448 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Leaflets linear to nari'owly oblong; calyx lobes equaling or 

 exceeding the tube. 

 Calyx appressed-sericeous ; leaves slightly pubescent when 



young 57. P. glabrescens. 



Calyx loosely pilose; leaves glabrous from the first. 

 Leaflets linear-oblong, slightly involute ; petals rose- 



purple 58i P. lasiostachya. 



Leaflets linear, strongly involute; petals pink or whit- 

 ish 59. P. involuta. 



DD. Leaves conspicuously pubescent. 

 Plants densely sericeous. 



Leaves 3-foliolate 60. P. eriophylla. 



Leaves 5 to 11-foliolate 61. P. greggii. 



Plants not densely sericeous. 

 Petals (except sometimes the banner) dark purple. 



Calyx lobes shorter than the tube 62. P. oaxacana. 



Calyx lobes equaling or longer than the tube. 



Bracts deciduous 83. P. emoryi. 



Bracts persistent. 



Leaflets narrowly oblong, 2 to 4 mm. long, pubescent on both 



sides 63. P. tsugoides. 



Leaflets broadly oblong, 4 to 7 mm. long, glabrous on the 

 upper surface. 

 Corolla rose-purple; calyx not conspicuously glandular. 



64. P. versicolor. 

 Corolla dark bluish purple ; calyx with conspicuous glands 



between the ribs 46. P. atrocyanea. 



Petals rose-colored to white. 



Spikes short, often subglobose, sessile at the ends of short leafy 



branches 65. P. sessilis. 



Spikes elongate, usually pedunculate at the ends of elongate 

 branches. 

 Leaflets villous-sericeous ; branches villous-canescent. 



Branches glandular-tuberculate ; petals usually without 



glands 66. P. megalostachys. 



Branches not conspicuously glandular; petals with a large 



gland near the apex 67. P. wislizeni. 



Leaflets and branches finely short-pubescent. 



Leaflets obtuse, sparsely pilose or glabrate above ; corolla 



rose 68. P. sanctae-crucis. 



Leaflets acute, finely short-pubescent above ; corolla nearly 



white 69. P. leucantha. 



BB. Calyx lobes short, ovate or lanceolate, usually much shorter than the 

 tube, rarely subulate-tipped. 

 Corolla yellow. 



Fruit exserted from the calyx. 



Stipular spines 3 to 9 mm. long ; only the terminal leaflet retuse ; 



banner about twice as broad as the other petals 70. P. benthami. 



Stipular spines 1 to 2 mm. long ; all leaflets retuse ; banner 3 to 4 



times as broad as the other petals 71. P. megacarpa. 



Fruit not exserted. 



Spikes elongate ; corolla fading to purple ; bracts caducous. 



72. P. acutifolia. 



