1	Seeds subquadrangular, obovate-triangular, oblong, or 4-angled, 3-loculed, turgid, surrounded by thick ridges		(2)
+	Seeds elliptic, ovate-elliptic, or oblong, 1-loculed, compressed or turgid		(6)
2 (1)	Seeds 4-angled, with narrow middle ridge, 2 lateral locules broad; leaf blade abaxially glabrous or puberulent on veins.		33 T. tetragonosperma
+	Seeds subquadrangular, obovate-triangular, or oblong, 2 lateral locules narrow; leaf blade abaxially densely pubescent		(3)
3 (2)	Leaves unlobed or irregularly shortly 3-lobed		(4)
+	Leaves usually 3-7-lobed		(5)
4 (3)	Leaf blade ovate, thinly membranous, unlobed; fruit ovoid, smooth, glabrous.		30 T. baviensis
+	Leaf blade broadly cordate, papery, unlobed or shortly 3-lobed; fruit ovoid-oblong or oblong, densely white villous.		31 T. trichocarpa
5 (3)	Bracts lanceolate or oblanceolate, ca. 1.6 × 0.5-0.6 cm, margin triangular-dentate; leaves adaxially glabrous or puberulent.		29 T. pilosa
+	Bracts linear-lanceolate, 2-3 mm, entire; leaves adaxially tomentose.		32 T. cucumeroides
6 (1)	Plants monoecious or dioecious; male flowers in racemes, bract very small, less than 5 mm; seed margin undulate-dentate		(7)
+	Plants dioecious; male flowers solitary or in racemes or rarely in a panicle; bracts 1-6.5 cm or rarely ca. 5 mm; seed margin crenellate		(9)
7 (6)	Plants dioecious; bracts absent or ca. 5 mm; fruit cylindric, ca. 20 × 7 cm.		3 T. dafangensis
+	Plants monoecious; bracts 1-3 mm or very small or absent; fruit cylindric and 100-200 cm, or ovoid-oblong and 5-7 cm		(8)
8 (7)	Bracts 1-3 mm; fruit cylindric, 100-200 × 3-4 cm; leaf lobes obovate.		1 T. anguina
+	Bracts absent or very small; fruit ovoid-oblong, 5-7 × 2.5-3.5 cm; leaf lobes rhombic or triangular.		2 T. cucumerina
9 (6)	Leaves simple, leaf blade smooth on both surfaces; bract in male flower spreading, margin entire or sinuate-dentate		(10)
+	Leaves simple or 3-5-foliolate; leaf blade white punctate; bracts large, conspicuous, margin dentate		(21)
10 (9)	Male racemes densely villous		(11)
+	Male racemes slightly hairy or villous, one peduncle 1-flowered, other bearing a raceme		(14)
11 (10)	Leaves leathery, unlobed, leaf blade pubescent on veins.		13 T. reticulinervis
+	Leaves papery, unlobed or 3-5-lobed		(12)
12 (11)	Leaves unlobed; seeds subovate, 10-13 × 7-8 mm, margin undulate.		11 T. kerrii
+	Leaves 3-5-lobed or deeply lobed		(13)
13 (12)	Leaf blade abaxially densely white sericeous; male flowers solitary, densely white sericeous.		12 T. sericeifolia
+	Leaf blade abaxially densely brownish villous; male raceme densely brownish villous.		20 T. villosa
14 (10)	Leaves ovate or ovate-oblong, subleathery or leathery, unlobed or rarely 3-lobed		(15)
+	Leaves ovate-cordate or orbicular-cordate, papery, 3-9-lobed to middle or nearly to base		(17)
15 (14)	Leaf blade papery, base cordate; fruit oblong, 7-10 × 6-7 cm.		10 T. homophylla
+	Leaf blade subleathery or leathery		(16)
16 (15)	Leaf blade subleathery, unlobed, base rounded; fruit globose, ca. 7 cm in diam.		8 T. smilacifolia
