1	Inflorescences borne on erect, long, leafy shoots of current year arising from base of shrub, sometimes on short, lateral branchlets arising from branches of previous year.		(2)
+	Inflorescences borne on short, lateral branchlets arising from (often arching) branches of previous year.		(30)
2 (1)	Inflorescences paniculate, oblong or pyramidal.		1 S. salicifolia
+	Inflorescences broadly compound corymbose.		(3)
3 (2)	Inflorescences borne on erect, long, leafy shoots of current year.		(4)
+	Inflorescences borne on short, lateral branchlets arising from branches of previous year.		(9)
4 (3)	Inflorescences glabrous; flowers white; follicles erect.		7 S. fritschiana
+	Inflorescences pubescent; flowers usually pink, rarely purple-red; follicles divergent.		(5)
5 (4)	Leaf blade base truncate to rounded; petiole (2–)4–8 mm.		(6)
+	Leaf blade base cuneate to broadly so; petiole 1–3 mm.		(7)
6 (5)	Branchlets glabrous; leaf blades 3–7 cm, glabrous on both surfaces, margin crenate to doubly serrate; flowers bisexual, dark purple-red.		5 S. purpurea
+	Branchlets pubescent or subglabrous; leaf blades 2–4 cm, slightly pubescent on veins on both surfaces or glabrous adaxially, margin sharply serrate or doubly serrate; flowers usually ± unisexual, pink, rarely white.		6 S. bella
7 (5)	Leaf blades glabrous on both surfaces; inflorescences to 5 × 5.5 cm.		4 S. hayatana
+	Leaf blades pubescent on both surfaces or only on veins; inflorescences 6–12 × 4–14 cm.		(8)
8 (7)	Branchlets glabrous or pubescent when young; leaf blades doubly incised serrate at margin, rarely singly serrate, apex acute to acuminate.		2 S. japonica
+	Branchlets densely yellow pubescent when young; leaf blades doubly serrate at margin, apex acute.		3 S. formosana
9 (3)	Buds obtuse at apex, with several exterior scales.		(10)
+	Buds acute to acuminate at apex, with 2 exterior scales.		(19)
10 (9)	Stamens 2–3 × as long as petals.		8 S. miyabei
+	Stamens shorter than to nearly equaling petals.		(11)
11 (10)	Leaf blade margin with a few teeth above middle or near apex.		(12)
+	Leaf blade margin entire, rarely with a few teeth apically.		(15)
12 (11)	Follicles glabrous or hairy only along adaxial suture.		11 S. sargentiana
+	Follicles hairy.		(13)
13 (12)	Branchlets angled; leaf blades tomentose abaxially; pedicels 1–2 mm.		10 S. schochiana
+	Branchlets terete; leaf blades densely thinly villous abaxially; pedicels 4–8 mm.		(14)
14 (13)	Bracts 2–4 mm; follicles thinly villous.		9 S. henryi
+	Bracts 4–6 mm; follicles densely pubescent.		12 S. wilsonii
15 (11)	Leaf blades glabrous on both surfaces or thinly villous along margin; branchlets angled.		16 S. schneideriana
+	Leaf blades softly hairy abaxially or on both surfaces; branchlets terete.		(16)
16 (15)	Follicles glabrous.		15 S. veitchii
+	Follicles softly hairy.		(17)
17 (16)	Inflorescences glabrous; leaf blades glabrous or sparsely pubescent only on veins abaxially.		14 S. ovalis
+	Inflorescences and both surfaces of leaf blades softly hairy.		(18)
18 (17)	Inflorescences sparsely villous; leaf blades 10–30 × 5–10 mm, villous on both surfaces, adaxially without papillae, margin entire or apically with a few teeth.		12 S. wilsonii
+	Inflorescences densely and thinly pubescent; leaf blades 6–11 × 4–7 mm, thinly pubescent on both surfaces when young, later glabrescent, adaxially with papillae, margin entire.		13 S. teretiuscula
19 (9)	Leaf blade margin entire or with a few teeth above middle.		(20)
+	Leaf blade margin singly or doubly serrate, sometimes incised.		(23)
