Group 3

1	Basal leaf blade surfaces with malpighiaceous trichomes.		61 Draba malpighiacea
+	Basal leaf blade surfaces with simple, 2-rayed, forked, stellate, or dendritic trichomes		(2)
2 (1)	Abaxial surface of leaf blades with some 7-15-rayed trichomes		(3)
+	Abaxial surface of leaf blades with 2-5 (or 6)-rayed trichomes		(11)
3 (2)	Petals yellow; stem and basal leaf trichomes crisped.		110 Draba streptobrachia (in part)
+	Petals white or creamy white; stem and basal leaf trichomes usually non-crisped		(4)
4 (3)	Margins of basal and cauline leaf blades entire		(5)
+	Margins of basal and, sometimes, cauline leaf blades usually dentate or denticulate, if entire, racemes not flexuous in fruit		(8)
5 (4)	Plants usually forming mats; rachises slightly flexuous		(6)
+	Plants not forming mats; rachises not flexuous		(7)
6 (5)	Fruits 6-15(-18) mm; adaxial surface of leaf blades with simple and long-stalked, 2-rayed trichomes.		57 Draba lonchocarpa (in part)
+	Fruits 3.5-9 mm; adaxial surface of leaf blades with short-stalked, 8-15-rayed trichomes.		68 Draba nivalis (in part)
7 (5)	Rachises pubescent; ovules 22-32 per ovary; sepals persistent (until fruiting); e California, w Nevada.		21 Draba californica (in part)
+	Rachises glabrous; ovules 12-16 per ovary; sepals caducous; Alaska, Alberta, w Montana, nw Wyoming.		86 Draba porsildii (in part)
8 (4)	Cauline leaves usually 0, rarely 1 (as a bract); basal leaf blades each with prominent midvein; sepals glabrous or, rarely, with simple trichomes subapically.		55 Draba lactea (in part)
+	Cauline leaves usually 2-25, rarely 1 (D. chamissonis); basal leaf blades each with obscure midvein; sepals with 2-5-rayed trichomes		(9)
9 (8)	Fruits 1.1-1.6(-2) mm wide; petals 2-3.5 mm; petiole margins not ciliate; proximalmost flowers bracteate.		24 Draba chamissonis
+	Fruits 2-3.5 mm wide; petals 3.5-5.5 mm; petiole margins ciliate; proximalmost flowers usually ebracteate (sometimes bracteate in D. glabella)		(10)
10 (9)	Abaxial surface of leaf blades with sessile, stellate trichomes; styles (0.2-)0.4-1 mm; stems proximally with 8-12-rayed trichomes.		6 Draba arabisans (in part)
+	Abaxial surface of leaf blades with short-stalked, stellate trichomes; styles 0.05-0.2(-0.5) mm; stems proximally with some simple trichomes.		38 Draba glabella (in part)
11 (2)	Stem and leaf trichomes sessile, 2 rays parallel to long axis of stem or midvein, some malpighiaceous.		104 Draba spectabilis (in part)
+	Stem and leaf trichomes stalked, rays not parallel to long axis of stem or midvein, not malpighiaceous		(12)
12 (11)	Caudex fleshy, simple; petiole of basal leaves (1-)4-15 cm; fruits 4-7(-9) mm wide.		41 Draba grandis
+	Caudex not fleshy, usually branched, rarely simple; petiole of basal leaves obsolete or 1-2 cm; fruits 1-4(-6) mm wide		(13)
13 (12)	Abaxial surface of leaf blades with either cruciform or pectinate trichomes		(14)
+	Abaxial surface of leaf blades with cruciform and 2-6-rayed trichomes		(15)
14 (13)	Plants pulvinate, caudex densely branched; abaxial surface of leaf blades with pectinate trichomes; ovules 8-16(-20) per ovary.		48 Draba incerta (in part)
+	Plants not pulvinate, caudex loosely branched; abaxial surface of leaf blades with cruciform trichomes; ovules 16-30 per ovary.		52 Draba juvenilis (in part)
15 (13)	Seeds 1.8-2.8 × 1.2-2 mm, wing 0.5-1 mm wide; fruits (3.5-)4-6 mm wide.		12 Draba asterophora (in part)
+	Seeds 0.7-1.4(-1.6) × 0.4-0.8(-1) mm, not winged; fruits 1-4(-5) mm wide		(16)
16 (15)	Styles (0.6-)0.8-3.6 mm; petals 4-8.5 mm; anthers usually oblong (ovate in D. murrayi)		(17)
+	Styles 0.01-0.6 mm; petals 1.8-4 mm; anthers ovate		(19)
17 (16)	Petals white; anthers ovate, 0.4-0.5 mm; fruits 1.5-2 mm wide; styles 0.6-1.5 mm.		66 Draba murrayi
+	Petals yellow; anthers oblong, 0.6-1 mm; fruits 2-5 mm wide; styles (0.8-)1-3.6 mm		(18)
18 (17)	Fruits plane; ovules 10-18 per ovary; basal leaf blades (2-) 4-10(-14) mm wide; cauline leaves (3-)5-9(-11); petals 4-6 mm.		1 Draba abajoensis
+	Fruits slightly twisted; ovules 24-36 per ovary; basal leaf blades 7-25(-33) mm wide; cauline leaves 1-3; petals (5-) 6-8.5 mm.		63 Draba mogollonica (in part)
19 (16)	Rachises usually glabrous, (rarely sparsely pubescent in D. stenoloba); fruits usually linear, elliptic, or linear-lanceolate, rarely lanceolate, 1-2(-2.5) mm wide; styles 0.01-0.15(-0.2) mm		(20)
+	Rachises pubescent; fruits lanceolate to oblong or ovoid, (1.8-) 2-4 mm wide; styles 0.1-0.6 mm		(22)
20 (19)	Sepals pubescent, trichomes simple and 2- or 3-rayed; abaxial surface of leaf blades with trichomes (2-)4(-6)-rayed.		78 Draba paucifructa (in part)
+	Sepals glabrous or sparsely pubescent, trichomes simple; abaxial surface of leaf blades with trichomes 2-4-rayed		(21)
21 (20)	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)
22 (19)	Petals yellow; fruits ovoid to ovoid-lanceolate, inflated (at least basally); ovules (4-)8-12 per ovary.		103 Draba sobolifera (in part)
+	Petals white or creamy white; fruits oblong, lanceolate, or lanceolate-elliptic, flattened; ovules 18-32 per ovary		(23)
23 (22)	Fruiting pedicels pubescent, trichomes 4-8-rayed; sepals persistent; petals 0.8-1 mm wide; e California, w Nevada.		21 Draba californica (in part)
+	Fruiting pedicels pubescent, trichomes simple and 2-4-rayed; sepals caducous; petals 1.7-2.5 mm wide; Canada, Greenland.		69 Draba norvegica (in part)