PAPILIONACEAE 115 



2. A. canescens Pursh. Lead Plant. 1°-3° high, white-canes- 

 cent : leaflets 21-51 : spikes numerous, 2^-7^ long : flowers blue.— Fre- 

 quent on prairies and barrens throughout the southern part. June. 



9. PAROSELA Cav. 



Flowers spicate. Petals all on claws, the standard inserted at the 

 bottom of the calyx, and the wings and keel adnate to the stamen-tube. 

 Pods indehiscent and one-seeded. 



1. P. Dalea (L.) Britton. Glabrous annual, l°-2^° high: leaflets 

 13-31, linear-oblong, l^^-2^^ long : flowers in dense spikes, pinkish- 

 white : calyx teeth silky pubescent. — Locally abundant in sandy grounds, 

 especially along the Missouri River. May-September. 



10. PETALOSTEMON Michx. Peairie Clovee. 

 Punctate herbs with flowers in dense spikes. Petals on long claws, the 

 heart-shaped standard inserted at the bottom of the calyx, the claws of 

 the inner petals adnate to the filament tubes, and the five stamens alter- 

 nating with them. Pods included, 1-2-seeded. 



Flowers white ; leaflets oblong. 1. P. candidus. 



Flowers white ; leaflets linear. 2. P. multiflorus. 



Flowers rose-purple. 3. P- purpureus. 



1. P. candidus (Willd.) Michx. l°-3° high, glabrous: leaflets 5-9, 

 oblong, 8^^-12^^ long r spikes oblong : bracts longer than the calyx. — 

 Frequent on prairies throughout the southern part. June-July. 



2. P. multiflorus Nutt. l°-2° high, glabrous : leaflets 3-9, linear, 

 3//_5// iQjjg . spikes subglobose : bracts shorter than the calyx. — Occasion- 

 ally adventized along railroads from Kansas City to Sibley. July-Sep- 

 tember. 



3. P. purpureus (Vent.) Rydb. l°-3° high, nearly glabrous : leaflets 

 3-5, linear, 3^^-9^^ long : spikes oblong : bracts about the length of the 

 silky-pubescent calyx. — With No. 1, but more common. June-July. 



11. ROBINIA L. 



Trees with odd-pinnate leaves and showy racemose flowers. Stamens 

 diadelphous. Pods linear, flat, several-seeded, 2-valved. 



1. R. Pseudacacia L. Black Locust. 20°-50° high : leaflets 9-19, 

 ovate-oblong : flowers white, Q'^-\2'' long, very fragrant : pods smooth, 

 2^-4^ long. — Naturalized in many places, and perhaps native south of 

 Little Blue Tank. May-June. 



12. ASTRAGALUS L. MiLK Vetch. 



Herbs with odd-pinnate leaves and spicateracemose flowers. Keel 

 blunt. Stamens diadelphous. Pods very various, either completely or 

 incompletely 2-celled. 



Flowers greenish-yellow. 1. A. Carol inianus. 



Flowers violet purple. 



Pods oblong, globose. 2. A. crassicarpvs. 



Pods linear-oblong, curved. 3. A. distortus. 



