1	Plants erect, rarely prostrate; leaves usually spurless (shortly spurred in S. leptophyllum).		(2)
+	Plants subprostrate, ascending, or decumbent; leaves usually spurred; sepals spurred, rarely spurless.		(8)
2 (1)	Pseudopetiole conspicuous.		(3)
+	Pseudopetiole inconspicuous, leaves tapered toward base.		(5)
3 (2)	Carpels 4; follicles many seeded		75 S. tetractinum
+	Carpels 5; follicles 1-3-seeded.		(4)
4 (3)	Bracts orbicular to suborbicular; leaves rhombic-elliptic, 3-6 cm, apex attenuate or retuse to emarginate		73 S. oligospermum
+	Bracts linear-spatulate; leaves ovate to suborbicular, 1.5-3 cm, apex rounded		74 S. wilsonii
5 (2)	Carpels and nectar scales 3; seeds few.		(6)
+	Carpels and nectar scales 4; seeds numerous.		(7)
6 (5)	Leaves verticillate or opposite, spatulate-oblong		76 S. triactina
+	Leaves alternate, rarely verticillate, oblanceolate to linear-lanceolate		77 S. leptophyllum
7 (5)	Leaves narrowly oblanceolate, 1-2.5 cm; sepals triangular to narrowly elliptic; petals 4-4.5 mm, apex shortly mucronate		78 S. hakonense
+	Leaves oblanceolate, 2.5-4.5 cm; sepals narrowly triangular; petals ca. 7 mm, apex acute		79 S. dongzhiense
8 (1)	Rootstock with root shoots or white, globose latent bulbs.		(9)
+	Rootstock absent, roots slender.		(12)
9 (8)	Rootstock ascending, root shoots present.		(10)
+	Rootstock slender, white, globose latent bulbs present.		(11)
10 (9)	Plants 5-20 cm tall; leaves spatulate to broadly obovate, 12-20 mm		80 S. leucocarpum
+	Plants ca. 7 cm tall; leaves ovate, 3-4 mm		81 S. wenchuanense
11 (9)	Leaves alternate, 3-15 × ca. 2 mm; sepals 1.5-7 mm		82 S. tianmushanense
+	Leaves opposite at base of stem, 4-verticillate at middle, alternate at apex, 12-30 × 1-2 mm; sepals 2-2.5 mm		83 S. latentibulbosum
12 (8)	Sepals equaling or longer than petals or, if shorter than the petals, all sepals equal.		(13)
+	Sepals shorter than petals or, if longer than petals, sepals unequal.		(14)
13 (12)	Plants annual; petals triangular, apex acute		84 S. woronowii
+	Plants perennial; petals oblong-ovate, apex long mucronate		85 S. multicaule
14 (12)	Plants suffrutescent, tufted; sepals 1/4-1/3 as long as petals		86 S. polytrichoides
+	Plants mostly not tufted, leathery; sepals to 1/2 as long as petals.		(15)
15 (14)	Leaves usually verticillate (sometimes opposite or less often alternate in S. erythrospermum).		(16)
+	Leaves usually alternate or opposite (verticillate or verticillate and alternate in S. cryptomerioides, S. dimorphophyllum, and S. subtile).		(24)
16 (15)	Leaves usually 1.5-3 cm.		(17)
+	Leaves 0.5-1.4 cm.		(19)
17 (16)	Leaves oblanceolate to oblong		117 S. sarmentosum
+	Leaves linear to linear-oblanceolate.		(18)
18 (17)	Petal apex not mucronate		118 S. lineare
+	Petal apex long mucronate		119 S. grammophyllum
19 (16)	Leaves opposite or 3- or 4-verticillate.		(20)
+	Leaves 4- or 5-verticillate.		(22)
20 (19)	Plants annual; sterile stems absent		113 S. erythrospermum
+	Plants perennial; sterile stems present.		(21)
21 (20)	Leaves 3-verticillate and linear on flowering stems, 3-verticillate and obovate on sterile stems; sepals linear-obovate		111 S. jiulungshanense
+	Leaves on flowering stems and sterile stems 3- or 4-verticillate, broadly linear to lanceolate; sepals broadly linear to suboblong		112 S. onychopetalum
22 (19)	Leaves 4- or 5-verticillate, differently shaped basally and apically on stem		116 S. kiangnanense
+	Leaves 4-verticillate, similarly shaped basally and apically on stem.		(23)
23 (22)	Leaf apex acute; nectar scales spatulate-oblong; anthers blackish		114 S. phyllanthum
