1	Sepals free or connate beyond attachment to ovary, without distinct tube or only with very short one; sepals abaxially pubescent; stamen filaments usually longer than anthers; styles connate into column, apex entire or notched; stigmas terminal; ovary inferior.		(2)
+	Sepals connate beyond attachment to ovary, forming variously shaped tube; sepals abaxially glabrous, rarely pubescent; stamen filaments very short or nearly lacking; styles free or rarely united at base, apex often notched or 2-cleft; stigmas lateral, rarely terminal; ovary superior or inferior.		(12)
2 (1)	Sepals connate beyond attachment to ovary, forming a calyx tube.		(3)
+	Sepals free beyond attachment to ovary (sometimes connivent but not connate).		(7)
3 (2)	Calyx actinomorphic, lobes triangular, apically acute; styles slender; stigmas not radiating downward; leaves paired on flowering shoots, solitary on nonflowering shoots.		(4)
+	Calyx slightly zygomorphic, lobes triangular-orbicular to rounded-ovate, apically rounded; styles short and thick, stigmas radiating downward, subdecurrent; leaves paired on flowering and nonflowering shoots.		(5)
4 (3)	Stamens 6-9; flowers (including lobes) less than 1 cm; calyx lobes erect.		6 A. debile
+	Stamens 12; flowers (including lobes) more than 1.5 cm; calyx lobes spreading.		7 A. caudigerellum
5 (3)	Leaf blade narrowly ovate or ovate-lanceolate, apex acuminate; anthers 0.8-1.2 mm; connectives less than 0.3 mm.		11 A. epigynum
+	Leaf blade ovate, ovate-cordate, or broadly ovate, apex acute or obtuse; anthers 2-3 mm; connectives 0.7-1.3 mm.		(6)
6 (5)	Leaf blade 13-22 cm; stamen filaments 0.4-0.7 mm.		9 A. yunnanense
+	Leaf blade 5-10 cm; stamen filaments less than 0.4 mm.		10 A. geophilum
7 (2)	Calyx lobes erect or spreading, caudate to acuminate, rarely acute.		(8)
+	Calyx lobes reflexed and appressed to false tube, rounded, obtuse, or acute.		(10)
8 (7)	Shoots elongate, internodes 2-6 cm.		3 A. cardiophyllum
+	Shoots condensed, internodes less than 2 cm.		(9)
9 (8)	Calyx lobe abruptly caudate at apex, tail 10-25 mm; style lobes entire, stigmas terminal.		1 A. caudigerum
+	Calyx lobe gradually caudate at apex, tail 2-4 mm; style lobes notched, stigmas at base of notch.		2 A. renicordatum
10 (7)	Plants densely covered with long white hairs, hairs turning black when dried.		4 A. pulchellum
+	Plants only sparingly to moderately pubescent, hairs remaining white when dried.		(11)
11 (10)	Leaves paired on vegetative shoots; stamens and styles slightly exserted.		5 A. caulescens
+	Leaves solitary on vegetative shoots; stamens and styles included.		8 A. himalaicum
12 (1)	Stamen filaments longer than anthers; leaves paired on vegetative shoots; styles short; calyx tube without laminate ring.		(13)
+	Stamen filaments usually very short; leaves solitary on vegetative shoots; styles long; calyx tube usually with laminate ring at throat.		(14)
13 (12)	Calyx lobes erect or spreading, never reflexed at anthesis; leaf blade apex shortly acuminate or acute, adaxially sparsely pubescent.		12 A. sieboldii
+	Calyx lobes reflexed at anthesis; leaf blade apex acute or obtuse, adaxially shortly pubescent along veins.		13 A. heterotropoides
14 (12)	Styles entire at apex, rarely slightly 2-cleft; stigmas terminal or subterminal.		(15)
+	Styles conspicuously 2-fid or notched at apex; stigmas lateral.		(18)
