1	Leaves trinerved or triplinerved		(2)
+	Leaves pinninerved		(18)
2 (1)	Deciduous; fruits globose; short branchlets bearing inflorescence in leaf axil developing into normal branch		(3)
+	Evergreen; fruits ellipsoid; short branchlets bearing inflorescence usually not developing into normal branch		(5)
3 (2)	Leaves trifid, occasionally pentafid, trinerved, sometimes pentanerved.		24 L. obtusiloba
+	Leaves entire, trinerved or triplinerved		(4)
4 (3)	Umbels pedunculate; leaves trinerved or triplinerved.		23 L. neesiana
+	Umbels not pedunculate or peduncles less than 3 mm; leaves triplinerved.		22 L. rubronervia
5 (2)	Umbels solitary, inserted at upper leaf axil and lower bract axil on current year branchlets, peduncles slender, 1-2.5 cm, 10-20 × length of flower stipe; male flowers: stamens in 3rd whorl sometimes sterile, fasciated.		25 L. tienchuanensis
+	Inflorescences 1 to several, inserted on short branchlets, short branchlets usually not developing into normal branchlets, not pedunculate or shortly pedunculate and peduncles rather thick, usually less than 1 cm; male flowers: stamens in 3rd whorl fertile		(6)
6 (5)	Umbels distinctly pedunculate		(7)
+	Umbels not pedunculate or shortly pedunculate, peduncle less than 3 mm		(8)
7 (6)	Leaf blade elliptic to narrowly elliptic, caudate at apex, densely golden or white appressed sericeous abaxially, first and second pairs lateral veins not joined at apex and not inflexed.		26 L. chunii
+	Leaf blade ovate or ovate-oblong, apex acuminate, densely ferruginous pubescent on veins and then glabrous abaxially, first and second pairs lateral veins joined at apex and inflexed.		27 L. tonkinensis
8 (6)	Leaf blade usually 15 cm, rarely 10-12 cm; branchlets stout, current year branchlets usually more than 3 mm in diam		(9)
+	Leaf blade usually 6-11 cm (ca. 3.5 cm in L. fragrans, ca. 5 cm in L. supracostata); current year branchlets usually less than 3 mm in diam		(11)
9 (8)	Young branchlets and abaxial surface of leaf blade glabrous.		30 L. lungshengensis
+	Young branchlets and abaxial surface of leaf blade densely hairy		(10)
10 (9)	Young branchlets and abaxial surface of leaf blade ferruginous or brown pubescent; leaf blade elliptic or oblong, leathery; fruit stipes more than 5 mm.		28 L. prattii
+	Young branchlets and abaxial surface of leaf blade densely yellowish villous or tomentose; leaf blade broadly ovate, papery; fruit stipes not more than 5 mm.		29 L. guangxiensis
11 (8)	Young branchlets and abaxial surface of leaf blade very densely hairy, 2-year-old branchlets and leaves rather densely hairy, at least on furcate part of branchlet and veins of leaf blade abaxially		(12)
+	Young branchlets and abaxial surface of leaf blade laxly or densely pubescent, later glabrate or nearly glabrous		(14)
12 (11)	Leaf blade ovate, elliptic, or subrounded, acuminate or caudate-acuminate at apex, young branchlets and abaxial surface of leaf blade densely golden sericeous, brown pubescent, or glabrous.		38 L. aggregata
+	Leaf blade elliptic, oblong, or ovate, apex acuminate, young branchlets and abaxial surface of leaf blade densely gray-brown tomentose or yellowish brown tomentose		(13)
13 (12)	Buds, young branchlets, and abaxial surface of leaf blade densely gray-brown tomentose; 2-year-old branchlets gray-brown, slightly pubescent, rather smooth; leaf blade ovate or elliptic, old leaves at least tomentose abaxially on veins.		36 L. floribunda
+	Buds densely brown pubescent, young branchlets and abaxial surface of leaf blade, especially petiole, densely yellowish brown pubescent; 2-year-old branchlets yellowish brown, nearly glabrous, many lenticellate, rather scabrous; leaf blade oblong or obovate, later glabrate or only villous on midrib.		37 L. villipes
14 (11)	Fruits up to 1.4 cm; old leaves sometimes slightly black pubescent abaxially.		35 L. thomsonii
+	Fruits less than 1 cm; old leaves not slightly black pubescent abaxially		(15)
15 (14)	Leaf veins more convex adaxially than abaxially; filament, ovary, and style pubescent or glabrous		(16)
+	Leaf veins more convex abaxially than adaxially; filament, ovary, and style ± pubescent		(17)
16 (15)	Leaf blade caudate-acuminate at apex, ± repand on margin, first pair of lateral veins not elongate along margin up to apex; filament, ovary, and style pubescent.		31 L. supracostata
+	Leaf blade acuminate at apex, not repand on margin, first pair of lateral veins elongate along margin up to apex, sometimes very near margin; filament, ovary, and style glabrous.		32 L. fragrans
17 (15)	Branch surface with a thin layer of white exudations; leaf blade broadly ovate or broadly elliptic, sometimes ovate or elliptic, acute at apex.		33 L. limprichtii
+	Branch surface without white exudations; leaf blade narrowly ovate, oblong, or oblong-lanceolate, caudate-acuminate at apex.		34 L. pulcherrima
