MUSTARD FAMILY 107 



V. MICROPHYLLAE. 



Stems more than 3 dm. liigh; basal leaves 3-10 cm. long. 11. A. oblanceolata . 



Stems usually less than 3 dm. high, from a branched caudex; basal leaves 1-2 cm. long. 

 Plant green; petals 7-8 mm. long; pods fully 2 mm. wide; stem-leaves ovate-lanceolate. 



12. A. oreophila. 

 Plant grayish; petals about 5 mm. long; pods 0.75-1.5 mm. wide; stem-leaves oblong 

 or linear, the lower oblanceolate. 

 Flowers few; pods more than 1 mm. wide; seeds somewhat 2-ranked; stem hirsute- 



ciliate below or glabrous. 13. A. microphylla. 



Flowers many; pods less than 1 mm. wide; seeds strictly in one row; stem finely 



stellate. 14. A. Crandallii. 



VI. PtJL,CHR.\E. 



Seeds distinctly in two rows; stem-leaves not auricled. 



Petals purple, 8-10 mm. long. 15. A. pulchra. 



Petals white, 10-12 mm. long. 16. A. formosa. 



Seeds in one row; stem-leaves more or less auricled; petals 5-8 mm. long. 



Leaves usually coarsely toothed; petals pink, 6-8 mm. long. 17. A. suhpinnalifida. 



Leaves entire; petals white, 5-6 mm. long. 18. A. MacDougalii. 



VII. SUFFRUTESCENTES. 



Stems suffrutescent at the base; pods reflexed. 19. A. suffrutescens. 



Stems not suffruticose ; pods spreading. 20. A. drepanoloba. 



VIII. Macoijnian.\^e. 

 Petals about 4 mm. long; pod 3-4 cm. long; basal leaves 1-2 cm. long. 



21. A. Macounii. 

 Petals about 8 mm. long; pod 4-6 cm. long; basal leaves 4-6 cm. long. 



22. A. arcoidea. 



IX. PERENN ANTES. 



One species. 23. A. perennans. 



X. Reconditae. 

 Leaves finely stellate. 



Leaves thick, canescent; stems simple. 



Pod about 1.5 mm. wide, acute. 24. A. Lemmonii. 



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



Leaves thm, green; stem branched. 26. A. recondita. 



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

 Leaves densely hairy. 27. A. setulosa. 



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. 



30. ^. spatifolia. 

 XI. Arctjatae. 

 Pedicels and calyx long-cfiiate. 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 decidedl.v 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 IgiUceolate. 



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



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

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



Leaves coarsely stellate-hirsute; plants perennial. 



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



39. ^. gracilenta. 

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



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



40. ^. 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 cospitose; stem mostly solitary (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 . 



