PEA FAMILY 505 



10. X. argophyllus (Nutt.) Rydb. Stems short, decumbent, 5-10 cm. 

 long; leaflets 15-17, lanceolate, 8-15 mm. long, acute; raceme 3-8-flowered; calyx- 

 tube 8-10 mm. long; teeth subulate, about 4-5 mm. long; corolla 15-20 mm. long, 

 purplish; pod oblong-ovoid, with a curved point, about 2 cm. long, transversely 

 wrinkled, rounded on both sutures. A. argophyllus Nutt. Hills and valleys: 

 Mont. Wyo. Utah Nev. Submont. Je-Jl. 



11. X. uintensis (M. E. Jones) Rydb. Stems prostrate or decumbent, 

 5-10 cm. long; leaflets lance-oblong to elliptic, 5-10 mm. long, acute; raceme 

 short, few-flowered; calyx-tube about 8 mm. long; teeth subulate, 1.5-2 mm. 

 long; corolla purple, 2-2.5 cm. long; pod ovoid, 2-2.5 cm. long, obcompressed; 

 ventral suture slightly sulcate. A. uintensis M. E. Jones. Dry ground: Colo. 

 Nev. Ariz. Son. Submont, My-Je. 



12. X. vespertinus (Sheld.) Rydb. Stems 4-6 cm. high, decumbent, 

 striate; leaflets 11-13, obovate-elliptic, obtuse, 4-12 mm. long; raceme short, 

 3-6-flowered; calyx strigose with mixed black and white hairs; tube about 8 mm. 

 long; teeth subulate, about 1.5 mm. long; corolla 2-3 cm. long, purplish; pod 

 2.5-3 cm. long, coriaceous, oblong, obcompressed-triangular in section; upper 

 suture prominent. A. vespertinus Sheld. (?) A. panguicensis M. E. Jones. Dry 

 hills: Colo. N.M. Submont. My. 



13. X. missouriensis (Nutt.) Rydb. Stems 5-10 cm. long; leaflets 11-21, 

 elliptic to obovate, 5-15 mm. long; raceme short, 5-1 5-flowered ; calyx-tube 7-8 

 mm. long; teeth subulate, 2-2.5 mm. long; corolla purple, 15-20 mm. long; pod 

 oblong, 1.5-2.5 cm. long, 7-8 mm. broad, neither suture sulcate, rather prom- 

 inent in age. A. missouriensis Nutt. Plains and hills: Sask. Kans. N.M. 

 Mont. Plain Mont. My-Je. 



14. X. cymboides (M. E. Jones) Rydb. Stems decumbent, 5-15 cm. long, 

 and matted; leaflets 9-11, elliptic, obtuse, usually about 6 mm. long; calyx-tube 

 about 6 mm. long; legume oblong-ovoid, 6 mm. wide, 16 mm. long, somewhat 

 4 -angled, with rather prominent sutures in age. A. cymboides M. E. Jones. 

 Gravelly or clayey ground: Utah. Submont. Je-Jl. 



15. X. pygmaeus (Nutt.) Rydb. Plant almost stemless; leaflets 7-11, 

 broadly oval, obovate, or orbicular, 5-10 mm. long; raceme short, subcapitate, 

 few-flowered; calyx strigose with short, partly black hairs; tube about 8 mm. 

 long; teeth 2 mm. long; corolla ochroleucous or purple, about 1.5 cm. long; pod 

 obliquely ovoid, 2-3 cm. long, somewhat mottled, pulpy when young, in age 

 with a membranous, transversely reticulate outer coat and a thicker inner 

 one. Phaca pygmaea Nutt. Astragalus Chamaeluce A. Gray. A. CicadaeM. E. 

 Jones. Hills: Colo. Wyo. Utah. Submont. My. 



16. X. musinensis (M. E. Jones) Rydb. Plant nearly acaulescent; leaf- 

 lets 1-3, lanceolate, or elliptic-lanceolate, 2 cm. or less long; pod ovate, 18 mm. 

 long, 6-8 mm. broad, strigillose, with incurved acute apex, sulcate ventrally at 

 the base; outer coat loose. A. musinensis M. E. Jones. Clayey slopes: Utah. 

 Submont. Je. 



17. X. Newberryi (A. Gray) Rydb. Subacaulescent; leaflets 3-7, obovate, 

 6-10 mm. long; raceme short, 2-6-flowered; calyx-tube about 12 mm. long; teeth 

 subulate, 3 mm. long; corolla 2.5-3 cm. long, ochroleucous, tipped with purple; 

 pod ovoid, about 2 cm. long, somewhat curved, not sulcate. A. Newberryi A. 

 Gray. Dry hills: sw Colo. N.M. Ariz. Utah. Son. Ap. 



18. X. consectus (Sheld.) Rydb. Subacaulescent; leaflets 5-11, oblance- 

 late, acute, 1-2 cm. long; raceme short, 6-8-flowered; calyx-tube about 10 mm. 

 long; teeth subulate, 3-4 mm. long; corolla about 2 cm. long, purplish or ochro- 

 leucous tipped with purple; legume ovoid, about 2.5 cm. long, with rather long 

 beak, neither suture sulcate. A. consectus Sheld., in part. A. eriocarpum M. 

 E. Jones, not S. Wats. Dry ground: Utah. Son. Submont. Ap-My. 



19. X. Watsonianus (Kuntze) Rydb. Subacaulescent; leaflets broadly 

 obovate-cuneate, rounded or retuse at the apex, 10-15 mm. long; flowers capi- 

 tate; calyx villous with black hairs; tube 12-15 mm. long; teeth subulate, 5 mm. 

 long; corolla purplish, nearly 3 cm. long; pod 2.5 cm. long, strongly curved above 



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