50 



NORTH AMERICAN FLORA 



[Volume 24 



Leaves glabrous. 



Leaflets oblong to oval. 

 Branches strigose. 

 Branches glabrous. 



Upper 4 calyx-lobes acute; branches ascending. 



Upper calyx-lobes lanceolate, as long as the tube. 

 Upper calyx -lobes ovate, shorter than the tube. 

 Upper 4 calyx -lobes obtuse, oblong, shorter than the tube; 

 branches spreading. 

 Leaflets linear. 



IV. Lasiostomae 

 Leaflets pubescent above; racemes lax; petals purplish. 



Leaflets pubescent on both sides. 



Leaflets glabrous beneath. 

 Leaflets glabrous on both sides; racemes dense, spike-like. 



Petals, except the banner, purplish. 



Petals all greenish-yellow. 



V. Dikfusab 

 Calyx -lobes much shorter than the tube; racemes terminating the branches. 

 Leaf-rachis distinctly winged, constricted at the nodes. 



Plant annual, diffusely branched; racemes 2^4-flowered. 

 Plant perennial, with ascending branches; racemes 5-10-flowered. 

 Leaf-rachis not winged, merely slightly margined. 

 Racemes head-like or subumbellate. 

 Racemes more or less elongate, not head-like. 



Racemes 2-5-flowered, lax; plant diffusely branched above. 

 Racemes many-flowered, dense; plant with ascending branches. 

 Racemes short; plant decumbent or spreading. 

 Racemes elongate; plant tall, erect. 

 Calyx-lobes equaling the tube. 

 Branches glabrous. 



Racemes short, at the ends of short leafy branches. 

 Racemes very long, on naked peduncles opposite the leaves. 

 Branches strigose. 



VI. Unikoliatae 

 Flowers 6-7 mm. long; calyx 3.5-4 mm. long, its lobes lanceolate. 

 Flowers about 4 mm. long; calyx about 2.5 mm. long, its lobes ovate. 



VII. VETULAE 

 One species. 



VIII. Calycosae 

 Leaves glabrous. 

 Stem glabrous. 



Leaflets 17-37, less than 2 mm. long. 

 Leaflets 5-7, usually 3-4 mm. long. 

 Stem hirsute. 

 Leaves and stem strigose-canescent. 

 Calyx-lobes nearly equal. 



Flowers 8-10 mm. long; leaflets 15-29. 

 Flowers about 6 mm. long; leaflets 9-17. 

 Calyx-lobes unequal, the lowest one much longer. 



30. P. oatlala. 



20. P. Hcgcwischiana. 



21. P. viridi flora. 



22. P. minutiflora. 



23. P. nutans. 



24. P. graciUima. 



25. P. diffusa. 



26. P. dispansa. 



27. P. submontana. 



28. P. crenulala. 



29. P. elongata. 



30. P. oculala. 



31. P. unifoliata. 



32. P. Greenmaniana. 



33. P. rctula. 



34. P. filiciformis. 



35. P. Berlandieri. 

 6. P. procumbens. 



36. P. calycosa. 



37. P. Orcullii. 



38. P. alamosana. 



IX. LachnostachvdEs 

 Plant villous. 



Bracts ovate; stem erect, conspicuously glandular-pustulate. 39. P. lachnostachys. 



Bracts lanceolate to linear-lanceolate; stem glandular-punctate but not 

 conspicuously pustulate. 

 Plant shrubby,' erect; calyx 1 cm. long or more. 40. P. sericocalyx. 



Plant decumbent or prostrate, rarely ascending ; calyx 3-8 mm. long. 

 Calyx 6-8 mm. long; corolla 5-8 mm. long. 

 Stem long-pilose. 



Leaflets elliptic, rounded at the apex; banner acutish; 



wings broadest at the base. 41. P. longipila. 



Leaflets cuneate-obovate, truncate or retuse at the apex; 

 banner rounded at the apex; wings broadest at or 

 above the middle. 

 Stem sparingly pilose; bracts narrowly linear-lanceo- 

 late, long-attenuate; corolla not shorter than the 

 calyx; wings usually retuse. 42. P. pilosa. 



Stem densely pilose; bracts lanceolate, acute; corolla 



shorter than the calyx; wings rounded at the apex. 43. P. mollissima. 

 Stem densely short-pilose; banner and wings acutish, the 



latter broadest near the base. 44. P. neomexicana. 



Calyx 3-4 mm. long; corolla about 4 mm. long. 45. P. mollis. 



Plant glabrous up to the inflorescence. 46. P. erythrorhiza. 



