1	Adaxial calyx teeth 1.5-4 × as long as tube; legume usually prickly or ribbed (but unknown for some species); leaflet blades leathery, lateral veins obscure		(2)
+	Adaxial calyx teeth ± as long as to shorter than tube; legume surfaces without prickles or ribs; leaflet blades membranous, lateral veins conspicuous		(15)
2 (1)	Legume articles without conspicuous septa, with triangular and irregular prickles along margins; stipules apically connate.		1 H. tibeticum
+	Legume articles with conspicuous septa, without prickles or with linear and regular prickles along margins; stipules mostly apically distinct		(3)
3 (2)	Stems longer than 15 cm		(4)
+	Stems 4 cm or less		(8)
4 (3)	Corolla pale yellow.		29 H. dahuricum
+	Corolla purple or pinkish purple		(5)
5 (4)	Corolla wings ca. 2/5 as long as standard.		30 H. brachypterum
+	Corolla wings 1/2-3/4 as long as standard		(6)
6 (5)	Stems ascending, 15-20 cm tall; corolla 1.5-1.7 cm.		31 H. gmelinii
+	Stems erect to ascending at base, 30-90 cm tall; corolla 1-1.4 cm		(7)
7 (6)	Leaflet blades narrowly elliptic to lanceolate, 1-1.2 × 0.3-0.5 cm.		32 H. songaricum
+	Leaflet blades oblong-ovate, 3-3.5 × 0.6-0.7 cm.		33 H. shanense
8 (3)	Leaflet blades adaxially glabrous, subglabrous, or with scattered trichomes		(9)
+	Leaflet blades adaxially sparsely pilose, sparsely pubescent, or pubescent		(10)
9 (8)	Calyx teeth 2-3 × as long as tube; corolla wings 1/4-1/3 as long as standard; leaflets 4-9 mm.		34 H. petrovii
+	Calyx teeth 1.5-2 × as long as tube; corolla wings ca. 1/5 as long as standard; leaflets 12-16 mm.		35 H. setigerum
10 (8)	Leaves 13-24-foliolate.		36 H. kumaonense
+	Leaves 3-13-foliolate		(11)
11 (10)	Leaflet blades ovate or broadly ovate; legume tomentose or pubescent		(12)
+	Leaflet blades narrowly ovate-lanceolate, lanceolate-elliptic, ovate-oblong, narrowly elliptic, ovate, or ovate-elliptic; legume with dense hyaline scalelike trichomes (unknown for H. setosum)		(13)
12 (11)	Leaves 3-7-foliolate.		37 H. iliense
+	Leaves 7- or 9-foliolate.		38 H. splendens
13 (11)	Stems 1-2 cm; leaflet blades narrowly ovate-lanceolate to lanceolate-elliptic, 1.2-1.5 cm.		39 H. krylovii
+	Stems inconspicuous; leaflet blades ovate-oblong, narrowly elliptic, ovate, or ovate-elliptic, 0.6-0.9 cm		(14)
14 (13)	Corolla 1.2-1.4 cm; calyx 7-8 mm; plants 5-15 cm tall.		40 H. ferganense
+	Corolla 1.7-2 cm; calyx 8-10 mm; plants 15-20 cm tall.		41 H. setosum
15 (1)	Legume articles with a ca. 1 mm dentate margin.		2 H. dentatoalatum
+	Legume articles with a 0.5 mm or less dentate or entire margin (unknown for H. xizangense)		(16)
16 (15)	Legume articles pyramidal.		3 H. trigonomerum
+	Legume articles ovoid, globose, subglobose, ellipsoid, or rhomboid (unknown for H. xizangense)		(17)
17 (16)	Corolla yellow		(18)
+	Corolla pinkish purple to dark purple (red but apically dark purple in H. kirghisorum, unknown for H. longigynophorum)		(25)
18 (17)	Calyx teeth ± equal		(19)
+	Most abaxial calyx tooth 2-3 × as long as others		(22)
19 (18)	Leaves 9-15-foliolate; leaflet blades 1-2 cm wide		(20)
+	Leaves 13-33-foliolate; leaflet blades 0.4-0.7 cm wide		(21)
20 (19)	Racemes distinctly longer than leaves; legume article margins entire.		6 H. flavescens
+	Racemes ± as long as leaves; legume article margins dentate.		7 H. semenovii
21 (19)	Leaves 13-27-foliolate; leaflet blades long ovate to ovate-lanceolate, abaxially dark brownish and adaxially greenish.		4 H. limitaneum
+	Leaves 27-33-foliolate; leaflet blades ovate-oblong, abaxially and adaxially greenish.		5 H. thiochroum
