1	Perianth in female flowers symmetrical; sepals and petals each in whorls of 3 or 4; male and female flowers similar; main root cylindrical and fleshy or roots not enlarged		(2)
+	Perianth in female flowers asymmetrical, occasionally also symmetrical within same inflorescence; sepal 1(-3), scalelike; petals 2(or 3); rootstock tuberous, often huge, often partly above ground (S. subg. Tuberiphania)		(12)
2 (1)	Inflorescences mostly slender axillary thyrses; male flowers with sepals usually in 1 whorl of 4; endocarp abaxially bearing 4 rows of ornamentation, 2 inner rows columnar and very prominent; condyle usually not perforate; [leaf blade abaxially densely pubescent]; main root cylindrical, fleshy (S. subg. Botryodiscia).		11 S. tetrandra
+	Inflorescences umbelliform cymes, simple or compound, sometimes forming a terminal thyrse by reduction of apical leaves; male flowers with sepals in 2 whorls each of 3 or 4; endocarp abaxially bearing 2, 4, or 10 or more rows of ornamentation; [leaf blade abaxially often glabrous]; roots not tuberous and fleshy (S. subg. Stephania)		(3)
3 (2)	Cymelets and flowers sessile or nearly so, tightly condensed into compound umbelliform cymes; endocarp abaxially ornamented with rows of 10 or slightly more (S. sect. Stephania)		(4)
+	Cymelets and flowers conspicuously pedicellate, loose, in simple, seldom compound, umbelliform cymes; endocarp abaxially ornamented with rows of 2 or 4 (S. sect. Laxithyrsa)		(5)
4 (3)	Leaf blade ca. as long as wide, abaxial surface glaucous.		9 S. japonica
+	Leaf blade longer than wide, abaxial surface usually green.		10 S. longa
5 (3)	Inflorescence compound with umbel-like cymelets themselves in secondary umbels; condyle perforate		(6)
+	Inflorescence simple with cymelets borne directly on peduncle; endocarp abaxially ornamented with 2 or 4 rows each of less than 10 transverse ridges; condyle perforate or not		(7)
6 (5)	Endocarp 10-12 mm, abaxially with 4 rows of columnar processes with ends swollen; palmate veins thick, conspicuously raised abaxially.		7 S. merrillii
+	Endocarp 4-5 mm, abaxially ornamented with 2 rows of transverse ridges; palmate veins slender, slightly raised abaxially.		8 S. delavayi
7 (5)	Sepals apically mucronate or acutely acuminate, never caudate		(8)
+	Sepals conspicuously caudate at apex		(10)
8 (7)	Condyle perforate.		3 S. gracilenta
+	Condyle not perforate		(9)
9 (8)	Leaf blade broadly ovate-triangular, usually wider than long.		1 S. herbacea
+	Leaf blade narrowly triangular, longer than wide.		2 S. elegans
10 (7)	Leaf blade margin repand dentate.		6 S. chingtungensis
+	Leaf blade margin entire		(11)
11 (10)	Petiole inserted 1-2 mm from base of leaf blade; leaf blade subpeltate, ovate- triangular or broadly triangular to subtriangular, longer than wide; condyle not perforate.		4 S. subpeltata
+	Petiole inserted ca. 10 mm from base of leaf blade; leaf blade conspicuously peltate, triangular, ca. as long as wide; condyle perforate.		5 S. sutchuenensis
12 (1)	Endocarp abaxially ornamented with transverse ridges; male and female inflorescences ± similar (S. sect. Transcoctula)		(13)
+	Endocarp abaxially ornamented with rows of columnar tubercles; male and female inflorescences ± different (S. sect. Tuberiphania)		(19)
13 (12)	Peduncle of inflorescence with disciform receptacle at apex, both male and female inflorescences capitate.		18 S. cephalantha
+	Peduncle of inflorescence without disciform receptacle at apex		(14)
14 (13)	Leaves with margin dentate; branches and leaves containing red juice.		17 S. dentifolia
+	Leaves entire or horned; branches and leaves not containing red juice		(15)
15 (14)	Endocarp abaxially ornamented with rows of 20-25 transverse ridges; condyle perforate; petals of male flowers with granular glands.		16 S. glabra
+	Endocarp abaxially ornamented with rows of less than 20 transverse ridges; condyle not perforate; petals of male flowers with or without glands		(16)
16 (15)	Inflorescence with simple umbelliform cymes; flowers purple; male petals not adaxially glandular; leaf blade usually less than 7(-9) cm long and wide		(17)
