PAPILIOXACEAE 135- 



16. Astragalus. 550. 



Stems slender, the internodes nearly as long as the leaves. 

 Flowers 6-S mm. long, pods 4-6 mm. long. 



Leaflets narrowly linear, 2-2.5 mm. long. 4. A. microlobus. 



Leaflets linear or linear-oblong, 8-15 mm. long. 4. A. microlobus. 



Flowers 8-10 mm. long, pods 15-25 mm. long. 3. A. flexuosus. 



Stems generally stout, the internodes much shorter than the leaves. 



Leaflets linear filiform 1. A. pectinatus. 



Leaflets oblong or elliptic. 



Flowers in elongated spikes or racemes, pods sessile or stipitate. 

 Flowers yellow or white. 



Leaflets less than 2 cm. long, pods stipitate. 



11. A. drummondii^ 

 Leaflets over 2 cm. long. 



Flowers in loose spikes, pods stipitate. 12. A. racemosus. 



Flowers indense spikes, pods sessile. 16. A. carolinianus. 



Flowers violet. 



Stems tall, erect, leaflets over 1.5 cm. long, pod stipitate. 



2. A. bisulcatus. 

 Stem very short, leaflets less than 1.5 cm. long, pod sessile. 



15. A. mollissimus. 

 Flowers in heads or short spikes or racemes, pods sessile. 



Stem 1-6 cm. high, erect ascending or spreading, pods 2-celled. 

 Flowers purplish or violet-purple. 



Peduncles longer than the leaves, pod deeply furrowed. 

 Leaflets over 1.5 cm. long, calyx and pod appressed pube- 

 scent. 13. A. adsurgens. 

 Leaflets less than 1.5 cm. long, calyx and pod loosely 

 villous. 14. A. goniatus. 

 Peduncles equaling or shorter than the leaves, pod not fur- 

 rowed. 17. A. crassicarpus. 

 Flowers yellow, sometimes tipped with purple. 



Slightly pubescent, pod glabrous, 25 mm. long, or more. 



A. mexicanus. 

 Villous pubescent, pods pubescent, 12 mm. long. 



19. A. plattensis. 

 Stems very short, plants sub-acaulescent, sometimes longer in 

 A. missouriensis; pod 1-celled. 

 Flowers purple, plant silky-canescent. 



Short stemmed, peduncles generally exceeding the leaves. 



7. A. missouriensis. 

 Acaulescent, peduncles generally shorter than the leaves. 



6. A. shortianus. 

 Flowers yellow, plant appressed-cinerous or hirsute. 



Cinerous with appressed hairs, peduncles usually 3-8 cm. 



long. 8. A. lotiflorus. 



Very hairy with spreading hairs, flowers usually sub-sessile 



in the axils. 9. A. nebraskensis. 



1. Astragalus pectinatus (Hook.) Dougl. 



Ctenophyllum pectinatum (Hook.) Rydb. 

 Rare in the western part of the state. Scott Bluffs County. 



