144 FABACE.\E 



Stipe 5-7 mm. long; leaflets narrowly linear: stem glabrous or nearly so; 

 calyx-teeth usually nearly equalling the tube. 18. H. stipilatus. 



Legume strigose. 19. //. strigulosus. 



III. Debiles. 

 Stem very slender, filiform and decumbent; pod sessile, ovate or oval. 



20. H. debilis. 

 Stem erect or ascending; pods stipitate and long-acute at both ends. 



21. H. Bourgovii. 



IV. CAilPESTRES. 



Corolla ochroleucous, usually without any tinge of purple; upper leaves reduced to fili- 

 form phyllodes or the rachis greatly produced, without a terminal leaflet: canescent 

 riish-like plants, with deep-seated roots and stem branched below tlie surface; 

 caly.\-lobes less than half as long as the tube. 

 Calyx more or less black-hairy; legumes tapering towards the base. 



Calyx-lobes subulate, much longer than broad; leaves Unear-subulate to linear, 



very acute. 22. II. campestris. 



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

 obtiLse. 23. H. junciformis. 



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

 to fiUform. 24. H. junceus. 



Coralla white, pink, purpUsh, or rarely ochroleucous, 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 piilvinate-cespitose. 7. H. detritalis. 



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



25. H. decumbens. 

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

 Leaflets strigose on both sides, usually densely canescent. 

 Leaflets narrowly Linear or narrowly lance-Unear. 



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



high. 26. H. strigosits. 



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

 the keel tipped with piu-ple; plant less than 2 dm. high. 



27. H. tenuifoliiis. 

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

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



Leaflets usually glabrous above, green. 



Calyx wliite-hairy , its teeth one-third as long as the tube; leaflets linear 



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



Calyx usually 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 elUptic 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 racliis. 32. H. paucijugus. 



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

 Legumes linear with parallel sutures, 3 mm. wide. 



33. II. microcarpus. 

 Legumes obUquely oblanceolate, fully 3.5 mm. wide near the 

 apex. 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 linear or narrowly lance-linear. 35. H. PalUseri. 

 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. 

 Calyx-teeth obtuse; leaflets many, the terminal one present. 37. H. stenophi/Uus. 

 Calyx-teeth very acute; leaflets "few, the terminal one wanting or continuous with the 

 rachis. 38. H. Episcopus. 



VI. COLI.INI. 



Pod straight. 39. H. coUinus. 



Pod curved one-half to two-thirds of a circle. 40. H. curvicarpus. 



VII. Flexuosi. 

 Pod oblong, over 5 mm. in diameter. 



Inflorescence short; flowers about 15 mm. long; pod glabrous. 41. H. Ilallii. 

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



42. H. Fendleri. 

 Pod linear, 2-3 mm. in diameter. 



Pod abruptly contracted into a short or obsolete stipe. 



