1	Panicle usually similar to spike or capitulum; stem absent or solitary, stout, with dense leaves and large bracts, nodes inconspicuous.		(2)
+	Panicle terminal, without leaves or with bracts, not spicate or headlike; nodes usually inflated, stem rarely absent.		(10)
2 (1)	Stem stout, simple, with leaves and large bracts; panicle not similar to spike or capitulum; stamens longer than perianth.		(3)
+	Stem absent; panicle, similar to spike or capitulum; stamens subequal to perianth.		(4)
3 (2)	Plant 1-2 m tall; stem leaves ovate to orbicular; fruit broadly ovoid.		37 R. nobile
+	Plant short, 0.4-0.8 m tall; stem leaves ovate to narrowly ovate; fruit rhomboid-ellipsoid.		38 R. alexandrae
4 (2)	Plant very short, less than 10 cm; panicle similar to capitulum; fruit broadly ovoid, slightly constricted at both sides.		36 R. globulosum
+	Plant short, 10-30 cm; panicle similar to spike; fruit ellipsoid or ovoid.		(5)
5 (4)	Panicle deliquescently branched (with side branches).		(6)
+	Panicle not deliquescently branched (without side branches).		(7)
6 (5)	Leaves ovate or nearly rhomboid, glabrous, rarely hairy abaxially; panicles 2-4-branched; tepals broadly ovate, ca. 1.5 × 1.3 mm.		33 R. przewalskyi
+	Leaves ovate, long hairy abaxially; panicles straight, 1-3-branched from lower part; tepals narrowly elliptic, 2-2.5 × 0.8-1.2 mm.		34 R. rhizostachyum
7 (5)	Leaves rhombic, abaxially hairy; perianth purple-red.		32 R. rhomboideum
+	Leaves ovate or triangular-ovate, abaxially glabrous or hairy; perianth green or yellow-white.		(8)
8 (7)	Leaves broadly ovate or ovate-elliptic, both surfaces hairy, apex obtuse; fruit ellipsoid; perianth green.		30 R. spiciforme
+	Leaves ovate or triangular-ovate, glabrous or hairy abaxially, apex obtuse to acute; fruit ovoid or broadly ovoid; perianth yellow-white.		(9)
9 (8)	Leaves ovate, glabrous; panicle 2-4(or 5)-branched from base; fruit ovoid, 7-8 × 5-6 mm, wings 1-1.5 mm wide.		31 R. moorcroftianum
+	Leaves triangular-ovate, pubescent abaxially; panicle much branched from base; fruit broadly ovoid, 7.5-8.5 × 7-8 mm, wings ca. 2.5 mm wide.		35 R. reticulatum
10 (1)	Stem without leaves; leaves leathery or nearly so.		(11)
+	Stem leafy; leaf blade not leathery or papery.		(20)
11 (10)	Leaves papery, orbicular to cordate-orbicular; inflorescence 3-branched; joint of pedicel at upper part.		29 R. tataricum
+	Leaves leathery or nearly so, elliptic or ovate to orbicular; inflorescence 1(or 2)-branched; joint of pedicel beneath middle.		(12)
12 (11)	Stem absent; inflorescence usually 2-branched.		(13)
+	Stem with conspicuous nodes; inflorescence 1(or 2)-branched.		(15)
13 (12)	Leaves papery, longer than wide, ovate to narrowly ovate, palmate-pinnately veined; inflorescences caespitose from base.		26 R. uninerve
+	Leaves leathery, ca. as long as wide, reniform-orbicular to orbicular, conspicuously palmately veined; inflorescence solitary from base.		(14)
14 (13)	Leaves reniform-orbicular to orbicular, 6-14 × 8-16 cm; fruit shorter than wide, reniform-orbicular, 10-12 × 12-14 mm.		27 R. nanum
+	Leaves cordate to cordate-orbicular, 12-20 × 13-21 cm; fruit ca. as long as wide, ovoid, 8-10 mm.		28 R. tibeticum
15 (12)	Plant tall, 20(-30)-70 cm; leaves (5-)8-20 cm, abaxially glabrous or hairy.		(16)
+	Plant shorter, 10-30 cm; leaves 2-10 cm, abaxially at least hairy.		(18)
16 (15)	Leaves narrowly ovate to broadly lanceolate, glabrous, ca. 2 × as long as wide; fruit ovoid-ellipsoid.		21 R. sublanceolatum
+	Leaves ovate or triangular ovate, abaxially hairy or glabrous, slightly longer than wide; fruit ellipsoid or orbicular.		(17)
17 (16)	Plant 50-70 cm; leaves glabrous; fruit elliptic, narrow.		20 R. racemiferum
+	Plant 20-35 cm; leaves hairy abaxially; fruit orbicular, broad.		22 R. inopinatum
18 (15)	Leaves 6-10 × 4-7 cm, triangular-cordate or triangular ovate, apex acuminate; inflorescence broad.		25 R. subacaule