20 (19)	Branchlets cylindric or slightly angled; inflorescences glabrous.		28 S. uratensis
+	Branchlets angled; inflorescences puberulous to pubescent.		(21)
21 (20)	Flowers red; leaf blades 0.8–1.2 cm, sometimes lobed apically; follicles usually glabrous, rarely puberulous on adaxial suture.		25 S. arcuata
+	Flowers white; leaf blades 1–3 cm, not lobed apically; follicles pubescent.		(22)
22 (21)	Leaf blades ovate or obovate to obovate-lanceolate, 1–2 cm, pubescent abaxially, margin obtusely 3–5-dentate above middle.		26 S. canescens
+	Leaf blades oblong to ovate- or obovate-oblong, 1.5–3 cm, glabrous on both surfaces, margin often entire.		27 S. trichocarpa
23 (19)	Buds small, shorter than petioles.		(24)
+	Buds usually large, nearly equaling or longer than petioles, very rarely shorter.		(27)
24 (23)	Shrubs to 3 m tall; leaf blades abaxially slightly hairy on veins.		(25)
+	Shrubs to 0.5 m tall; leaf blades abaxially glabrous.		(26)
25 (24)	Leaf blades elliptic to elliptic-ovate, margin sharply singly serrate; inflorescences and hypanthium abaxially softly hairy.		17 S. teniana
+	Leaf blades ovate to elliptic-ovate, margin obtusely singly or doubly serrate; inflorescences and hypanthium abaxially glabrous.		18 S. hingshanensis
26 (24)	Leaf blades ovate or rhomboid-ovate, margin sharply singly serrate above middle; flowers white; ovary basally slightly pubescent.		19 S. morrisonicola
+	Leaf blades ovate, margin doubly serrate; flowers pink; ovary glabrous.		20 S. kweichowensis
27 (23)	Inflorescences and follicles subglabrous or pilose.		24 S. longigemmis
+	Inflorescences and follicles densely softly hairy.		(28)
28 (27)	Buds glabrous; leaf blades abaxially pubescent.		23 S. rosthornii
+	Buds densely tomentose-villous; leaf blades abaxially sericeous-villous, sometimes glabrescent.		(29)
29 (28)	Petioles 3–5 mm; leaf blades ovate or ovate-lanceolate, abaxially sericeous-villous, later glabrescent, margin often entire.		21 S. velutina
+	Petioles 6–10 mm; leaf blades broadly ovate or rhombic-ovate, abaxially sericeous-villous, not glabrescent, margin lobed.		22 S. lobulata
30 (1)	Flowers in sessile umbels, with or without leaves at base.		(31)
+	Flowers in pedunculate umbels or umbel-like racemes, with clustered leaves at base.		(42)
31 (30)	Leaf blade margin entire or with a few crenate teeth near apex; stamens equaling petals or nearly so.		(32)
+	Leaf blade margin serrate or slightly lobed; stamens shorter than petals.		(36)
32 (31)	Branchlets conspicuously angled; flowers pinkish.		66 S. calcicola
+	Branchlets terete; flowers white.		(33)
33 (32)	Leaf blades on sterile branches usually flabellate, ± as wide as long.		(34)
+	Leaf blades on sterile branches not flabellate, longer than wide, apex acute or obtuse.		(35)
34 (33)	Branchlets glabrous; leaf blades abaxially glabrous, with glaucous bloom.		69 S. compsophylla
+	Branchlets densely pubescent, later glabrescent; leaf blades abaxially densely pubescent.		70 S. aquilegiifolia
35 (33)	Branchlets glabrous or puberulent; leaf blades 15–20 × 5–7 mm; follicles glabrous.		67 S. hypericifolia
+	Branchlets densely pubescent, later glabrescent; leaf blades 4–14 × 3–5 mm; follicles pubescent.		68 S. hailarensis
36 (31)	Leaf blade margin sharply serrulate.		(37)
+	Leaf blade margin coarsely serrate.		(38)
37 (36)	Leaf blades ovate to oblong-lanceolate, abaxially pubescent; pedicels 10–24 mm, pubescent.		59 S. prunifolia
+	Leaf blades linear-lanceolate, abaxially glabrous; pedicels 6–10 mm, glabrous.		60 S. thunbergii
