1	Fruit not spotted with lenticels		(2)
+	Fruit spotted with lenticels		(8)
2 (1)	Pith solid, white; flowers white; sepals 2-5; petals 5-12		(3)
+	Pith lamellate, white or brown; flowers greenish, white, or red; sepals 4-6; petals 5		(5)
3 (2)	Sepals (4 or)5; petals 5; leaves adaxially sparsely strigillose.		5 A. polygama
+	Sepals 2 or 3; petals 5-12; leaves adaxially not strigillose		(4)
4 (3)	Fruit ovoid to obovoid, rostrum on apex ± conspicuous; seeds ca. 3 mm, ca. 2.5 mm in diam.; sepals (2 or)3; petals 5-9; anthers oblong to linear, 2.5-4 mm.		6 A. valvata
+	Fruit globose, rostrum on apex inconspicuous; seeds 4-5 mm, ca. 3 mm in diam.; sepals 2 or 3; petals 5-12; anthers ovoid, 1.5-2.5 mm.		7 A. macrosperma
5 (2)	Ovary bottle-shaped; flowers white or greenish; apex of fruit rostrate; pith white to brown; leaves abaxially glaucous or not		(6)
+	Ovary cylindric; flowers white to pink; apex of fruit not rostrate; pith brown; leaves abaxially not glaucous		(7)
6 (5)	Leaf blade abaxially usually not glaucous, ovate to broadly ovate or orbicular, sometimes ovate-oblong, membranous to papery.		1 A. arguta
+	Leaf blade abaxially usually glaucous, ovate-lanceolate, ovate-oblong, oblong, or ovate, occasionally orbicular, papery to leathery.		2 A. melanandra
7 (5)	Flowers pink or white, 5(or 6)-merous; leaves abaxially with ± conspicuous tufts of white hairs in axils of lateral veins.		3 A. kolomikta
+	Flowers white, 4-merous, rarely 5-merous; leaves abaxially with very conspicuous white tufts of hairs in axils of lateral veins.		4 A. tetramera
8 (1)	Leaves normally abaxially glabrous or occasionally hairy, but hairs not stellate or imperfectly stellate		(9)
+	Leaves abaxially ± tomentose, hairs stellate or imperfectly stellate		(30)
9 (8)	Branches and petioles pubescent, hairs usually rigid and long		(10)
+	Branches and petioles usually glabrous, if hairy, then hairs fine and soft, occasionally strigose on branchlets and petioles in A. fortunatii and A. callosa		(17)
10 (9)	Ovary setose; sepals abaxially hispidulous.		22 A. holotricha
+	Ovary and sepals tomentose (sepals occasionally glabrous)		(11)
11 (10)	Leaf margin irregularly setose-serrulate (usually with 2 short teeth in between 2 long ones).		23 A. rubus
+	Leaf margin regularly serrulate to serrate		(12)
12 (11)	Leaf blade orbicular-obovate, apex truncate and emarginate or rounded and cuspidate.		24 A. chengkouensis
+	Leaf blade oblong-lanceolate, ovate, or oblong-elliptic to oblong-obovate, apex acute to acuminate		(13)
13 (12)	Fruit oblong to globose, more than 1.5 cm in diam		(14)
+	Fruit cylindric, less than 1 cm in diam		(15)
14 (13)	Leaf blade oblong-lanceolate to -ovate, abaxially glaucous.		28 A. hemsleyana
+	Leaf blade oblong-ovate to broadly ovate, abaxially not glaucous.		29 A. vitifolia
15 (13)	Leaves ferruginous hispid, abaxially prominently glaucous.		25 A. melliana
+	Leaves strigose or puberulent, abaxially not or slightly glaucous		(16)
16 (15)	Both surfaces of leaves usually densely strigose, occasionally so on midvein and lateral veins to rarely glabrous, abaxially not glaucous; branchlets strigose, hairs basally not dilated.		26 A. rudis
+	Both surfaces of leaves often glabrous or slightly puberulent, adaxially occasionally sparsely strigose, abaxially glaucous or not; branchlets hispid-strigose, hairs basally obviously dilated.		27 A. henryi
17 (9)	Pith solid		(18)
+	Pith lamellate		(20)
18 (17)	Flowers 2-6, in subsessile, axillary clusters.		8 A. fasciculoides
+	Flowers solitary or in pedunculate clusters; peduncles or pedicels 1-2 cm		(19)
19 (18)	Inflorescences umbellate, usually 3-5-flowered.		9 A. umbelloides