15 (14)	Calyx tube strongly constricted at throat, adaxial surface tessellate (sometimes only inconspicuously transversely corrugate), orifice ring present.		(16)
+	Calyx tube slightly or not constricted at throat, adaxial surface longitudinally rugose, orifice ring absent.		(17)
16 (15)	Rhizomes long spreading, horizontal; leaf blade elliptic or ovate, rarely cordate, apex acuminate; calyx tube gradually dilated above orifice forming short neck, then divided into lobes.		14 A. chinense
+	Rhizomes short, vertical; leaf blade cordate or ovate-cordate, apex acute to obtuse; calyx tube without neck, divided immediately into lobes.		15 A. ichangense
17 (15)	Leaf blade ovate-cordate to ovate, both surfaces glabrous, adaxially shiny; lateral calyx lobes erect or spreading; connectives obtuse; styles connate, apex with 6, erect, slightly 2-cleft arms.		16 A. hongkongense
+	Leaf blade triangular-ovate to narrowly ovate, pubescent, adaxially not shiny; lateral calyx lobes reflexed; connectives awl-shaped; styles 6, free, apex entire.		17 A. fukienense
18 (14)	Calyx tube inner surface tessellate.		(19)
+	Calyx tube inner surface with longitudinal ridges, sometimes with crossbars, but not tessellate.		(29)
19 (18)	Calyx tube slightly or not at all constricted at throat, orifice ring narrow (ca. 1 mm or less wide) or absent.		(20)
+	Calyx tube strongly constricted at throat, orifice ring broad and evident (2.5-5 mm wide).		(24)
20 (19)	Calyx tube broadly cupular or subglobose, orifice ca. 15 mm in diam., ring absent.		18 A. splendens
+	Calyx tube subcylindric to campanulate, orifice 4-8 mm in diam., ring absent or present.		(21)
21 (20)	Calyx lobes adaxially pubescent, spreading, orifice ring absent.		22 A. taipingshanianum
+	Calyx lobes adaxially glabrous (sometimes papillose), erect or slightly spreading, orifice ring present.		(22)
22 (21)	Leaf blade broadly cordate to reniform-cordate, length and width subequal; calyx lobes adaxially smooth, without papillate area.		19 A. forbesii
+	Leaf blade triangular-oblong to triangular-ovate, length greater than width; calyx lobes adaxially papillose or rugose at base.		(23)
23 (22)	Leaves 6-17 × 5-16 cm; petiole 8-25 cm; calyx lobes 1.5-2 × 2-2.5 cm, with rounded papillose area at base (Sichuan).		21 A. bashanense
+	Leaves 3-7 × 2.3-2.9 cm; petiole 5-8 cm; calyx lobes ca. 0.4 × 0.5 cm, irregularly thickened, glandular-rugose at base (Taiwan).		20 A. crassisepalum
24 (19)	Stigmas elongate, linear-oblong or oblong-ovoid; style apex hooked; calyx lobe margins undulate.		(25)
+	Stigmas not elongate, rounded to ovoid; style apex not hooked; calyx lobe margins hardly undulate.		(26)
25 (24)	Leaf blade triangular-ovate, abaxially with purple veins; petiole streaked reddish brown; stamens oblong; connectives thick and notched at apex; stigmas linear-oblong; style apex distinctly hooked.		23 A. macranthum
+	Leaf blade ovate-cordate or narrowly ovate, abaxially with green veins; petiole uniformly green; stamens triangular; connectives obtuse or acute, entire at apex; stigma oblong-ovoid; style apex obscurely hooked.		24 A. crispulatum
26 (24)	Flower 2-2.5 cm in diam., calyx tube urceolate, 1-1.2 × 1.1-1.4 cm, orifice ring ca. 1 mm wide.		28 A. porphyronotum
+	Flowers more than 3 cm in diam.; calyx tube subcylindric or conic, 1.5-2 × 0.7-1.5 cm, orifice ring 1.5-3 mm wide.		(27)
27 (26)	Petiole 4-7 cm, pilose at maturity; calyx 2.5-3 cm in diam.		27 A. chengkouense
