472 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



29. Ridges of the pod not hard or sharp-edged, the pods 1-celled, 8 mm' 



long or longer, stipitate, pendulous, strigose, deeply grooved on 

 each side of the very prominent ventral suture; seeds several; 



racemes dense, many-flowered 7. A. haydenianus. 



28. Walls of the pods not transversely ridged and furrowed, but sometimes 

 conspicuously cross-veined (30). 



30. Pods more or less completely 2-celled, the lower suture introverted 



to form a septum extending at least halfway across the cavity (31). 

 31. Length of the pods less than 3 times the greatest diameter (32). 

 32. Pods incompletely 2-celled, elliptic, nearly sessile, 10 to 15 mm. 

 long, about 6 mm. wide; flowering stems from slender creeping 

 rootstocks; leaflets elliptic to obovate, less than 10 mm. long, 

 mostly refuse at apex; racemes few-flowered; calyx teeth subu- 

 late, about equaling the tube; corolla about 7 mm. long. 



49. A. COBRENSIS. 

 32. Pods completely 2-celled, ovoid (33). 



33. Herbage copiously strigose to white-sericeous; pods often 



mottled, 15 to 20 mm. long; corolla 9 to 15 mm. long (34). 



. 34. Pods glabrous or not densely strigose; plant green, strigose 



or somewhat canescent 57. A. fremontii. 



34. Pods rather densely strigose or sericeous; plant whitish 



sericeous or tomentose 58. A. coulteri. 



33. Herbage sparsely strigose or glabrate (the leaflets rarely seri- 

 ceous beneath) ; pods not or only exceptionally mottled (35) . 



35. Calyx 5 to 9 mm. long; pods 20 to 25 mm. long. 



59. A. diphysus. 

 35. Calyx 4 to 6 mm. long; pods 9 to 15 mm. long. 



60. A. MACDOUGALI. 



31. Length of the pods 3 or more times the greatest diameter (36). 

 36. Pods 3 to 4 times as long as their greatest diameter (37). 



37. Leaflets linear, 6 or more times as long as wide; pods con- 

 spicuously veiny, their greatest diameter above the middle. 



48. A. brandegei. 

 37. Leaflets broader than linear, less than 6 times as long as wide; 

 pods not conspicuously veiny, their greatest diameter at or 

 below the middle (38) . 

 38. Pods long-stipitate, glabrous, the walls coriaceous. 



53. A. EREMITICUS. 

 38. Pods sessile or nearly so (39). 



39. Leaflets and pods whitish sericeous; calyx 5 mm. long; 

 pods lanceolate in outline; plant annual. 



61. A. AGNINUS. 



39. Leaflets and pods strigose or glabrate; calyx 7 to 10 mm. 



long (40). 



40. Inflorescence rather short and compact; corolla whitish 



or purplish pink; pods erect or ascending, usually 



mottled 55. J A. wilsoni. 



40. Inflorescence elongate, very open; corolla purple; pods 



spreading, not mottled 56. A. mokiacensis. 



36. Pods 4 or more times as long as their greatest diameter (41). 

 41. Stipe of the pod conspicuous, usually equaling or surpassing 

 the calyx; leaflets glabrous above or nearly so (42). 

 42. Pedicels not or seldom recurved; pods erect or ascending, 

 glabrous, the walls coriaceous; corolla about 15 mm. long, 



purple or whitish 53. A. eremitic us. 



42. Pedicels recurved, at least in fruit; pods pendulous, the walls 

 thin ; corolla 6 to 8 mm. long, whitish (43) . 

 43. Pods strigose, the stipe often surpassing the calyx. 



50. A. RUSBYI. 

 43. Pods glabrous, the stipe usually shorter than the calyx. 



51. A. EGGLESTONII. 



41. Stipe of the pod none or much shorter than the calyx (44). 

 44. Pods very strongly arcuate, sometimes forming almost a 

 complete circle, 30 to 50 mm. long 62. A. layneae. 



