-flowered		3 Ceropegia sinoerecta
+	Robust twiners 1 m or more high; inflorescences 5- or more flowered.		(9)
9 (8)	Corolla lobes 2-2.5 cm, glabrous; outer corona lobes entire		13 Ceropegia pubescens
+	Corolla lobes 1.1-1.6 cm, hairy; outer corona lobes each with 2 linear teeth		7 Ceropegia longifolia
10 (4)	Corolla lobes ovate, uniform in color and indumentum, corolla at anthesis widest part way up lobes; inflorescences (4-)6-10-flowered.		(11)
+	Corolla lobes linear to narrowly oblong and sharply differentiated by color and indumentum from triangular base, corolla at anthesis widest at base of lobes; inflorescences 1-4(-7)-flowered (8- or more flowered in C. longifolia).		(12)
11 (10)	Leaf blade ovate, up to 2 × as long as broad		14 Ceropegia monticola
+	Leaf blade lanceolate, more than 4 × as long as broad		15 Ceropegia salicifolia
12 (10)	Corolla lobes ca. 1/4 as long as corolla, linear, abruptly contracted from triangular base, bud with distinct narrow beak less than 1/3 as wide as corolla at base of lobes		4 Ceropegia exigua
+	Corolla lobes more than 3/10 as long as corolla, oblong, bud with indistinct beak more than 1/2 as wide as corolla at base of lobes.		(13)
13 (12)	Leaves glabrous		10 Ceropegia paohsingensis
+	Leaves hairy, at least on veins.		(14)
14 (13)	Leaf blade linear-lanceolate, 0.2-1.5(-2) cm wide, (4-)7- > 10 × as long as broad.		(15)
+	Leaf blade ovate, 1.2-3 cm wide, 1.5-3(-4) × as long as broad.		(16)
15 (14)	Leaves (5-)8-15(-2) mm wide; outer corona lobes each with 2 slender teeth		5 Ceropegia dolichophylla
+	Leaves 2-7 mm wide; outer corona lobes each with 2 short, blunt teeth		6 Ceropegia stenophylla
16 (14)	Peduncle 9-27 mm; inflorescences 4- > 8-flowered; upper parts of plant sparsely hairy		7 Ceropegia longifolia
+	Peduncle up to 4 mm, often almost absent; inflorescences rarely if ever more than 2-flowered; upper parts of plant densely hairy.		(17)
17 (16)	Leaf blade base cuneate; corolla (2.3-)4.3-4.9 cm		8 Ceropegia mairei
+	Leaf blade base rounded; corolla ca. 5 cm		9 Ceropegia christenseniana