+	Leaf blade leathery, unlobed or shortly to deeply 2- or 3-lobed, base truncate; fruit oblong, 12-18 × 5-10 cm.		9 T. truncata
17 (14)	Male flowers solitary, smaller than 3 cm in diam.; calyx tube narrowly campanulate.		7 T. hylonoma
+	Male flowers in raceme; flowers larger than 3 cm in diam.; calyx tube narrowly funnelform or cylindric		(18)
18 (17)	Leaves usually 3-5(-7)-lobed		(19)
+	Leaves deeply 3-7-lobed usually up to base		(20)
19 (18)	Bracts in male flowers ca. 3 cm, margin entire; calyx tube funnelform, ca. 3 cm, segments linear-lanceolate, 10-15 × 1.5-2.5 mm; leaves ovate-cordate.		4 T. jinggangshanica
+	Bracts in male flowers less than 2.5 cm, margin sinuate-dentate; calyx tube cylindric, dilated at apex, 20-40 × ca. 10 mm; leaves suborbicular.		5 T. kirilowii
20 (18)	Leaf lobes rhombic; fruiting peduncle 12-16.5 cm.		6 T. mianyangensis
+	Leaf lobes linear-lanceolate or oblanceolate; fruiting peduncle 4.5-8 cm.		14 T. rosthornii
21 (9)	Leaves 3-5-foliolate; bracts rhombic-lanceolate		(22)
+	Leaves simple; bracts broadly ovate or oblong		(23)
22 (21)	Leaflets remotely denticulate at margin.		27 T. pedata
+	Leaflets entire at margin.		28 T. quinquefolia
23 (21)	Flowers red, pale red, or purple		(24)
+	Flowers white		(27)
24 (23)	Seeds ovoid, turgid.		22 T. dunniana
+	Seeds oblong or oblong-ovate, compressed		(25)
25 (24)	Seeds oblong, truncate at both ends, ca. 18 mm; flowers purple; calyx tube ca. 2.5 cm, segments linear; fruit orange-yellow.		25 T. rugatisemina
+	Seeds oblong-ovate, 10-15 mm; flowers pale red		(26)
26 (25)	Leaf blade deeply (3-)5(-7)-lobed; calyx tube 4-6 cm, segments ovate-lanceolate, denticulate; fruit red.		23 T. rubriflos
+	Leaf blade shortly 5-7-lobed or lobed to middle; calyx tube ca. 4 cm, segments narrowly lanceolate, entire; fruit orange-red.		24 T. subrosea
27 (23)	Bracts entire		(28)
+	Bract margin dentate or lacerate		(29)
28 (27)	Bracts ovate, 3.5-4.3 × ca. 2.5 cm, with 2 rows of brownish puncta beside main vein; calyx segments 2-3 cm, margin sharply 2- or 3-lobed; seeds triangular-ovate; leaves membranous, abaxially glabrous, adaxially punctate, petiole 5-11 cm.		18 T. quinquangulata
+	Bracts oblong, ca. 4 × 1-1.5 cm; calyx segments ca. 1 cm, entire; seeds subquadrangular; leaves papery, hirsute, petiole 14-17 cm.		19 T. cordata
29 (27)	Leaves leathery		(30)
+	Leaves membranous or papery		(31)
30 (29)	Bracts suborbicular, margin lacerate; calyx segments narrowly ovate, margin laciniate; leaves suborbicular.		17 T. lepiniana
+	Bracts obovate-oblong, margin dentate; calyx segments narrowly lanceolate, margin dentate; leaves ovate-cordate.		26 T. tricuspidata
31 (29)	Leaves papery.		21 T. laceribractea
+	Leaves membranous		(32)
32 (31)	Leaf blade suborbicular, deeply palmately 5-7-lobed; bract margin crenulate; calyx segments ca. 15 mm, entire.		15 T. wallichiana
+	Leaf blade orbicular-cordate or broadly ovate-cordate, unlobed or irregularly 2- or 3(-5)-lobed; bract margin lobulate with linear- lanceolate lobes; calyx segments ca. 10 mm, entire or serrate.		16 T. fissibracteata