38 (36)	Leaf blades glabrous on both surfaces.		65 S. kwangsiensis
+	Leaf blades pubescent on both surfaces or glabrous adaxially when old.		(39)
39 (38)	Branchlets terete, pubescent or tomentose; pedicels and hypanthium abaxially glabrous.		(40)
+	Branchlets prominently angled, pubescent or villous; pedicels and hypanthium abaxially hairy.		(41)
40 (39)	Branchlets densely tomentose; leaf blade margin usually 3-lobed, with a few large, obtuse teeth above middle, base cuneate or broadly so.		61 S. martini
+	Branchlets pubescent; leaf blade margin not lobed, with many large, crenate teeth above base, base subrounded.		62 S. cavaleriei
41 (39)	Branchlets and buds appressed villous; pedicels and hypanthium abaxially villous when young; follicles glabrous or slightly pilose on adaxial suture.		63 S. daochengensis
+	Branchlets and buds densely pubescent; pedicels, hypanthium abaxially, and follicles pubescent.		64 S. muliensis
42 (30)	Buds with 2 exterior scales.		(43)
+	Buds with several exterior scales.		(46)
43 (42)	Leaf blade margin serrate; stamens longer than petals; sepals reflexed in fruit.		(44)
+	Leaf blade margin entire or apically crenate-serrate; stamens subequaling petals; sepals erect or spreading in fruit.		(45)
44 (43)	Leaf blades oblong-elliptic to oblong-ovate, margin sharply serrate above middle or near apex; petioles 2–5 mm; stamens ca. 20.		55 S. flexuosa
+	Leaf blades broadly ovate, margin minutely serrate or doubly serrate; petioles 4–7 mm; stamens 35–50.		56 S. chamaedryfolia
45 (43)	Branchlets, leaf blades, and inflorescences glabrous; follicles glabrous or slightly hairy on adaxial suture.		57 S. mongolica
+	Branchlets, leaf blades, and inflorescences villous; follicles pubescent.		58 S. mollifolia
46 (42)	Leaf blade margin entire or apically crenate-serrate.		(47)
+	Leaf blade margin serrate or incised, sometimes lobed.		(55)
47 (46)	Leaf blades abaxially hairy; follicles hairy; sepals reflexed in fruit.		(48)
+	Leaf blades abaxially glabrous (pubescent in S. xizangensis); follicles glabrous or pilose on adaxial suture; sepals erect, spreading, or reflexed in fruit.		(51)
48 (47)	Leaf blade margin with a few obtuse teeth above middle; racemes dense.		49 S. tarokoensis
+	Leaf blade margin entire or on sterile shoots with sharp teeth apically; racemes lax.		(49)
49 (48)	Branchlets glabrous or subglabrous; leaf blades abaxially glabrous or slightly pubescent in vein axils.		48 S. media
+	Branchlets densely villous; leaf blades abaxially densely long sericeous.		(50)
50 (49)	Shrubs erect, to 2 m; leaf blades ovate-elliptic or elliptic, 1.5–4.5 cm; inflorescences 15–30-flowered; stamens longer than petals.		46 S. sericea
+	Shrubs prostrate; leaf blades broadly ovate, 0.8–1.5 cm; inflorescences 7–15-flowered; stamens slightly shorter than petals.		47 S. prostrata
51 (47)	Branchlets terete, glabrous; sepals reflexed.		54 S. dahurica
+	Branchlets angled, pubescent; sepals erect or slightly spreading.		(52)
52 (51)	Leaf blades 2–4 mm wide; veins inconspicuous.		(53)
+	Leaf blades 4–9 mm wide, ± conspicuously 3-veined at base.		(54)
53 (52)	Flowers white; styles subterminal, divergent.		50 S. alpina
+	Flowers pink-red; styles abaxial, suberect.		51 S. xizangensis
54 (52)	Inflorescences 2–4 cm; styles terminal, divergent.		52 S. myrtilloides
+	Inflorescences 1–1.5 cm; styles abaxial.		53 S. ningshiaensis
55 (46)	Stamens longer than or rarely subequaling petals; flowers in umbel-like racemes.		(56)