+	Inflorescence with compound umbelliform cymes; flowers greenish yellow; leaf blade usually more than 10 cm long and wide		(18)
17 (16)	Male sepals ovate, 1.3-1.6 mm; leaves abaxially glabrous; peduncle 1-4 cm.		12 S. epigaea
+	Male sepals rounded, ca. 0.5 mm in diam.; leaves abaxially whitish puberulent; peduncle 0.5-1.5 cm.		13 S. brevipedunculata
18 (16)	Male petal with margin extended, with 2 adaxial glands.		14 S. sinica
+	Male petal with margin involute, without adaxial glands.		15 S. intermedia
19 (12)	Endocarp tubercles apically obtuse, or slightly swollen and capitate; condyle perforate		(20)
+	Endocarp tubercles abaxially with columnar ornamentation apically curved		(27)
20 (19)	Peduncles and umbellet pedicels not bracteate and bracteolate or occasionally with 1 or 2 reduced bracts; petals with verruculose or tuberculate processes inside		(21)
+	Peduncles and umbellet pedicels bracteate and bracteolate; petals with or without processes inside		(22)
21 (20)	Sepals ca. 3 mm, abaxially densely papillate; leaf blade margin horned or horned dentate; fruit unknown.		25 S. macrantha
+	Sepals ca. 2 mm, abaxially not papillate; leaf blade margin entire; fruiting pedicels fleshy.		26 S. officinarum
22 (20)	Petals of male flowers with lateral margins involute		(23)
+	Petals of male flowers with lateral margins not involute, with 2 large glands inside		(24)
23 (22)	Endocarp 5-6 mm; male petals abaxially conspicuously depressed, with many verruculose or lobed processes.		19 S. viridiflavens
+	Endocarp 9-10 mm; male petals abaxially not depressed, without verruculose processes.		20 S. brachyandra
24 (22)	Sepals and petals purple; branches and leaves containing purplish red juice.		21 S. yunnanensis
+	Sepals green; petals orangish yellow; branches and leaves not containing red juice		(25)
25 (24)	Branches and leaves black when dried; sepal margins involute when flower blooming.		22 S. lincangensis
+	Branches and leaves not black when dried; sepal margins not involute		(26)
26 (25)	Fruiting pedicel not fleshy; endocarp with columnar tubercles apically obtuse.		23 S. kuinanensis
+	Fruiting pedicel fleshy; endocarp with columnar tubercles apically swollen and capitate.		24 S. dicentrinifera
27 (19)	Petals of male flowers with 2 large glands inside		(28)
+	Petals in male flowers without glands inside		(31)
28 (27)	Condyle not perforate.		37 S. miyiensis
+	Condyle perforate		(29)
29 (28)	Fruiting pedicel not fleshy; condyle perforate in middle.		34 S. kwangsiensis
+	Fruiting pedicel fleshy; condyle perforate laterally		(30)
30 (29)	Sepals of male flowers free without conspicuous claw; peduncle apically bracteate.		35 S. excentrica
+	Sepals of male flowers connate, inner whorl with conspicuous claw.		36 S. ebracteata
31 (27)	Fruiting pedicel fleshy		(32)
+	Fruiting pedicel not fleshy		(33)
32 (31)	Branches and leaves containing red juice; sepals and petals purple; endocarp with columnar ornamentation short, apically slightly curved and hooklike; leaf blade less than 10 cm.		32 S. succifera
+	Branches and leaves containing light yellow or white juice; sepals green; petals orange; endocarp with columnar ornamentation conspicuously curved and hooklike; leaf blade 10-16 cm.		33 S. hainanensis
33 (31)	Petals of male flowers with margin conspicuously thickened; sepals abaxially hispidulous or pubescent.		27 S. dolichopoda
+	Petals of male flowers with margin not thickened; sepals abaxially not glabrous		(34)
34 (33)	Branches and leaves without red juice; sepals green; petals yellow or orange		(35)
+	Branches and leaves with red juice; sepals and petals purple		(36)
35 (34)	Endocarp bearing columnar ornamentation, each row of 18-20; leaves more than 10 cm.		28 S. mashanica
+	Endocarp bearing columnar ornamentation, each row of 20-25; leaves usually less than 10 cm.		29 S. micrantha
36 (34)	Umbellet pedicels transparent when dry; sepals of male flowers with margin membranous; petiole rarely less than 2 × as long as leaf blade.		30 S. longipes
+	Umbellet pedicels not transparent when dry; sepals of male flowers with margin not membranous; petiole subequal to or slightly longer than leaf blade.		31 S. dielsiana