358 BRASSICACEAE 



Pod about 2 mm. wide, obtuse. 25. A. Egglestonii. 



Leaves thiji, green; stem branched. 26. A. rccondita. 



Leaves more coarsely hairy, with branched hairs or merely ciliate on the margins. 

 Leaves densely hairy. 27. A. selulosa. 



Leaves sparingly hairy or merely ciliate. 



Plant green, not glaucous; pods 3 cm. long; seeds in one row but irregularly so. 

 Leaves firm, ciliate or somewhat hairy. 28. A. rugncarpa. 



Leaves thin, almost perfectly glabrous. 29. A. oxylobula. 



Plant glaucous or bluish-green; pods 4-5 cm. long; seeds in two rows. 



SO. A. spatifolia. 

 XI. Arcuat.\e. 

 Pedicels and calyx long-ciliate. 31. A. perelegans. 



Pedicels glabrous or merely stellate. 



Calyx more or less stellate; petals 8 mm. long. 



Stem 3-6 dm. high; basal leaves 2-4 cm. long, entire. 33. A. Bourgovii. 



Stem 5-10 dm. high; basal leaves 5-10 cm. long, denticulate. 



34. A. Selbyi. 

 Calyx glabrous or nearly so. 



Leaves decidedly stellate; plants biennial. 



Pods straight or slightly curved upwards, ascending-spreading. 



32. A. brachycarpa. 

 Pods more or less arcuate and somewhat drooping. 



Pods 8-10 cm. long; petals 8-10 mm. long. 35. A. Stokesiae. 



Pods 4-6 cm. long; petals 5-8 mm. long. 

 Stem-leaves narrowly lajiceolate. 



Petals 8-10 mm. long, purple. 36. A. divaricarpa. 



Petals about 5 mm. long, wliite or pinkish. 37. A. densicaulis . 

 Stem-leaves ovate, or oblong. 38. A. fruclicosa. 



Leaves coarsely stellate-hirsute; plants perennial. 



Stem-leaves conspicuously sagittate at the base; sepals Unear-oblong. 



39. A. gracilenta. 

 Stem-leaves with inconspicuous auricles at the base; sepals broadly elliptic. 



Basal leaves sparingly hirsute; stem-leaves lanceolate, 1.5-3 cm. long. 



40. A. Fendleri. 

 Basal leaves densely hairy; stem-leaves oblong-lanceolate, 1-1.5 cm. long. 



27. A. setulosa. 

 XII. Retrofractae. 

 Stem-leaves decidedly sagittate at the base. 



Plants not densely cespitose; stem mostly soUtary (except in A. lignifera); biennials. 

 Pedicels of the fruit merely recurved. 



Leaves dentate. 41. A. consanguinea. 



Leaves entire. 



Seeds in one row; pod 3-4 cm. long; sepals stellate. 42. A. lignifera. 

 Seeds in two rows; pod less than 3 cm. long; sepals glabrous. 



43. A. brevisiliqua . 

 Pedicels in fruit strictly reflexed. 



Seeds in one row; pods 4-7 cm. long. 



Petals 6—10 mm. long; stem-leaves usually ample. 



Racemes not secund. 44. A. rhodantha. 



Racemes secund. 45. A. retrofracta. 



Petals about 5 mm. long; stem-leaves narrow, serrulate. 



46. A. lignipes. 

 Seeds in two rows; pod 1.5-3.5 cm. long. 47. A. caduca. 



Plant densely cespitose; basal leaves Unear-oblanceolate; perennials. 



48. A. canescens. 

 Stem-leaves scarcely sagittate at the base. 



Plant 3 dm. high or more, sparingly stellate; flowers numerous. 49. A. eiilis. 



Plant 1-2 dm. high, densely stellate below; flowers few. 50. A. pendulocarpa. 



1. A. lyrata L. Stem 1-3 dm. high, glabrous or sparingly pubescent below; 

 basal leaves 2-5 cm. long, sparingly hairy or glabrate; stem-leaves spatulate to 

 linear, 1-2.5 cm. long; petals 6-8 mm. long, white; fruiting pedicels ascending 

 or spreading, 6-8 mm. long; pods 1.5-3 cm. long. Rocky places: Conn. — S.C. 

 — Mo. — ^Sask. Boreal. i*p-Jl. 



2. A. ambigua DC. Stem branched at the base, 2-4 dm. high, glabrous 

 or nearly so; basal leaves glabrous or sparingly pubescent, 2-4 cm. long; stem- 

 leaves spatulate, entire or toothed; petals white, about 6 mm. long; pedicels in 

 fruit ascending, about 1 cm. long; pods erect or nearly so, 2-3 cm. long. Wet 

 rocky places: Alta. — Mont. — Wash. — Alaska; e Asia. Subalp. My-Au. 



3. A. Nuttallii B. L. Robins. Biennial or perennial, more or less cespitose; 

 stems 1-3 dm. high, sparingly hirsute below; basal leaves short-petioled, spatu- 

 late, 1-3 cm. long; stem-leaves oblanceolate, sessile; petals white, 4-6 mm. long; 

 pedicels 8-15 mm. long; pods 1-3 cm. long. A. spalhulaia Nutt., not DC. 

 Mountains: Mont. — 'Utah — Wash. Submont. — Mont. My-Jl. 



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