1	"Inflorescence bracted throughout"	Tropidocarpum
1	"Inflorescence not bracted or only most proximal few flowers bracted"	2
2	"Plant scapose; cauline leaves 0"	3
2	"Plant not scapose; at least 1 cauline leaf present"	4
3	"Sepals 4--5 mm; petioles of previous year persistent"	Anelsonia
3	"Sepals 1.5--2.5 mm; petioles of previous year not persistent"	Draba
4	"Cauline leaves sessile, basally lobed to sagittate or clasping"	5
4	"Cauline leaves petioled, if sessile not basally lobed, sagittate, or clasping"	10
5	"All hairs tree-like"	Phoenicaulis
5	"Hairs various, not all tree-like"	6
6	"Hairs stalked, stellate (few simple)"	Arabis
6	"Hairs sessile, or if stalked then not stellate, or a mixture of > 1 type"	7
7	"Annual; stigma 2-lobed; petals dark-veined"	Caulanthus
7	"Biennial or perennial herb; stigma entire; petals not dark-veined"	8
8	"Petals +- white (pink or purple); young fruit appressed to rachis; plants glaucous distally"	Turritis
8	"Petals white, pink, lavender, or purple; young fruit variously oriented (appressed); plants not glaucous distally"	9
9	"Fruit flattened"	Boechera
9	"Fruit cylindric"	Transberingia
10	"All hairs sessile"	Erysimum
10	"Hairs simple or stalked and branched"	11
11	"Stigma 2-lobed"	12
11	"Stigma entire"	14
12	"Petals (6.5)8--10(12) mm"	Strigosella
12	"Petals (13)15--30 mm"	13
13	"Sepals 5--8 mm; hairs simple, stalked-forked"	Hesperis
13	"Sepals 10--15 mm; hairs many-branched"	Matthiola
14	"Cauline leaves 1--3-pinnately divided to dissected or comb-like"	15
14	"Cauline leaves entire, dentate, wavy (lobed)"	17
15	"Petals yellow; hairs many-branched"	Descurainia
15	"Petals white to +- purple; hairs generally a mixture of simple, 2-forked, many-branched"	16
16	"Perennial herb; leaves rigid"	Polyctenium
16	"Annual; leaves not rigid"	Sibara
17	"At least some leaves lobed or wavy"	Halimolobos
17	"All leaves entire or dentate"	18
18	"Petals yellow"	Draba
18	"Petals white, lavender, pink, or purple."	19
19	"Petals (4)5--20 mm; seeds winged"	20
19	"Petals 2--4(5) mm; seeds wingless"	21
20	"Fruit erect or ascending, generally < 2.5 mm wide; branched hairs on leaf surface generally 2--4-rayed"	Arabis
20	"Fruit generally reflexed, occasionally erect or ascending, >= 2 mm wide; branched hairs on leaf surface 2--12-rayed"	Boechera
21	"Fruit cylindric; seeds in 1 row"	Arabidopsis
21	"Fruit flat; seeds in 2 rows"	Draba