1	Fruit 1-loculed, 1-seeded; evergreen (C. sect. Sempervirentes)		(2)
+	Fruit 3-loculed, 3-6-seeded; deciduous or evergreen		(5)
2 (1)	Lenticels of young branchlets not obvious; floral disk thin, cupuliform; stamens inserted on margin of disk; fruit small, 6.5-10 mm wide, globose		(3)
+	Lenticels of young branchlets obvious; floral disk carnose, shallowly discoid or slightly pillow-form; stamens inserted below disk; fruit large, 8-12 mm wide, widely elliptic, rarely globose		(4)
3 (2)	Leaves narrowly rectangular-elliptic, narrowly ovate-elliptic to elliptic-oblanceolate; secondary veins 5-7 pairs; valves without transverse rugae.		22 C. hindsii
+	Leaves ovate or widely elliptic; secondary veins 7-10 pairs; valves with transverse rugae.		23 C. tonkinensis
4 (2)	Young branchlets, leaves, and valves puce when dry; leaf blade papery to thinly leathery; valves rugose and curly when fruit ripe.		24 C. monospermus
+	Young branchlets, leaves, and valves yellowish green when dry; leaf blade thickly leathery; valves not rugose and curly when fruit ripe.		25 C. virens
5 (1)	Inflorescences generally terminal, occasionally axillary in upper part of branches (C. sect. Celastrus)		(6)
+	Inflorescences axillary, or both axillary and terminal (C. sect. Axillares)		(7)
6 (5)	Branchlets not obviously angled; leaf blade small, 5-10 × 2.5-5 cm, narrowly elongate; sepals imbricate; disk cupulate.		1 C. paniculatus
+	Branchlets generally 4-6-angled; leaf blade large, 7-18 × 5-14 cm, relatively broad; sepals valvate; disk disciform.		2 C. angulatus
7 (5)	Inflorescences usually axillary; seeds generally crescentiform or curved-semiorbicular; if seeds elliptic, bud scales thornlike (C. flagellaris)		(8)
+	Inflorescences both axillary and terminal; seeds usually elliptic		(15)
8 (7)	Outer scales of buds thornlike, thorn 1.5-2.5 mm; seeds elliptic.		14 C. flagellaris
+	Bud scales not thornlike; seeds crescentiform or curved-semiorbicular		(9)
9 (8)	Petiole short, less than 9 mm		(10)
+	Petiole long, more than 10 mm, longest up to 30 mm		(11)
10 (9)	Leaf blade widely obovate or rarely orbicular, 1.5-4 cm; petiole 1-5 mm; peduncle slender, 4-6.5 mm; fruit 6-7 mm wide.		15 C. cuneatus
+	Leaf blade oblanceolate, rarely widely oblanceolate, 6.5-12.5 cm; petiole 4-9 mm; peduncle subsessile, only ca. 2 mm; fruit 7.5-8.5 mm wide.		16 C. oblanceifolius
11 (9)	Fruit small, 4-5 mm wide; seeds small, ca. 2.5 mm.		17 C. homaliifolius
+	Fruit large, 6.5-10 mm wide; seeds large, 3-5 mm		(12)
12 (11)	Cymes 3-flowered; peduncle short, 2-5 mm; pedicels jointed distally.		18 C. aculeatus
+	Cymes 3-14-flowered; peduncle long, 5-20 mm; pedicels jointed below middle or near base		(13)
13 (12)	Leaf blade obovate or obovate-elliptic; cymes 7-14-flowered; young branchlets, peduncles, and pedicels densely brown hirsute.		19 C. hirsutus
+	Leaves oblong or elliptic; cymes 3-7-flowered; young branchlets, peduncles, and pedicels with very short brown or yellowish white stiff hairs		(14)
14 (13)	Young branchlets, peduncles, and pedicels with dense and very short brown stiff hairs; leaf blade widely elliptic to orbicular; secondary veins in 3 or 4 pairs.		20 C. kusanoi
+	Young branchlets, peduncles, and pedicels with very short yellowish white stiff hairs; leaf blade rectangular-elliptic, rarely rectangular-obovate; secondary veins in 5-7 pairs.		21 C. stylosus
15 (7)	Leaf blade abaxially pallid		(16)
+	Leaf blade same color on both surfaces		(19)
16 (15)	Leaf blade narrowly lanceolate.		3 C. franchetianus
+	Leaf blade broad, elliptic to broadly lanceolate or obovate-lanceolate		(17)
17 (16)	Petiole short, 8-12 mm; seeds elliptic.		4 C. glaucophyllus
+	Petiole long, 12-20 mm; seeds convex or slightly crescentiform		(18)
18 (17)	Terminal inflorescence long, 7-10 cm; leaf blade small, ovate or rectangular-elliptic, 6-9.5 × 2.5-5.5 cm, base widely cuneate; fruit stalk long, 10-25 mm.		5 C. hypoleucus
+	Terminal inflorescence short, 3-7 cm; leaf blade large, widely ovate, widely ovate-elliptic or orbicular, 6-13.5 × 3.5-9.5 cm, base widely rounded; fruit stalk short, 5-10 mm.		6 C. hypoleucoides
19 (15)	Veinlets obviously prominent and cancellate netted; leaf blade abaxially pubescent along veins.		7 C. rugosus
+	Veinlets not cancellate netted; leaf blade glabrous, or sometimes sparsely with short hair along veins		(20)
20 (19)	Terminal inflorescences long, 6-18 cm; valves adaxially maculate, macula small, brown.		8 C. vaniotii
+	Terminal inflorescence short, generally 1-6 cm (C. hookeri: sometimes up to 9 cm); valves without macula		(21)
21 (20)	Winter buds large, 5-12 mm; fruit large, 10-12 mm wide; filament sometimes with papillate hairs.		9 C. gemmatus
+	Winter buds small, 1-3 mm; fruit small, 5.5-10 mm wide; filament smooth		(22)
22 (21)	Petiole 2-8 mm; leaf blade up to 9 cm, elliptic		(23)
+	Petiole usually more than 10 mm, longest up to 20 mm; leaf blade up to 13 cm, oblong, ovate, or nearly rounded		(24)
23 (22)	Leaf blade glabrous; pedicels jointed above middle.		10 C. punctatus
+	Leaf blade slightly pubescent along veins abaxially; pedicels jointed at or below middle.		11 C. rosthornianus
24 (22)	Terminal inflorescence long, 3-9 cm; pedicels jointed at or above middle; capsule 6-7 mm wide.		12 C. hookeri
+	Terminal inflorescence short, 1-3 cm; pedicels jointed below middle or near base; capsule 8-10 mm wide.		13 C. orbiculatus