1	Herbs twining; calyx tube rectilinear or slightly curved; utricle present; tube gradually dilated to funnelform apically; limb ligulate; gynostemium 6-lobed; anthers elliptic, opposite to lobes of gynostemium; capsule usually dehiscing acropetally.		(2)
+	Shrubs climbing, rarely shrubs erect or lianas; calyx tube horseshoe-shaped or geniculately curved at middle; limb often 2- or 3-lobed; gynostemium 3-lobed; anthers oblong, adnate in pairs opposite the gynostemium lobes; capsule usually dehiscing basipetally.		(18)
2 (1)	Utricle stipitate, with short stipe connected to ovary.		(3)
+	Utricle sessile, directly attached to ovary.		(6)
3 (2)	Leaf blade deeply 3-lobed.		42 A. polymorpha
+	Leaf blade entire or lobed.		(4)
4 (3)	Leaf blade glabrous on both surfaces, veins and veinlets sparsely reticulate.		43 A. tagala
+	Leaf blade densely puberulous or pubescent abaxially, at least along veinlets, veins and veinlets closely reticulate or foveolate-reticulate.		(5)
5 (4)	Leaf blade ovate-lanceolate to lanceolate, base auriculate, sinus 0.4-0.6 cm deep; seeds without wing.		44 A. impressinervis
+	Leaf blade triangular-ovate to rhombic-cordate, base shallowly cordate; seeds with wing.		45 A. zollingeriana
6 (2)	Leaf blade abaxially densely puberulous, hairs along veins and veinlets forming closely foveolate reticulation.		(7)
+	Leaf blade abaxially glabrous or pubescent, but without hairs along veins and veinlets.		(10)
7 (6)	Racemes less than 3 cm or flowers almost fasciculate.		(8)
+	Racemes 3-6 cm.		(9)
8 (7)	Leaf blade triangular-lanceolate to sagittate, base auriculate, lateral lobes parallel or spreading.		29 A. austrochinensis
+	Leaf blade ovate-lanceolate to lanceolate, base deeply cordate to auriculate, lateral lobes overlapping or slightly incurved.		30 A. foveolata
9 (7)	Bracts and bractlets ovate, ca. 1.5 × 1 cm, base cordate and slightly amplexicaul.		31 A. chlamydophylla
+	Bracts and bractlets subulate to ovate-lanceolate, 3-10 × 1-4 mm, base rounded to cuneate.		32 A. fordiana
10 (6)	Stems and leaves densely white or brownish villous.		33 A. fujianensis
+	Stems and leaves generally glabrous or glabrate (A. longganensis densely pubescent on abaxial leaf surface, otherwise glabrous).		(11)
11 (10)	Calyx limb with long-tailed or long-acuminate apex.		(12)
+	Calyx limb with obtuse to acute apex (occasionally long acuminate in A. zhongdianensis).		(13)
12 (11)	Leaf blade ovate-cordate or cordate to subrotund; seeds without wing.		34 A. longganensis
+	Leaf blade narrowly deltate to deltate-cordate; seeds with membranous wing.		35 A. contorta
13 (11)	Leaves sessile or subsessile; stems pruinose, with condensed nodes.		37 A. delavayi
+	Leaves petiolate; stems green, with elongate internodes.		(14)
14 (13)	Seeds obtusely deltoid, with membranous wing; capsule 4-6 cm in diam.		36 A. debilis
+	Seeds ovoid, without wing; capsule 1-2.5 cm in diam.		(15)
15 (14)	Leaf blade 0.5-4 × 0.5-5 cm, rounded-cordate, triangular-cordate, or subreniform; petiole 1-4 cm; bractlets subulate.		(16)
+	Leaf blade 3-15 × 3-16 cm, cordate or ovate-cordate; petiole 2-10 cm; bractlets ovate.		(17)
16 (15)	Leaf blade deltate-cordate, 0.5-3 × 0.5-2 cm, base auriculate.		38 A. zhongdianensis
+	Leaf blade cordate-reniform or rounded-cordate, 3-4 × 4-5 cm, base shallowly cordate.		39 A. gentilis
17 (15)	Leaf blade densely punctate; petiole and branchlets with red juice when broken; roots linear or terete.		40 A. tubiflora
+	Leaf blade not punctate; petiole and branchlets without red juice; roots fusiform or globose.		41 A. tuberosa
18 (1)	Calyx limb cylindric or saccate, 2-6-dentate or deeply 2- or 3-lobed.		(19)
+	Calyx limb discoid or obliquely trumpet-shaped, 3-lobed.		(24)
19 (18)	Calyx limb saccate, asymmetric.		(20)
+	Calyx limb cylindric or subcylindric (sometimes slightly expanded apically), symmetric.		(21)
20 (19)	Calyx limb ca. 6 × 1.5 cm; lobes lanceolate, ca. 25 × 10 mm.		23 A. forrestiana
+	Calyx limb 1-2 × 0.3-1.5 cm; lobes ovate-deltate, ca. 4 × 5 mm.		24 A. utriformis
21 (19)	Shrubs erect; stems and branchlets with condensed nodes; calyx limb 5- or 6-dentate.		25 A. thwaitesii
+	Shrubs or herbs climbing; stems and branchlets with elongate internodes; calyx limb 2- or 3-lobed.		(22)
22 (21)	Calyx limb indistinctly 2- or 3-lobed; lobes unequal.		26 A. transsecta
+	Calyx limb distinctly 3-lobed; lobes equal or slightly unequal.		(23)
23 (22)	Leaf blade ovate, abaxially densely gray or yellow-brown villous; calyx lobes subrounded.		27 A. ovatifolia
