1	Corolla segments fimbriate at margin		(2)
+	Corolla segments not fimbriate		(3)
2 (1)	Ovules and seeds numerous; calyx tube less than 7 cm.		21 Trichosanthes
+	Ovules 12, seeds usually 6, each with 1 abortive seed attached to its side; calyx tube 7-10 cm.		20 Hodgsonia
3 (1)	Stamens 5, anther cells ovoid and straight		(4)
+	Stamens 3 or 1, anther cells horizontal when only 1 stamen, or rarely 5 but then anther cells conduplicate		(15)
4 (3)	Leaves palmately compound, rarely simple		(5)
+	Leaves simple		(9)
5 (4)	Plants woody, scandent; leaflets almost entire, with 2 glands at base; seeds with membranous wing at apex.		4 Neoalsomitra
+	Plants herbaceous, scandent; leaflets distinctly denticulate, eglandular at base; seeds without wing or rarely winged		(6)
6 (5)	Fruit indehiscent; seeds horizontal.		11 Thladiantha
+	Fruit 3-valved, dehiscent at apex or rarely not dehiscent but then smaller in size; seeds pendulous		(7)
7 (6)	Corolla segments more than 5 mm; fruit clavate-cylindric, obovoid, or globose, more than 6-seeded.		1 Hemsleya
+	Corolla segments less than 3 mm; fruit turbinate or globose, 1-3(-5)-seeded		(8)
8 (7)	Plants monoecious; fruit turbinate, 3-valved, dehiscent at apex.		2 Gomphogyne
+	Plants dioecious; fruit globose or campanulate, indehiscent or dehiscent along ventral suture.		3 Gynostemma
9 (4)	Flowers with corolla segments less than 10 mm; fruit dehiscent, operculate or 3-valved		(10)
+	Flowers with corolla segments ca. 2 cm, or if smaller then calyx longer than corolla; fruit baccate, indehiscent; seed not winged		(12)
10 (9)	Leaf blade entire; fruit 6-10 cm, truncate at apex, 3-valved; seeds surrounded by a membranous wing.		5 Zanonia
+	Leaf blade divided; fruit 1-3.5 cm, operculate; seed not winged or with membranous wing at apex		(11)
11 (10)	Plants monoecious; leaf blade cordate-hastate, eglandular at base; fruit dehiscent near middle; seeds not winged.		7 Actinostemma
+	Plants dioecious; leaf blade with 1 or 2 pairs of glands at base; fruit dehiscent near apex; seeds with membranous wing at apex.		6 Bolbostemma
12 (9)	Flowers with calyx longer than corolla; anthers reniform; fruit more than 10 cm.		8 Indofevillea
+	Flowers with corolla longer than calyx; anthers oblong; fruit less than 10 cm		(13)
13 (12)	Plants with black glandular scales.		9 Siraitia
+	Plants without glandular scales		(14)
14 (13)	Tendrils spiraling only above point of branching; anther cells straight.		11 Thladiantha
+	Tendrils spiraling also below point of branching; anther cells reniform-curved.		10 Sinobaijiania
15 (3)	Stamens united into a central column and pollen sac fusing into ring; leaf blade pedatipartite.		22 Cyclanthera
+	Stamens 3, or rarely 5 but then anther cells conduplicate; leaves not pedately compound		(16)
16 (15)	Flowers less than 10 mm in diam		(17)
+	Flowers more than 10 mm in diam		(24)
17 (16)	Plants dioecious or rarely flowers bisexual; fruit 3-valved from apex to base when mature; seeds 1-3, pendulous.		14 Schizopepon
+	Plants usually monoecious, rarely dioecious; fruit indehiscent; seeds often horizontal		(18)
18 (17)	Male flowers without pistillode; anther cells conduplicate; male and female flowers fasciculate in leaf axil.		29 Diplocyclos
+	Male flowers with globose or subulate pistillode; anther cells straight, curved or conduplicate		(19)
19 (18)	Anther cells incurved or reflexed.		33 Solena
+	Anther cells straight		(20)
20 (19)	Male flowers in sessile or subsessile fascicles; ovary hispid.		27 Mukia
+	Male flowers in pedunculate cymes, racemes, or umbels, or solitary; ovary glabrous or with fine hairs		(21)
21 (20)	Filaments as long as or longer than anthers, ca. 1 mm or more		(22)
+	Filaments shorter than anthers, 0.5-1 mm		(23)
22 (21)	Corolla yellow; filaments and staminodes glabrous except at very base; seeds scrobiculate.		28 Scopellaria
+	Corolla white or pale yellow; filaments and staminodes hairy above base; seeds smooth.		25 Zehneria
23 (21)	Anther connective not produced beyond thecae; stigmas glabrous, apically shortly 2-lobed; fruit black when ripe.		24 Melothria
+	Anther connective usually shortly produced beyond thecae; stigmas papillose, rounded; fruit white or red when ripe.		25 Zehneria
24 (16)	Anther cells straight; calyx tube narrowly funnelform.		17 Edgaria
+	Anther cells conduplicate		(25)
25 (24)	Tendrils absent.		13 Ecballium
+	Tendrils present		(26)
26 (25)	Corolla campanulate		(27)
+	Corolla rotate or rarely campanulate but then segments almost free		(28)
27 (26)	Leaf blade hirsute, eglandular at base; flowers yellow; fruit large.		35 Cucurbita
+	Leaf blade glabrous, with a few glands at base; flowers white; fruit ca. 5 cm.		30 Coccinia
28 (26)	Calyx tube in male flower elongate, tubular or funnelform		(29)
+	Calyx rotate		(32)
29 (28)	Flowers white; petiole apex 2-glandular.		31 Lagenaria
+	Flowers yellow; leaf blade eglandular at base		(30)
30 (29)	Corolla rotate; leaf blade less than 10 cm.		19 Gymnopetalum
+	Corolla campanulate; leaf blade over 10 cm		(31)
31 (30)	Leaf blade deeply lobed; seeds many, horizontal.		15 Biswarea
+	Leaf blade undivided; seeds few, pendulous.		16 Herpetospermum
32 (28)	Flowers with leaflike bract on pedicel; fruit usually muriculate, often 3-valved when mature.		12 Momordica
+	Flowers without bract on pedicel		(33)
33 (32)	Male inflorescence racemose or subumbellate		(34)
+	Flowers solitary or fascicled		(35)
34 (33)	Annual herb; fruit many seeded.		18 Luffa
+	Perennial climber; fruit 1-seeded; seed large.		23 Sechium
35 (33)	Calyx segments subleaflike, dentate, reflexed.		34 Benincasa
+	Calyx segments subulate, entire, not reflexed		(36)
36 (35)	Tendrils 2- or 3-fid; connective not produced.		32 Citrullus
+	Tendrils simple; connective produced beyond anther cells.		26 Cucumis