MUSTARD FAMILY 107 



V. MlCROPHTIxLAB. 



Stems more than 3 dm. high; 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. vride; stem-leaves oblong 

 or Unear, 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. PULCHRAE. 

 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. subpinnatiflda. 



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



VII. Sttffrtjtbscentes. 

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



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



VIII. Macotjnianae. 

 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. Pehennantes. 



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. Bgglestonii. 



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



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

 Leaves densely hairy. 27. A. setulosa. 



Leaves sparingly hairy or merely cUiate. 



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

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



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



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



30. A, spatifolia. 



XI. Abcuatab. 



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 sUghtly 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 Isjiceolate. 



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



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. 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 j4 FsTidlsri 

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



27. A. setulosa. 

 XII. Retrofhactae. 

 Stem-leaves decidedly sagittate at the base. 



Plants not densely cespitose; stem mostly solitary (except in A. Ugnifera); 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. Ugnifera. 

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



43. A. brevisiliqua. 