+	Leaves 2-6 × 1-5 cm, elliptic, ovate-elliptic, or oblong-elliptic, apex obtuse; inflorescence narrow.		(19)
19 (18)	Fruit triangular to triangular-ovoid, 5-6 mm; basal leaves ovate-elliptic, 1.5-5 × 1-3 cm.		23 R. pumilum
+	Fruit cordate-orbicular, 8-9 mm in diam.; basal leaves oblong-elliptic or ovate-elliptic, 3-6 × 2.5-5 cm.		24 R. delavayi
20 (10)	Plant 0.4-0.8 m tall, stem leaves 1 or 2(or 3), cordate, reniform-cordate, or triangular-cordate, margin entire; inflorescence a lax panicle, 1- or 2-branched.		(21)
+	Plant 0.5-2 m tall; stem leaves many, triangular-ovate; inflorescence large, more than 2-branched.		(24)
21 (20)	Plant 50-80 cm tall; leaves 13-28 × 12-25 cm; inflorescence usually 2-branched.		(22)
+	Plant 30-55 cm tall; leaves less than 10 cm; inflorescence 1- or 2-branched.		(23)
22 (21)	Stem and petioles purple-red or green, without spots; leaves cordate to broadly cordate, longer than wide; inflorescence branched from middle.		16 R. acuminatum
+	Stem and petioles green, with dense purple spots; leaves reniform or broadly cordate, ca. as long as wide or shorter; inflorescence branched from upper part.		17 R. maculatum
23 (21)	Flower large, pedicel 4-7 mm, shortly hairy; tepals 3-4 mm; leaves reniform-cordate or broadly cordate; fruit more than 10 mm.		18 R. yunnanense
+	Flower small, pedicel 2-3 mm, glabrous; tepals ca. 1.5 mm; leaves ovate-cordate or triangular-cordate; fruit 7-8 mm.		19 R. kialense
24 (20)	Leaves lobed, parted to laciniate.		(25)
+	Leaves entire, with crispate or sinuate margin.		(28)
25 (24)	Leaves lobed, lobed part triangular.		(26)
+	Leaves parted, lobed part narrow, triangular-lanceolate, or linear.		(27)
26 (25)	Lobed parts of blade broadly triangular; flowers large, perianth white; fruiting branches divaricate.		12 R. officinale
+	Lobed parts of blade narrowly triangular; flowers small, perianth purple-red; fruiting branches connivent.		13 R. palmatum
27 (25)	Lobed parts of blade narrowly lanceolate; perianth usually purple-red, tepals entire at margin.		14 R. tanguticum
+	Lobed parts of blade linear; perianth white, tepals slightly sinuolate at margin.		15 R. laciniatum
28 (24)	Leaves with sinuate margin.		(29)
+	Leaf margin sinuolate or slightly so.		(33)
29 (28)	Fruit 9-12 × 7-11 mm, wings broad, 4-5 mm.		5 R. wittrockii
+	Fruit less than 1 cm, with narrow or broad wings.		(30)
30 (29)	Leaves with 5-7 basal veins; leaf blade narrowly triangular to broadly ovate, not cordate.		(31)
+	Leaves with 5 basal veins; leaf blade cordate or broadly ovate.		(32)
31 (30)	Perianth white-green or yellow-white; rachis of panicle papilliferous.		1 R. rhabarbarum
+	Perianth purple-red; rachis of panicle densely pubescent.		2 R. australe
32 (30)	Leaf blade reniform-cordate or cordate, usually shorter than wide; perianth yellow-white.		3 R. webbianum
+	Leaf blade ovate-cordate or broadly ovate, usually longer than wide; perianth green.		4 R. hotaoense
33 (28)	Fruit 5.5-8 × 4.5-7 mm.		(34)
+	Fruit 9-12 × 7-11 mm.		(35)
34 (33)	Leaves ovate-cordate, apex not acuminate, margin sinuolate; tepals yellow-white.		6 R. altaicum
+	Leaves cordate-obovate to broadly ovate, apex acuminate, margin nearly entire; tepals purple at margin.		11 R. glabricaule
35 (33)	Tepals lanceolate; basal veins 5-9.		7 R. forrestii
+	Tepals broad, ovate or elliptic, not lanceolate; basal veins 5-7.		(36)
36 (35)	Stem, inflorescence, and branches densely white hispid; leaves broadly ovate or ovate.		8 R. likiangense
+	Stem, inflorescence, and branches glabrous or short hairy at nodes; leaves triangular-ovate or ovate-cordate.		(37)
37 (36)	Plant high 30-70 cm; leaves triangular to triangular-ovate; margin of tepals and anthers purple; fruit orbicular.		9 R. lhasaense
+	Plant ca. 1 m high; leaves ovate-cordate; perianth yellow-white; fruit ellipsoid to oblong-ellipsoid.		10 R. compactum