+	Leaf blade trullate-lanceolate, ovate-lanceolate, or lanceolate, abaxially sparsely pubescent or glabrescent; calyx lobes lanceolate-acuminate.		28 A. cucurbitoides
24 (18)	Calyx limb gradually dilated above, obliquely trumpet-shaped; lobes distinctly recurved, orifice larger than tube.		(25)
+	Calyx limb abruptly expanded, discoid, lobes plano-spreading, orifice distinctly smaller than tube.		(26)
25 (24)	Leaf blade base cordate, abaxially densely white tomentose; calyx with purple veins and blotches, orifice nearly quadrate.		21 A. saccata
+	Leaf blade base rounded, abaxially villous to glabrescent, hairs brownish or yellowish; calyx without blotches, orifice nearly orbicular.		22 A. hainanensis
26 (24)	Leaf blade polymorphic, margin deeply or shallowly lobed, rarely entire.		(27)
+	Leaf blade uniform, margin entire.		(31)
27 (26)	Leaf blade deeply palmately 5-7-lobed.		1 A. cucurbitifolia
+	Leaf blade margin never as above.		(28)
28 (27)	Calyx limb oblique, unilaterally 3-lobed, lobes ovate-lanceolate or oblong-lanceolate.		2 A. obliqua
+	Calyx limb not oblique, lobes broadly ovate or broadly deltate.		(29)
29 (28)	Leaf blade pandurate or obovate-oblong, subrotund on old branches.		3 A. thibetica
+	Leaf blade never as above.		(30)
30 (29)	Leaf blade ovate to ovate-lanceolate, obovate-oblong, or linear, margin entire or lobed near base, base cordate or auriculate, sinus over 0.5 cm wide.		4 A. kaempferi
+	Leaf blade broadly oblong-oblanceolate, linear, or oblong, margin entire or shallowly 2-3-lobed, base narrowly auriculate, sinus 0.3-0.5 cm wide.		5 A. howii
31 (26)	Leaf blade generally as wide as long, cordate to orbicular (rarely ovate); veins palmate, basal veins 5-7.		(32)
+	Leaf blade longer than wide, ovate to narrowly ovate, elliptic, oblong, or lanceolate; veins pinnate, often 4-6 pairs.		(39)
32 (31)	Leaf blade glabrous, base truncate.		6 A. caulialata
+	Leaf blade ± with hairs, base cordate or auriculate.		(33)
33 (32)	Flowers large, limb 3.5-12 cm in diam.		(34)
+	Flowers small; calyx limb 2-3.5 cm in diam.		(36)
34 (33)	Plants densely hirsute, hairs dusty yellow or brownish; calyx limb 3.5-4.5 cm in diam., dark purple, with spines, distinctly tuberculate.		7 A. kwangsiensis
+	Plants villous, hairs white or reddish brown; calyx limb 4-12 cm in diam., nearly smooth or sparsely papillate.		(35)
35 (34)	Calyx tube horseshoe-shaped at middle; limb 4-6 cm in diam.; seeds deltoid-cordiform or cordiform, 6-7 × 6-7 mm, both surfaces slightly plano-convex, verrucose.		8 A. manshuriensis
+	Calyx tube geniculately curved at middle; limb 6-12 cm in diam.; seeds ovoid, ca. 4 × 3 mm, upper surface plano-convex, lower deeply concave, with a septumlike funiculus at center, rugose or smooth.		9 A. griffithii
36 (33)	Leaf blade abaxially densely tomentose, hairs white or gray.		10 A. mollissima
+	Leaf blade abaxially sparsely to densely villous, hairs yellowish.		(37)
37 (36)	Calyx limb oblique, unilaterally 3-lobed, lobes ovate-lanceolate or oblong-lanceolate.		2 A. obliqua
+	Calyx limb not oblique, discoid or rounded, lobes rounded.		(38)
38 (37)	Leaf blade ovate to ovate-cordate, 5-12 cm wide, base deeply cordate or auriculate, sinus 1-2.5 cm deep; bractlets ovate, ca. 1.5 × 1 cm.		11 A. moupinensis
+	Leaf blade ovate to narrowly ovate, 4-8 cm wide, base shallowly cordate, sinus ca. 1 cm deep; bractlets subulate, 5-8 × 2-3 mm.		12 A. kunmingensis
39 (31)	Leaf blade base cordate or auriculate (sometimes narrowly so).		(40)
+	Leaf blade base rounded to shallowly cordate.		(43)
40 (39)	Flowers small; calyx limb 2-2.5 cm in diam.		(41)
+	Flowers large; calyx limb 4-13 cm.		(42)
41 (40)	Racemes 3-5-flowered, cauliflorous; leaf blade base cordate, sinus 1-2 × 1-2 cm.		13 A. scytophylla
+	Flowers solitary or paired, axillary; leaf blade base narrowly auriculate, sinus 0.5-1.5 × 0.2-0.4 cm.		14 A. fulvicoma
42 (40)	Calyx limb 8-13 cm in diam.		15 A. westlandii
+	Calyx limb 4-6 cm in diam.		16 A. versicolor
43 (39)	Calyx limb adaxially papillate; leaf blade lanceolate, elliptic-lanceolate, or linear-lanceolate.		(44)
+	Calyx limb adaxially smooth; leaf blade oblong, ovate-oblong, or ovate, rarely ovate-lanceolate.		(45)
44 (43)	Calyx tube upper part abruptly dilated into limb, margin not revolute.		17 A. championii
+	Calyx tube upper part gradually dilated into limb, margin revolute.		18 A. bambusifolia
45 (43)	Calyx tube horseshoe-shaped curved at middle; leaf blade base rounded.		19 A. fangchi
+	Calyx tube geniculately curved at middle; leaf blade base shallowly cordate.		20 A. petelotii