+	Inflorescences cymose, usually 1-flowered.		10 A. rubricaulis
20 (17)	Leaves abaxially not glaucous		(21)
+	Leaves abaxially glaucous		(24)
21 (20)	Branchlets tomentose; inflorescence usually 3-9- or more flowered.		11 A. rufa
+	Branchlets rarely tomentose; inflorescence usually 1-3-flowered		(22)
22 (21)	Leaf margin inconspicuously mucronulate on current year leaves or shallowly crenate-serrate on two-year leaves; pith white to brown.		14 A. cylindrica
+	Leaf margin ciliate-serrulate to coarsely serrate; pith brown		(23)
23 (22)	Lenticels sparse, inconspicuous on branches; leaves with strongly raised parallel cross-bars on veinlets; flowers reddish.		12 A. ulmifolia
+	Lenticels dense, conspicuous on branches; leaves with slightly raised parallel cross-bars on veinlets; flowers white.		13 A. callosa
24 (20)	Branchlets with very conspicuous lenticels; leaves leathery to thickly leathery.		15 A. laevissima
+	Branchlets with inconspicuous to conspicuous lenticels; leaves papery to leathery		(25)
25 (24)	Pith white; flowers red; leaves basally distinctly cordatulate to auriculate- cordate.		16 A. fortunatii
+	Pith brown; flowers white or yellow; leaves basally cuneate to truncate or rounded, occasionally cordatulate		(26)
26 (25)	Young branchlets, young leaves abaxially on midvein and lateral veins, and inflorescences rusty glandular-tomentose		(27)
+	Young branchlets, young leaves abaxially on midvein and lateral veins, and inflorescences not rusty glandular-tomentose		(28)
27 (26)	Flowers yellow; leaf margin crenate-serrate; sepals on fruit persistent, reflexed.		17 A. chrysantha
+	Flowers white; leaf margin subentire to inconspicuously and remotely crenate-serrulate or serrulate toward apex; sepals not persistent on fruit.		18 A. indochinensis
28 (26)	Leaves on flowering branchlets apically rounded.		21 A. sabiifolia
+	Leaves on flowering branchlets never apically rounded		(29)
29 (28)	Leaf blade often narrowly ovate, base rounded, petiole 1.5-2.5 cm.		19 A. glaucocallosa
+	Leaf blade often oblong-ovate, base truncate, petiole 2.5-5 cm.		20 A. trichogyna
30 (8)	Abaxial surface of leaves imperfectly stellate pubescent		(31)
+	Abaxial surface of leaves perfectly stellate pubescent		(35)
31 (30)	Leaves minutely imperfectly stellate- or arachnoid pubescent		(32)
+	Leaves imperfectly long stellate, easily visible		(33)
32 (31)	Abaxial surface of leaves with minute hairs, and ± conspicuous parallel cross-bars on veinlets.		47 A. stellatopilosa
+	Abaxial surface of leaves with arachnoid hairs, and very prominent parallel cross-bars on veinlets.		48 A. venosa
33 (31)	Petals 5, 1-1.1 cm; pith white or brownish.		46 A. pilosula
+	Petals 5 or 6, 1-1.6 cm; pith brown		(34)
34 (33)	Inflorescence 3-7-flowered; flowers pink or rosy; leaf blade ovate-lanceolate.		44 A. zhejiangensis
+	Inflorescence 1-3-flowered; flowers yellow; leaf blade obovate.		45 A. grandiflora
35 (30)	Leaves usually with sparse, easily caducous, stellate hairs, hairs nearly fallen at fruiting		(36)
+	Leaves usually with ± dense persistent stellate hairs		(44)
36 (35)	Inflorescences 3- or 4-branched, 10- or more flowered.		32 A. latifolia
+	Inflorescences 1- or 2-branched, 1-7-flowered		(37)
37 (36)	Fruit glabrous when mature		(38)
+	Fruit tomentose when mature		(41)
38 (37)	Sepals 3-6, margin tomentose; petals 5 or 6, 7-9 mm.		40 A. hubeiensis
+	Sepals 4-6, both surfaces tomentose; petals 5-8, 9-20 mm		(39)
39 (38)	Petals 7 or 8; sepals 5 or 6; leaves leathery.		41 A. sorbifolia
+	Petals 5 or 6; sepals 4 or 5; leaves papery		(40)
40 (39)	Leaf blade obovate to obtriangular-obovate, apex abruptly acute to truncate		42 A. obovata