+	Petiole 10-21 cm, glabrous at maturity; calyx 3-6 cm in diam.		(28)
28 (27)	Connectives slightly extended beyond anthers, apex awl-shaped; calyx lobes broadly ovate, 2-3 × 3-4 cm.		25 A. delavayi
+	Connectives not extended beyond anthers, apex rounded; calyx lobes subrotund, ca. 1 × 2 cm.		26 A. hypogynum
29 (18)	Calyx tube abruptly swollen toward middle or above, forming barrel-shaped dilated zone.		(30)
+	Calyx tube cylindric or enlarged gradually, but lacking prominent dilated zone.		(32)
30 (29)	Calyx lobes with pinkish, triangular papillate area at base; tube above abruptly swollen into broad disk which is longitudinally ridged, orifice very constricted, ring broad.		29 A. inflatum
+	Calyx lobes with white or yellowish, circular or semicircular pulvinate area at base; tube with robust dilated zone at middle inner surface without ridges, orifice ring absent.		(31)
31 (30)	Calyx tube swollen forming girdle-like ring near middle, lobes with papillate transverse rows at base, orifice ca. 1 cm in diam.; peduncle 1-5 cm.		30 A. maximum
+	Calyx tube swollen with girdle-like ring near apex, lobes without papillate transverse rows, orifice small, less than 1 cm in diam.; peduncle 2-9.5 cm.		31 A. insigne
32 (29)	Calyx tube and abaxial surface of leaf blade densely yellowish brown pubescent; peduncle recurved, pubescent.		37 A. wulingense
+	Calyx tube and leaf blade abaxially glabrous or only veins with hairs; peduncle erect, subglabrous.		(33)
33 (32)	Orifice ring absent or inconspicuous (rarely formed by papillae, but not as a contiguous ring); calyx tube 2-5 cm, slightly or not at all constricted at throat.		(34)
+	Orifice ring present, conspicuous, 2-3 mm wide; calyx tube 1-2.5 cm, slightly to strongly constricted at throat.		(36)
34 (33)	Calyx 2.5-3 cm wide; tube 2-2.5 cm, lobes with minute pulvinate area (ca. 2 mm in diam.) or scattered papillae at base, papillae not forming ribs in tube; petiole 2.5-7.5 cm.		32 A. nanchuanense
+	Calyx 4-5 cm wide; tube 3-5 cm, lobes usually with prominent papillate area at base, over 5 mm in diam., papillae extending in longitudinal rows from base to form ribs in tube; petiole 6-23 cm.		(35)
35 (34)	Calyx tube erect and symmetric, throat not constricted, rarely with papillate ring; leaf blade triangular-ovate to elliptic-ovate, apex acute to shortly acuminate; rhizomes short, vertical.		38 A. magnificum
+	Calyx tube often inclined to one side, slightly asymmetric, throat slightly constricted; leaf blade narrowly ovate, triangular-ovate, or oblong-hastate, apex long acuminate; rhizomes elongated, horizontal.		39 A. petelotii
36 (33)	Calyx lobes not conspicuously pubescent adaxially.		(37)
+	Calyx lobes densely pubescent adaxially.		(38)
37 (36)	Plants robust, with short rhizomes and thick, fleshy roots; leaf blade narrowly or broadly ovate to triangular-ovate, 11-14 cm wide; flowers usually paired; stamen connectives awl-shaped.		33 A. sagittarioides
+	Plants slender, with long rhizomes and fibrous roots; leaf blade oblong-ovate or narrowly elliptic-ovate, 5-8 cm wide; flowers solitary; stamen connectives ligulate.		34 A. longerhizomatosum
38 (36)	Calyx tube cylindric, 0.9-1.5 cm in diam.; leaf blade adaxially uniformly green.		36 A. tongjiangense
+	Calyx tube lantern-shaped, slightly swollen at middle, ca. 2 cm in diam.; leaf blade adaxially faintly white spotted.		35 A. nobilissimum