Group 1

1	Cauline leaves 0		(2)
+	Cauline leaves 1-54(-76)		(7)
2 (1)	Petals deeply 2-fid; rachises of fruiting racemes flexuous.		117 Draba verna
+	Petals usually obtuse, rarely emarginate; rachises of fruiting racemes usually straight, if flexuous then petals yellow		(3)
3 (2)	Petals white; late-season flowers apetalous; fruit valves usually with antrorse, simple trichomes, rarely glabrous		(4)
+	Petals yellow; late-season flowers with petals; fruit valves usually glabrous, rarely puberulent		(5)
4 (3)	Racemes 10-50(-70)-flowered, elongated in fruit, rachises densely pubescent; fruiting pedicels densely pubescent.		31 Draba cuneifolia (in part)
+	Racemes (3-)5-12(-16)-flowered, subumbellate in fruit, rachises usually glabrous, rarely sparsely pubescent; fruiting pedicels glabrous or sparsely pubescent.		92 Draba reptans (in part)
5 (3)	Abaxial surface of leaf blades glabrous or sparsely pubescent, trichomes simple and 2-rayed; stems usually glabrous, rarely pubescent proximally, trichomes simple.		29 Draba crassifolia (in part)
+	Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; stems pubescent, trichomes 2-4-rayed (sometimes simple)		(6)
6 (5)	Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12(-15) mm.		2 Draba albertina (in part)
+	Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-)10-17(-20) mm.		108 Draba stenoloba (in part)
7 (1)	Styles (0.8-)1-3.5 mm		(8)
+	Styles 0.01-0.6 (-0.8) mm		(12)
8 (7)	Adaxial surface of basal leaf blade pubescent with simple, subsetiform trichomes, rarely mixed with 2-rayed ones; fruit valves sparsely puberulent, trichomes simple.		15 Draba bifurcata (in part)
+	Adaxial surface of basal leaf blade pubescent with at least some 2-4-rayed trichomes; fruit valves usually pubescent, rarely glabrous, trichomes 2-4-rayed		(9)
9 (8)	Petals linear, 0.2-0.5 mm wide; s California.		26 Draba corrugata (in part)
+	Petals oblanceolate to spatulate, 1-3.5 mm wide; se Arizona, Colorado, New Mexico, Utah		(10)
10 (9)	Fruits plane, valves pubescent, trichomes 2-4-rayed; petals 3-5 × 1-1.5 mm, often fading whitish; Utah.		94 Draba santaquinensis (in part)
+	Fruits slightly to strongly twisted, valves glabrous, pubescent, or puberulent, trichomes simple and 2(-4)-rayed; petals 5-8.5 × 1.5-3.5 mm, not fading whitish; Arizona, Colorado, New Mexico		(11)
11 (10)	Cauline leaves (8-)12-31(-43); rachises pubescent; fruiting pedicels 4-10(-13) mm.		44 Draba helleriana (in part)
+	Cauline leaves 1-3; rachises often glabrous or, rarely, sparsely pubescent; fruiting pedicels (6-)9-18(-22) mm.		63 Draba mogollonica (in part)
12 (7)	Racemes bracteate basally; fruiting pedicels erect to ascending (subappressed to rachises); cauline leaves (15-)22-54(-76), densely overlapping proximally.		47 Draba incana
+	Racemes ebracteate; fruiting pedicels horizontal to divaricate-ascending (not appressed to rachises); cauline leaves 1-15(-25), seldom overlapping		(13)
13 (12)	Rachises glabrous		(14)
+	Rachises pubescent		(18)
14 (13)	Petals white or, rarely, absent; basal leaves not rosulate; racemes subumbellate in fruit.		92 Draba reptans (in part)
+	Petals yellow; basal leaves rosulate; racemes elongated in fruit		(15)
15 (14)	Cauline leaves 4-12(-15); fruiting pedicels 7-28(-35) mm, (1.5-)2-7 times longer than fruit.		67 Draba nemorosa
+	Cauline leaves 1-3(-5); fruiting pedicels (1-)3-14(-19) mm, subequaling or shorter than fruit		(16)
16 (15)	Abaxial surface of leaf blades glabrous or sparsely pubescent, trichomes simple and 2-rayed; stems usually glabrous, or, rarely, sparsely pubescent proximally, trichomes simple.		29 Draba crassifolia (in part)
+	Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; stems pubescent basally, trichomes 2-4-rayed (sometimes simple)		(17)
17 (16)	Stems proximally with simple and 2-rayed trichomes; adaxial surface of leaf blades with simple and 2-rayed trichomes; anthers 0.15-0.25 mm; fruits (4-)6-12(-15) mm.		2 Draba albertina (in part)
+	Stems proximally with 2-4-rayed trichomes; adaxial surface of leaf blades with 2-4-rayed trichomes; anthers 0.25-0.4 mm; fruits (8-)10-17(-20) mm.		108 Draba stenoloba (in part)
18 (13)	Leaf blade surfaces with cruciform trichomes		(19)
+	Leaf blade surfaces with simple and 2-7-rayed trichomes		(20)
19 (18)	Fruit valves pubescent; ovules 4-6(-8) per ovary.		5 Draba aprica
+	Fruit valves glabrous; ovules 8-16(-20) per ovary.		17 Draba brachycarpa
20 (18)	Fruits obovate to obovate-oblong.		85 Draba platycarpa
+	Fruits elliptic, oblong, linear, lanceolate, or, rarely, ovate		(21)
21 (20)	Late-season flowers apetalous; basal leaves not rosulate		(22)
+	Late-season flowers with petals; basal leaves rosulate		(23)
22 (21)	Racemes 10-50(-70)-flowered, elongated in fruit, rachises denselypubescent; fruiting pedicels densely pubescent.		31 Draba cuneifolia (in part)
+	Racemes (3-)5-12(-16)-flowered, subumbellate in fruit, rachises glabrous or, rarely, sparsely pubescent; fruiting pedicels glabrous or sparsely pubescent.		92 Draba reptans (in part)
23 (21)	Abaxial surface of leaf blades pubescent, trichomes 3-6-rayed; petals white.		87 Draba praealta (in part)
+	Abaxial surface of leaf blades pubescent, trichomes 2-4-rayed; petals yellow (sometimes fading white)		(24)
24 (23)	Styles 0.2-0.6(-0.8) mm; fruits 2-3.5 mm wide, valves pubescent, trichomes simple and 2-rayed.		18 Draba brachystylis (in part)
+	Styles 0.01-0.15 mm; fruits 1.3-2.3 mm wide, valves glabrous or pubescent, trichomes simple		(25)
25 (24)	Cauline leaves 3-10(-17); racemes (15-)20-51(-62)-flowered; fruits lanceolate, 6-9(-11) mm; Arizona, Colorado, New Mexico, Utah.		91 Draba rectifructa
+	Cauline leaves 1 or 2(-4); racemes (2-)4-10(-15)-flowered; fruits usually linear, rarely linear-elliptic, (8-)10-17(-20) mm; Alaska, Alberta, British Columbia, Washington, Yukon.		108 Draba stenoloba (in part)