142 FABACEAE 



Corolla yellow. 3. C. flavus. 



Corolla pinkish. 4. C. conferiiflorus. 

 Calyx silky-pilose or liirsute with long loose hairs. 



Corolla purple; calyx-teeth 4-5 mm. long. 5. C. argillosus. 



Corolla oclu'oleucous ; calyx-teeth 2 mm. long. 6. C. urceolatus. 



30. XYLOPHACOS Rydb. Sheep-pod. 



Pod strigose or glabrous. 



Exocarp of the fruit not spongy; stem evident, but often short. 

 Pod more or less curved. 



Plant sparingly hairy or glabrous, scarcely canescent; stem usually more or 

 less elongate. 

 Calyx-tube about 10 mm. long, white-hairy; plant sparingly silky. 



1. X. slipularis. 

 Calyx-tube 5—8 mm. long, black-hairy; plant strigose or glabrous. 



Pod 2-2.5 cm. long, abruptly acute at both ends. 2. X. cuspidocarpus. 

 Pod 2.5-4 cm. long, long-acuminate at both ends. 3. X. cibtirius. 

 Plant densely canescent, with white silky appressed hairs; stem low, decumbent. 

 Pod elongate: dorsal suture distinctly sulcate. 

 Pod tapering at the base, not very thick. 



Calyx-teeth subulate, about half as long as the tube. 



4. X. aragalloides. 

 Calyx-teeth less than half as long as the tube. 5. X. amphiozys. 

 Pod not tapering at the bases. 



Calyx with black hairs; leaflets oval; corolla white or cream-colored. 



6. X. eurekensis. 

 Calyx without black hairs; leaflets rounded-obovate ; corolla purple. 



7. X. Shortianus. 

 Pod short-ovoid; neither suture distinctly sulcate. 



Pod mottled. 



Pod very strongly curved and vertically flattened at the middle; 



leaflets oval, acute, strigose. 8. X. Zionis. 



Pod shghtly curved; leaflets oblong, rounded or truncate at the 

 apex, AiUous. 9. X. puniceus. 



Pod not mottled, slightly curved and tiu-gid. 



Calyx-teeth subulate, about half as long as the tube; leaflets oblong- 

 oval. 10. A. argophyllus. 

 Cal.vx-teeth lanceolate, one-fourth as long as the tube; leaflets 

 obovate. 11. X. uinlensis. 

 Pod straight or nearly so; plant canescent. 



Pod obcompressed, somewhat triangular; ventral sutiu-e only prominent. 



12. X. vespertinus. 

 Pod compressed; both sutures prominent. 



Corolla piu-ple; calyx with black hairs. 13. X. missouriensis. 



Corolla white or ochroleucous with purple-tipped keel; calyx without black 

 hairs. 14. X. cymboides. 



Exocarp of the fruit spongy at least m. age; plant sub-acaulescent, less than 5 cm. 

 high. , 



Leaflets 7-11, rounded-obovate, obtuse. 15. X. pygmaeus. 



Leaflets 1-3, broadly lanceolate, acute. 16. X. musinensis. 



Pod ^illous. 



Pod densely woolly, short-ovoid; plant canescent. 

 Pubescence of the leaves strictly appressed. 



Leaflets elliptic to obovate; calyx-teeth one-fourth as long as the tube. 

 Leaflets obovate, obtusish; peduncles much shorter than the leaves. 



17. X. Newberryi. 

 Leaflets oblanceolate, acute; peduncles about equalling the leaves. 



18. X. conseclus. 

 Leaflets broadly obovate-cuneate, rounded, truncate, or retuse at the apex; 



calyx-teeth half as long as the black-villous tube. 19. X. Walsonianus. 



Pubescence of the leaves loosel.v woolly. 



Stems 1 dm. long or less; bracts ovate or oblanceolate, only slightly exceed- 

 ing the pedicels. 

 Leaflets broadly obovate, roimded at the aoex; plant densely floccose. 



20. X. utahensis. 

 Leaflets oblanceolate or oblong, acute; plant hirsute- villous. 



Corolla ocliroleucous; only the keel purple-tipoed. 21. X. Purshii. 

 Corolla purple. 22. X. glareosus. 



Stems 2-4 dm. high; bracts subiflate, at least half as long as the calyx. 



23. X. inflexus. 

 Pod sparingly villous, elongate; plant not canescent. 24. X. Parryi. 



31. MICROPHACOS Rydb. 



Pod slightly sulcate on the lower suture, transversely veined; leaflets narrowly linear- 

 obtuse. 1. M. parviflorus. 



Pod merely flattened on the lower suture, cross-wrinkled ; leaflets linear-oblong or linear , 

 cuneate, truncate or emarginate. 2. M. microlobus. 



32. PTEROPHACOS Rydb. 1. P. tetraptems. 



33. ATELOPHRAGMA Rydb. 



Pod stipitate, flat. 



Partial partition broad, making the pod almost 2-celled. 1. A. Arthuri. 