+	Stamens shorter than or subequaling petals; flowers in umbels.		(61)
56 (55)	Follicles pubescent or hirsute; sepals erect in fruit.		(57)
+	Follicles glabrous or subglabrous; sepals reflexed in fruit.		(59)
57 (56)	Pedicels and hypanthium abaxially pubescent; leaf blades abaxially pubescent, margin lobed.		40 S. sublobata
+	Pedicels and hypanthium abaxially glabrous; leaf blades abaxially pubescent on veins or in vein axils, margin not lobed.		(58)
58 (57)	Leaf blades oblong-elliptic to lanceolate-elliptic, abaxially pubescent in vein axils, base cuneate, margin irregularly incised serrate, sometimes doubly serrate above middle.		41 S. elegans
+	Leaf blades triangular-ovate or lanceolate-ovate, abaxially pubescent on veins, base truncate, rarely subrounded, margin doubly serrate except near base.		42 S. anomala
59 (56)	Leaf blades ovate to elliptic-ovate, glabrous or abaxially with tufted hairs in vein axils, margin singly serrate, leaves on sterile shoots often incised doubly serrate.		43 S. laeta
+	Leaf blades oblong or ovate, margin with a few coarse teeth.		(60)
60 (59)	Leaf blades sericeous-villous on both surfaces, margin with 3–7 large, acute teeth on each side above middle; inflorescences 12–20-flowered; flowers 8–10 mm in diam.		44 S. papillosa
+	Leaf blades glabrous on both surfaces, margin with 3–5 inconspicuous, triangular, obtuse teeth on each side above middle; inflorescences 5–10-flowered; flowers 10–12 mm in diam.		45 S. lichiangensis
61 (55)	Leaf blades, inflorescences, and follicles glabrous.		(62)
+	Leaf blades hairy abaxially.		(65)
62 (61)	Leaf blade apex acute.		(63)
+	Leaf blade apex obtuse.		(64)
63 (62)	Leaf blade rhombic-lanceolate to rhombic-oblong, pinnately veined, margin serrate above middle.		36 S. cantoniensis
+	Leaf blade rhombic-ovate, inconspicuously 3-veined or pinnately veined, margin usually 3-lobed, incised doubly serrate.		37 S. ×vanhouttei
64 (62)	Leaf blades suborbicular, 3–5-veined, base rounded to subcordate, rarely cuneate, margin with a few crenate teeth above middle, apex usually 3-lobed.		38 S. trilobata
+	Leaf blades rhombic-ovate to obovate, inconspicuously 3-veined or pinnately veined, base cuneate, margin with a few crenate, incised teeth or 3–5 lobes above middle.		39 S. blumei
65 (61)	Inflorescences glabrous; follicles glabrous except on adaxial suture.		35 S. pubescens
+	Inflorescences and follicles hairy.		(66)
66 (65)	Leaf blades glabrous adaxially, pilose or subglabrous abaxially.		34 S. siccanea
+	Leaf blades pilose adaxially.		(67)
67 (66)	Leaf blades pubescent abaxially.		(68)
+	Leaf blades tomentose abaxially.		(69)
68 (67)	Leaf blades abaxially sericeous-pubescent, margin coarsely obtusely dentate, apex usually 3-lobed; inflorescences 2–3 cm in diam.; pedicels 6–10 mm.		29 S. nishimurae
+	Leaf blades abaxially sparsely pubescent, margin obtusely or sharply serrate above middle or near apex, apex not 3-lobed; inflorescences 4–5 cm in diam.; pedicels 12–22 mm.		30 S. hirsuta
69 (67)	Sepals ovate-lanceolate; leaf blades abaxially densely yellow tomentose, deeply sharply incised serrate.		31 S. chinensis
+	Sepals triangular to ovate-triangular; leaf blades abaxially densely white tomentose, shallowly obtusely serrate.		(70)
70 (69)	Leaf blades rhombic-ovate, 2–4.5 cm, margin obtusely incised serrate or lobed, apex acute, rarely obtuse.		32 S. dasyantha
+	Leaf blades ovate to obovate, 1–2 cm, margin ± obtusely serrate or doubly serrate, apex obtuse or slightly 3-lobed.		33 S. yunnanensis