+	Leaf apex obtuse; nectar scales oblong-cuneate; anthers not blackish		115 S. yvesii
24 (15)	Leaves verticillate and alternate apically on stems, verticillate basally on old stems		87 S. dimorphophyllum
+	Leaves alternate or opposite (verticillate apically on stems in S. cryptomerioides and occasionally in S. subtile).		(25)
25 (24)	Leaves usually conspicuously pseudopetiolate.		(26)
+	Leaves inconspicuously pseudopetiolate.		(27)
26 (25)	Leaf base spurred; sepals equal; bracts very large, resembling stem leaves		120 S. concarpum
+	Leaf base spurless; sepals unequal; bracts very small, mostly obscure		121 S. engleri
27 (25)	Leaves opposite (sometimes alternate or less often verticillate in S. actinocarpum).		(28)
+	Leaves alternate (opposite basally on stems in S. bulbiferum and occasionally in S. formosanum).		(31)
28 (27)	Stems 3-7 cm		110 S. baileyi
+	Stems 10-25 cm.		(29)
29 (28)	Leaf apex emarginate		108 S. emarginatum
+	Leaf apex truncate.		(30)
30 (29)	Stems erect; carpels suboblong to ovoid, ca. 2.5 mm; follicles horizontally spreading		107 S. actinocarpum
+	Stems basally prostrate; carpels lanceolate, ca. 5 mm; follicles obliquely spreading		109 S. makinoi
31 (27)	Plants pubescent throughout.		(32)
+	Plants glabrous throughout.		(33)
32 (31)	Leaves obovate; sepals ovate		88 S. giajae
+	Leaves spatulate; sepals spatulate		89 S. lungtsuanense
33 (31)	Bulbils usually present in leaf axils		90 S. bulbiferum
+	Bulbils absent in leaf axils.		(34)
34 (33)	Sterile stems absent.		(35)
+	Sterile stems present.		(41)
35 (34)	Sepals wider at base than at middle.		(36)
+	Sepals narrower at base than at middle.		(37)
36 (35)	Sepals triangular		100 S. microsepalum
+	Sepals linear-ovate		101 S. hangzhouense
37 (35)	Leaves 0.6-1 cm; seeds minutely papillate or reticulate.		(38)
+	Leaves 1.2-3 cm; seeds smooth.		(39)
38 (37)	Leaves ca. 6 × 1.5 mm; seeds reticulate		102 S. morrisonense
+	Leaves 6-10 × 3-5 mm; seeds papillate		103 S. nokoense
39 (37)	Flowering stems branched from base		104 S. formosanum
+	Flowering stems simple, rarely apically branched.		(40)
40 (39)	Leaves oblanceolate to narrowly elliptic-lanceolate; sepals 1.5-3 × ca. 0.5 mm; seeds yellow		105 S. parvisepalum
+	Leaves linear-cuneate, spatulate, or obovate; sepals 3-5 × 1-1.5 mm; seeds brown		106 S. alfredii
41 (34)	Leaves of flowering stems terete or ± flat.		(42)
+	Leaves of flowering stems flat.		(43)
42 (41)	Leaves of flowering stems very crowded, 0.3-0.5 cm; sepals to 3 mm		91 S. uniflorum
+	Leaves of flowering stems ± remote, 7-10 cm; sepals to 4 mm		92 S. japonicum
43 (41)	Leaves of flowering stems minutely papillate on distal margin; sepals minutely papillate; follicles stellately subhorizontally spreading		93 S. planifolium
+	Leaves of flowering stems not minutely papillate on margin; sepals not minutely papillate; follicles stellately divaricate but not horizontally spreading.		(44)
44 (43)	Sepals spurless; leaves of sterile stems rosulate		95 S. sekiteiense
+	Sepals spurred; leaves of sterile stems not rosulate.		(45)
45 (44)	Leaves opposite or 3-6-verticillate basally on stem or verticillate and crowded apically on stem.		(46)
+	Leaves all alternate.		(47)
46 (45)	Leaves opposite or 3-6-verticillate basally on stem		96 S. subtile
+	Leaves verticillate and crowded apically on stem		99 S. cryptomerioides
47 (45)	Sepals subequal; seeds smooth		94 S. hengduanense
+	Sepals unequal; seeds papillate.		(48)
48 (47)	Petals narrowly elliptic-lanceolate		97 S. tosaense
+	Petals oblong-lanceolate		98 S. nanchuanense