18 (1)	Umbels each one inserted at both sides under apical or axillary buds (i.e., short branch) or mixed bud (e.g., L. glauca), short branchlet developing into normal branchlet		(19)
+	Inflorescences clustered in leaf axil (i.e., many umbels inserted under apical bud of short branchlets in leaf axil), short branchlet usually 2-3 mm, developing or not developing into normal branchlet		(27)
19 (18)	Umbels distinctly pedunculate; hypocarpium developed, cup-shaped or shallowly cup-shaped, enclosed at or above base of fruit; fertile stamens with funnelform and long-stipitate glands		(20)
+	Umbels not pedunculate or peduncles shorter than pedicels and fruit stipes; hypocarpium not distinctly developed; fertile stamens with broadly reniform and stipitate glands		(22)
20 (19)	Leaves loose; fruits globose.		3 L. chienii
+	Leaves clustered at apex of branch; fruits ellipsoid		(21)
21 (20)	Hypocarpium cup-shaped; trees.		1 L. megaphylla
+	Hypocarpium shallowly cup-shaped; shrubs.		2 L. setchuenensis
22 (19)	Umbels pedunculate, peduncles shorter than stipes of flowers and fruits		(23)
+	Umbels not pedunculate or peduncles less than 3 mm		(25)
23 (22)	Leaf blade oblanceolate or obovate, red in autumn; young branchlets grayish white or grayish yellow, scabrous.		4 L. erythrocarpa
+	Leaf blade elliptic or broadly elliptic; young branchlets smooth, greenish gray or yellow-green		(24)
24 (23)	Young branchlets without lenticels, yellow-green; fruits less than 1 cm in diam., stipes without lenticels.		5 L. reflexa
+	Young branchlets with lenticels, greenish gray; fruits more than 1 cm in diam., stipes with lenticels.		6 L. praecox
25 (22)	Leaf blade obovate to oblanceolate, usually apex rounded; branchlets gray or grayish black.		9 L. kariensis
+	Leaf blade broadly ovate, elliptic, or elliptic-lanceolate, acuminate or acute at apex; branchlets yellow-green or white-yellow		(26)
26 (25)	Young branchlets white-yellow, brown pubescent; leaf blade broadly ovate or elliptic, occasionally nearly lanceolate; bud scales not keeled.		7 L. glauca
+	Young branchlets yellow-green, glabrous; leaf blade elliptic-lanceolate, apex rounded; bud scales keeled.		8 L. angustifolia
27 (18)	Umbels not pedunculate or shortly pedunculate, less than 3 mm, short branchlets bearing umbels not developed		(28)
+	Umbels and infructescences pedunculate, peduncles usually longer than or equaling length of pedicels and fruit stipes, short branchlets bearing umbels developing into normal branchlets		(30)
28 (27)	Young branchlets and abaxial surface of leaves densely yellow-brown villous, later slightly villous; leaf blade 6-11 × 3.5-6 cm.		19 L. nacusua
+	Young branchlets and abaxial surface of leaves laxly or densely yellow-white, gray-green, or yellow-brown pubescent, later glabrous or glabrate; leaf blade 3-9 × 1.5-3.5 cm		(29)
29 (28)	Perianth tube indistinct; leaf blade 4-9 cm.		20 L. communis
+	Perianth tube obconical; leaf blade 3-5 cm.		21 L. akoensis
30 (27)	Peduncles slender, more than ca. 4 × length of pedicels and ca. 7 × length of fruit stipes; fruits ovate.		10 L. gracilipes
+	Peduncles less than 4 × length of pedicels and 7 × length of fruit stipes; fruits globose		(31)
31 (30)	Leaf blade glabrous or laxly pubescent abaxially and on veins		(32)
+	Leaf blade densely pubescent abaxially		(35)
32 (31)	Leaf blade narrowly elliptic, usually more than 13 cm, reddish when dry.		11 L. longipedunculata
+	Leaf blade elliptic-lanceolate, lanceolate, or oblong, usually less than 13 cm, not reddish when dry		(33)
33 (32)	Lateral veins on both surfaces of leaf blade indistinct, leaf blade elliptic-lanceolate, papery.		12 L. kwangtungensis
+	Lateral veins on both surfaces of leaf blade distinct, leaf blade oblong, elliptic, or lanceolate, leathery, thinly leathery, or papery		(34)
34 (33)	Leaf blade leathery, oblong, grayish brown when dry; young branchlets robust, usually more than 3 mm thick.		13 L. robusta
+	Leaf blade papery or thinly leathery, elliptic to lanceolate, grayish brown or purple-brown when dry; young branchlets usually less than 3 mm thick.		14 L. metcalfiana
35 (31)	Leaf blade subleathery, densely brown pubescent or villous		(36)
+	Leaf blade papery, yellow-white pannose or gray-white or gray-yellow hirsute abaxially		(37)
36 (35)	Lateral veins 5-7 pairs, reticulate veins convex, honeycombed adaxially; young branchlets cylindric; leaf blade narrowly elliptic, 7.5-20.5 × 3-8 cm, shortly acuminate at apex.		15 L. foveolata
+	Lateral veins 9 or 10 pairs, reticulate veins not convex, not honeycombed adaxially; young branchlets angular; leaf blade usually ovate-oblong, 11-18 × 4-7 cm, cuneate at apex.		16 L. menghaiensis
37 (35)	Leaf blade yellow-white pannose abaxially; fruits 4-5 mm in diam..		17 L. motuoensis
+	Leaf blade gray-white or gray-yellow hirsute abaxially; fruits ca. 6 mm in diam..		18 L. latifolia