510 FAB ACE AE 



Calyx-teeth about as broad as long, triangular; leaflets linear or linear-oblong, 



obtuse. 23. H. junciformis. 



Calyx white-hairy; teeth triangular; legumes linear; leaflets, if any, narrowly linear 



to filiform. 24. H. junceus. 



Coralla white, pmk, purplish, or rarely ochroleucons, at least the keel tipped with dark 



purple; terminal leaflet usually well developed; leafy plants with a cespitose cau- 

 dex. 



Legume strigose, rarely becoming glabrate in age. 

 Legume arcuate. 



Leaflets 5 ; plant pulvinate-cespitose. 7. H. detritalis. 



Leaflets 7-11; plant cespitose, decumbent, but not pulvinate. 



2^5 H (f€Cti77ll)€TlS 



Legiime straight, or the end slightly curved upwards in H. oblongifolius. 

 Leaflets strigose on both sides, usually densely canescent. 

 Leaflets narrowly linear or narrowly lance-linear. 



Calyx-teeth almost as long as the tube; corolla purplish; plant 2-4 dm. 

 _, ,lugh. 26. H. strigosus. 



Calyx-teeth much shorter than the tube; corolla ochroleucons, only 

 the keel tipped with purple; plant less than 2 dm. high. 

 T _ 27. H. tenuifoHus. 



Leaflets narrowly lanceolate or lance-oblong, 4-8 mm, long, 1-2.5 mm. 

 wide; plant less than 1 dm. high. 28. H. divergens. 



Leaflets usually glabrous above, green. 



Calj-x white-hairy, its teeth one-third as long as the tube; leaflets linear 



to lance-oblong; racemes long and lax. 29. II. serotinus. 



Calyx usuaUy black-hairy, its teeth fully half as long as the tube. 



Legumes 2-2.5 cm. long; corolla about 1 cm. long; leaflets ample; plant 



erect, 2-4 dm. high. 

 Leaflets elliptic or oblong, obtuse, the terminal one short-stalked 

 and similar to the rest; lower suture of the legume decidedly 

 curved. 30. H, oblongifolius. 



Leaflets lanceolate or oblanceolate, somewhat falcate, the terminal 

 one long-stalked, longer and tapering into the rachis without a 

 distinct articulation. 31. H, decurrens. 



Legumes less than 2 cm. long; corolla 6-8 mm. long; leaflets small, less 



than 1 cm. long; plant decumbent-cespitose. less than 2 dm. 

 high. 



Leaflets 1-5, the terminal narrowly oblanceolate, falcate, gradually 

 tapering into the rachis. 32. H. paucijugus. 



Leaflets 7-17, the terminal one resembhng the rest, short-stalked. 

 Legumes linear with parallel sutures, 3 mm. wide. 



33. H. viicrocarpus. 

 Legumes obliquely oblanceolate. fully 3.5 mm. wide near the 



T 11,^ ^P^^' 34. H. humilis. 



Legume glabrous from the beginning. 



Legumes about 1.5 cm. long; calyx-teeth less than half as long as the tube; leaf- 

 lets hnear or narrowly lance-linear. 35. H. Palliseri. 



Legumes 2-2.5 cm. long; calyx-teeth more than half as long as the tube; leaves 

 lanceolate to oval. 36. H. hylophilus. 



V. Stenophylli. 



CaljTC-teeth obtuse; leaflets many, the terminal one present. 37. H. sienophyllus, 



'^"^ very acute; leaflets few, the terminal one wanting or continuous with the 



38. H. Episcopus. 



^ A ^ • X.^ VI. COIJ^NI. 



Fod straight. 39 jj collinus 



Pod curved one-half to two-thirds of a circle. 46! H\ curvicar'pus, 



VII. Flexuosi. 

 Pod oblong, over 5 mm. in diameter. 



Inflorescence short; flowers about 15 mm. long: pod glabrous. 41. H. Hallii, 

 Inflorescence elongate and lax; flowers about 10 mm. long; pod pubescent. 



TD ^ T « o . ,. 42. H. Fendleri, 



Pod hnear. 2-3 mm. m diameter. 



Pod abruptly contracted into a short or obsolete stipe. 



btem decumbent; stipe minute or obsolete. 43. H. flexuosus. 



Stem erect; stipe almost equalUng the calyx. 44. H. proximus, 



Fod gradually tapering into the short stipe. 45. H. Salidae, 



^ ^ VIII. Macrocarpi. 



une species. 4q jr/ macrocarpus. 



1, H. lingulatus (Sheld.) Rydb. Leaves numerous, simple, 2-3.'5 cm. long, 

 ungulate or linear-spatulate; pedimcles slender, shorter than the leaves, 1-2- 

 floTvered; cal:>-x-tube striate; teeth subulate, spreading; corolla about 1 cm. 

 long. Astragalus lingulatus Sheld. Foot-hills: Wyo. SubmonL 



2, H. exilifolius (A. NeLs.) Rydb. Leaves numerous, narrowly linear to 

 filiform, pungent, 2~A cm. long, sparingly strieose; peduncles about equalling 



racliis. 