22 (18)	Bracts marcescent, 1/4-2/3 as long as pedicels.		8 H. polybotrys
+	Bracts caducous, ca. 2/3 as long as to longer than pedicels		(23)
23 (22)	Legume article wings inconspicuous, entire; calyx densely pubescent.		9 H. citrinum
+	Legume article wings conspicuous, dentate; calyx sparsely pubescent		(24)
24 (23)	Adaxial most calyx tooth 0.7-1.5 × as long as tube, others less than 1/2 as long as tube; pedicel 5-6 mm.		10 H. ussuriense
+	Adaxial most calyx tooth 1.5-2 × as long as tube, others 1/2 to as long as tube; pedicel 3-4 mm.		11 H. taipeicum
25 (17)	Auricle of corolla wing less than 1/2 as long of claw; calyx teeth subulate, apex long cuspidate.		18 H. falconeri
+	Auricle of corolla wing as long as claw; calyx teeth triangular, triangular-subulate, or lanceolate, apex not long cuspidate		(26)
26 (25)	Leaflet blades adaxially pubescent, sericeous, or tomentose		(27)
+	Leaflet blades adaxially glabrous		(29)
27 (26)	Corolla wings equal to or longer than keel; calyx with adaxial 2 teeth connate.		19 H. campylocarpon
+	Corolla wings shorter than keel; calyx teeth not connate		(28)
28 (27)	Leaflet blades narrowly ovate to ovate, 20-24 × 7-9 mm; bracteoles shorter, 0.4-0.7 mm; lateral veins conspicuous.		28 H. taoriparium
+	Leaflet blades broadly ovate to suborbicular, 6-10 × 5-10 mm; bracteoles longer, 3.5-5 mm; lateral veins sometimes inconspicuous.		20 H. pseudastragalus
29 (26)	Corolla keel shorter than standard and wing, wings not curved upward at apex; legume often inconspicuously constricted between articles at abaxial suture.		12 H. inundatum
+	Corolla keel longer than standard or wing, wings curved upward at apex; legume conspicuously constricted between articles		(30)
30 (29)	Bracts obovate to obtuse, apex usually dentate; rhizomes often with tubercle; leaflet blades obovate, elliptic, or suborbicular.		21 H. algidum
+	Bracts ovate or obovate, apex acute or acuminate; rhizomes without tubercle; leaflet blades ovate, elliptic, or oblong		(31)
31 (30)	Pedicel 1.5-2.5 cm.		25 H. jinchuanense
+	Pedicel 0.2-0.6 cm		(32)
32 (31)	Legume articles 1 or 2, rhomboid.		24 H. longigynophorum
+	Legume articles (1 or)2-5, ovate, obovate, or elliptic		(33)
33 (32)	Adaxial calyx teeth 1/5-1/3 as long as tube		(34)
+	Adaxial calyx teeth ca. 1/2 as long as to equal to tube		(35)
34 (33)	Bract marcescent; racemes densely flowered.		13 H. alpinum
+	Bract caducous; racemes laxly flowered.		14 H. laxiflorum
35 (33)	Legume articles acute at apex; stem and leaves sericeous		(36)
+	Legume articles obtuse at apex; stem and leaves tomentose		(37)
36 (35)	Corolla wings longer than standard; leaflet blades 2-4 cm; legume pubescent.		26 H. fistulosum
+	Corolla wings shorter than standard; leaflet blades 1-1.5 cm; legume glabrous.		15 H. nagarzense
37 (35)	Corolla 2.1-2.5 cm.		22 H. tanguticum
+	Corolla 1.2-2 cm		(38)
38 (37)	Leaflet blades 1.9-3 × 0.6-1.4 cm		(39)
+	Leaflet blades 1-1.6 × 0.5-0.9 cm		(40)
39 (38)	Corolla red, with dark purple at apex; bracts slightly longer than pedicel; plants 15-30 cm tall.		16 H. kirghisorum
+	Corolla purple, not dark purple at apex; bracts ca. 2 × as long as pedicel, subequal to calyx teeth; plants 30-60(-90) cm tall.		17 H. neglectum
40 (38)	Racemes dense; pedicel 2-3 mm; calyx teeth narrowly lanceolate; corolla standard long obovate, 1.2-1.4 cm, keel 1-2 mm longer than standard.		23 H. sikkimense
+	Racemes lax; pedicel 3-4 mm; calyx teeth triangular-lanceolate; corolla standard obovate, 1.4-1.5 cm, keel 2-3 mm longer than standard.		27 H. xizangense