140 



FABACEAE 



Calj'x-teeth about one-fourth as long as the tube; corolla about 12 mm. 

 long. 6. C. araneosum. 



Pod 1-1.5 cm. long. 7. C. salinum. 



20. ONIX Stev. 



1. O. Mulfordae. 



21. GEOPRUMNON Rydb. Buffalo Beans, Ground Plums, Buffalo 

 Peas, Prairie Apples. 



Pods pubescent, abruptly pointed. 1. G. plattcnse. 



Pods glabrous, pointless. 



Corolla purple: leaflets oblong to linear. 2. G. crassicarpum. 



Corolla yellowish-white, with purple keel; leaflets oval or obovate. 



3. G. succulentum. 



22. ASTRAGALUS (Tourn.) L. Loco Weed, Milk Vetch. 



Plants cespitose, subscapose, \'illous-pubescent ; pods sulcata on both sutures. 



I. Mollissimi. 

 Plants with elongate leafy stems. 



Pods not sulcata or slightly so on the lower suture, round or nearly so in cross-section. 



II. UUGINOSI. 



Pod deeply sulcate on the lower suture, cordate or triangular in cross-section. 



Leaves and stems strigose or glabrata; pods several-seeded. III. Hypoglottides. 

 Leaves and stem villous; pods few-seeded. IV. Spaldixgl\ni. 



I. Mollissimi. 

 Pod glabrous, deeply sulcata. 

 Pod villous, slightly sulcata. 



Cal.vx densely villous; leaflets 6-12 pairs. 

 Pods perfectly 2-celled; raceme elongate. 

 The cells of the pod confluent at the apa.x ; raceme short. 

 Calyx sparingly nigrescent; leaflets 3-6 pairs. 



1. A. mollissimus. 



2. A. Bigelovii. 



3. A. Thompsonae. 



4. A. anisus. 



II. Uliginosi. 

 Pod straight or nearly so. 



Caly.x-tube 4-6 mm. long, 3-4 mm. wide. 



Bracts linear-lanceolate, long-attenuate, the lower almost as long as the calyces; 

 calyx-teeth all narrow, subulate, fully half as long as the tube; pod glabrous. 



5. A. canadensis. 

 Bracts ovate to lanceolate, scarcely half as long as the calyces; calyx-teeth short, 

 less than half as long as the tube, the upper broader; pod more or less 

 hairy (except "sometimes in the first). 

 Upper calyx-taeth only slightly broader than the lower; bracts lanceolate. 

 Calyx not black-hairy; pod not sulcate. 6. A. oreophilus. 



Calyx more or less black-hairy; pods somewhat sulcata on the lower suture. 



7. .4. Mortoni. 

 Upper calyx-teeth about twice as broad as the lower, 

 the base; pod not sulcata. 

 Calyx-tube about 3 mm. long, less than 2 mm. wide. 

 Pod decidedly arcuate. 



III. Hypoglottides. 

 Pod with appressed gray or black pubescence. 

 Calyx-teeth short and broad; corolla purple. 

 Calyx-teeth subulate. 



Corolla piu-pla or pink, seldom white; caly.x-teeth much shorter than the tube. 



11. A. striatus. 

 Corolla sulphur-yellow, white, or pinkish; calyx-teeth almost equaUing the tube. 

 Leaflets elliptic, appressed-pubescent. . 12. A. sulpfiuresccns. 



Leaflets broadly obovate; pubescence looser. 13. A. oreganus. 



Pod villous with long spreading hairs. 



Corolla ocliroleucous ; bracts broadly spatulate to linear, obtuse. 



14. A. virgultulus. 

 Corolla purple; bracts ovate-lanceolate or oblong-lanceolate, often acutish. 



Calyx biack-hairy; teeth decidedly shorter than the tube. 15. A. goniatus. 

 Calyx not black-hairy; teeth about equalling the tube. 16. A. agrestis. 



broadly triangular at 



A. spicatus. 



A. ursinus. 



A. palans. 



9. 

 18. 



10. A. terrninalis. 



One species. 



IV. Spaldixgiaxi. 



17. A. Spaldingii. 



23. HAMOSA Medic. 

 Plant acaulescent, silvery white. 



Racemes several-flowered; calyx-teeth triangular-lanceolate, about one-tliird as long 



as the tube. 1. //• scaposa. 



Racemes 1-2-flowered; calyx-teeth elongate-lanceolate, more than half as long as the 

 tube. 2. H. calycosa. 



Plant caulescent, not silvery. 

 Legume curved. 



Plant glabrous or strigose. 



Pod less than 3 mm. wide, not mottled; corolla 5-6 mm. long. 



Leaflets lanceolate or oblong ; pod finely strigose. 3. H. austrina. 



Leaflets cuneate or oblong, emarginate; pod glabrous. 4. H. Nuttalliana. 