+	Leaf blade broadly ovate or broadly obovate to obovate, apex acute to abruptly acuminate to cuspidate.		43 A. lijiangensis
41 (37)	Fruit sparsely tomentose when mature; leaves oblong-ovate to broadly ovate when mature		(42)
+	Fruit densely tomentose when mature; leaves broadly ovate to orbicular when mature		(43)
42 (41)	Leaves abaxially glaucous near margins, reticulate veins not prominent.		49 A. persicina
+	Leaves abaxially not glaucous, reticulate veins prominent.		50 A. rongshuiensis
43 (41)	Fruit uniformly oblong, 2-4 cm.		51 A. longicarpa
+	Fruit ovoid to oblong, ca. 1.7 cm.		52 A. linguiensis
44 (35)	Both surfaces of leaves usually hairy, adaxially at least setose or strigose on midvein and lateral veins		(45)
+	Leaves abaxially hairy, adaxially glabrous or hairy when young, but glabrescent when mature		(51)
45 (44)	Peduncles subsessile; flowers in nearly fasciculate clusters; tomentum on leaves thickly cottony or not		(46)
+	Peduncles easily visible; flowers in cymose clusters; tomentum on leaves not cottony		(47)
46 (45)	Branchlets and petioles thickly lanate-pubescent.		30 A. farinosa
+	Branchlets and petioles setose-pubescent.		31 A. rufotricha
47 (45)	Inflorescences 3- or 4-branched, 10- or more flowered.		32 A. latifolia
+	Inflorescences 1- or 2-branched, 1-7-flowered		(48)
48 (47)	Leaves abaxially sparsely tomentose; branchlets and petioles brownish velutinous		33 A. fulvicoma
+	Leaves abaxially tomentose; branchlets and petioles densely tomentose or hirsute, occasionally velutinous		(49)
49 (48)	Branchlets and petioles tomentose.		33 A. fulvicoma
+	Branchlets and petioles hirsute or hispid-setose		(50)
50 (49)	Adaxial surface of leaves densely softly setose, branchlets and petioles hirsute.		33 A. fulvicoma
+	Adaxial surface of leaves densely scabrid-hispid, branchlets and petioles hispid-setose.		34 A. chinensis
51 (44)	Inflorescence 1-branched, 1-3-flowered; leaves abaxially long stellate, easily observed		(52)
+	Inflorescence 2-4-branched or racemiform, 5-10- or more flowered; leaves abaxially shortly stellate, not easily observed		(54)
52 (51)	Branchlets, buds, abaxial leaf surface, petioles, inflorescence, sepals, and fruit always with white indumentum.		38 A. eriantha
+	Branchlets and entire plant with yellowish brown or ferruginous indumentum, at least hairs on sepals and fruit yellowish brown		(53)
53 (52)	Leaf blade ovate, base cordate, lateral veins arcuate, often not furcate; fruit cylindric, to 1 cm in diam.		39 A. liangguangensis
+	Leaf blade obovate, base truncate or obtuse, lateral veins spreading, often furcate on upper part; fruit cylindric-globose or obovate.		34 A. chinensis
54 (51)	Male inflorescences racemiform, 14-20 cm; female inflorescences 1- or 2-branched, ca. 5 cm; pedicels stout.		35 A. suberifolia
+	Both male and female inflorescences cymose, 2-4-branched, at most 6-7 cm; pedicels slender		(55)
55 (54)	Peduncle 2.5-8.5 cm, inflorescence 10- or more flowered; leaf blade basally obtuse to rounded or cordatulate, more than 5 cm wide, petiole more than 3 cm.		32 A. latifolia
+	Peduncle to 1.5 cm, inflorescence 5-7-flowered; leaf blade basally cuneate to obtuse, 2-4.5 cm wide, petiole 1-2 cm		(56)
56 (55)	Pith white; leaf blade 4.5-5 cm wide, apex shortly acuminate, abaxially whitish tomentose with stellate hairs; branchlets, petioles, and inflorescences brownish velutinous.		36 A. styracifolia
+	Pith brown; leaf blade 2-3 cm wide, apex shortly acuminate to acuminate, abaxially grayish tomentose with stellate hairs; branchlets, petioles, and inflorescences ferruginous velutinous.		37 A. lanceolata