PEA FAMILY 503 



long; corolla ochroleucous, 12 mm. long. A. urceolatus Greene. Mountains: 

 Colo. Submont. Je. 



30. XYLOPHACOS Rydb. SHEEP-POD. 



Perennial herbs, mostly low, usually copiously hairy, often canescent, with 

 short stems. Leaves alternate, with nearly free and distinct stipules; leaflets 

 few or more numerous, entire. Flowers in short, often subcapitate racemes. 

 Calyx cylindric; lobes much shorter than the tube. Corolla purple, rarely 

 ochroleucous or in one species crimson; banner narrow, slightly longer than the 

 wings. Stamens 10; filaments diadelphous; anthers alike. Pods fusiform, or 

 ovoid, leathery or woody, 1-celled, without partition; the lower suture sometimes 

 slightly silicate. Seeds numerous. 



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. stipularis. 

 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. cibarius. 

 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, amphioxys. 

 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 slightly curved; leaflets oblong, rounded or truncate at the 



apex, villous. 9. X. puniceus. 



Pod not mottled, slightly curved and turgid. 



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

 oval. 10. A. argophyllus. 

 Calyx-teeth lanceolate, one-fourth as long as the tube; leaflets 



obovate. 11. X. uintensis. 



Pod straight or nearly so; plant canescent. 



Pod obcompressed, somewhat triangular; ventral suture only prominent. 



12. X. vespertinus. 

 Pod compressed; both sutures prominent. 



Corolla purple; 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 in 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 villous. 



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. consectus. 

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



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



Pubescence of the leaves loosely woolly. 



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

 ing the pedicels. 

 Leaflets broadly obovate, rounded at the apex; plant densely floccose. 



20. X. utahensis. 

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



Corolla ochroleucous; only the keel purple-tipped. 21. X. Purshii. 

 Corolla purple. 22. X. glareosus. 



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



23. X. inflexus. 

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



