504 FABACEAE 



1. X. stipularis (M. E. Jones) Rydb. Stems 5-15 cm. long; leaflets 9-17, 

 elliptic to obovate, 8-15 mm. long, rounded or retuse at the apex, silky beneath, 

 glabrate above; raceme subcapitate, 5-12-flo\vered; calyx siUcy-villous with white 

 hairs; tube about 1 cm. long, teeth lance-subulate, 4-5 mm. long; corolla purple, 

 about 2 cm. long; pod 2.5-3 cm. long, 8-10 mm. thick, rounded at the base, 

 short-acuminate at the apex, reticulate, glabrate. Astragalus arieiinus stipu- 

 laris M. E. Jones. Hills: s Colo. Suhmont. Je, 



2. X. cuspidocarpus (Sheld.) Rydb. Stems 1-2 dm. high, decmnbent at 

 the base; leaflets 10-17, oblong to obovate, 8-12 mm. long, usually retuse, gla- 

 brous above, strigose beneath; raceme 7-9-flowered, subcapitate; cal^Tc-teeth 

 subulate, 1.5 mm. long; corolla ochroleucous, tinged with purple; legumes 2.5-3 

 cm. long, abruptly acute at both ends. A, cuspidocarpus Sheld. A. thermalis 

 Greene. Hills: Mont. — n Wyo. Suhmont. — Mont, My-Je. 



3. X. cibarius (Sheld.) Rydb. Stems 1-3 dm, long, decumbent at the base, 

 strigose and striate; leaflets 11-17, oblong-obovate to nearly orbicular, rounded 

 or retuse at the apex, 5-15 mm. long, glabrous above, strigose beneath; raceme 

 short, 8-12 flowered; calyx-tube 6-8. mm. long; teeth subulate, 2 mm. long; 

 corolla 12-lS mm. long, purplish or ochroleucous, with purple-tipped keel; pod 

 cross-reticulate; lower suture sulcate. A. ciharius Sheld. A. arieiinus M. E. 

 Jones. Hills; Utah — Colo. — Mont. Suhmont. 



4. X. aragalloides Rydb, Stems 1 dm. or less long, decumbent at the base; 

 leaflets 11-19, lanceolate to elliptic, silky-canescent, 5-12 mm. long, acute; 

 raceme short, 4r-10-flowered; calyx ascending, strigose with black and white 

 hairs; tube about 8 mm. long; teeth subulate, 3.5-4 mm. long; corolla purphsh, 

 about 2 cm. long; pod about 4 cm. long, tapering, rather deeply sulcate below, 

 transversely reticulate; upper suture prominent. Arid regions: s Utah. L.Son. 



6. X. amphioxys (A. Gray) Rydb. Stems spreading, 1-5 cm. long; leaflets 

 15-25, obovate or oval, 4r-10 mm. long; raceme short, S-12-flowered; calyx 

 strigose with mixed white and black hairs; tube 7-8 mm. long; teeth subulate, 

 about 2 mm. long; legume crescent-shaped, acute at both ends, 3-5 cm. long, 

 strigose, cross-reticulate; lower suture deeply sulcate. A. amphioxys A. Gray. 

 Gravelly hills : Tex.-M3olo. — ^Utah — (? Ida.) — Ariz. Son. 



6. X. eurekensis (M.E.Jones) Rydb. Stems less than 1dm. high, sometimes 

 almost wanting; leaflets elliptic or oval, about 1 cm. long, coarsely silky; calyx 

 6 mm. long; teeth subulate; corolla about 25 mm. long; keel tipped with purple; 

 pod 3-5 cm. long, acuminate, appressed long-hairy, sulcate on both sutures. A. 

 glareosus M. E. Jones. A. eurekensis M. E. Jones. Valleys and hillsides among 

 sage brush: Utah. Son. My. 



7. X. Shortianus (Nutt.) Rydb. Stem 1-10 cm. long; leaflets 11-15, 

 obovate or oval, 1-2.5 cm. long; pedimcles shorter than the leaves; raceme 

 short, 5-15-flowered; calyx strigose, usually with white hairs; tube 8-10 mm. 

 long; teeth lance-subulate, about 3 mm. long; corolla violet or purple, 18-25 mm. 

 long; pod elongate-ovoid, arcuate, 3-5 cm. long, 12-14 mm. wide, sulcate on 

 the lower suture, strigose. A. Shm-tianus Xutt. Plains and mesas: Neb. — 

 Ariz. — Wyo. Plain — Mont. My-Je. 



8. X. Zionis (M. E, Jones) Rydb. Stems spreading or prostrate, 5-30 cm. 

 long; leaflets about 21, ovate to lanceolate, about 12 mm. long, acute; peduncles 

 as long as the leaves; calyx-tube about 6 mm. long; corolla pink-purple; legume 

 arcuate, abruptly long-acuminate, about 3 cm. long, slightly sulcate, triangular 

 in cross-section; ventral suture prominent. A. Zionis M. E. Jones. Sandy or 

 gravelly places ; Utah. Son. — S uhmoni. Mr-My. 



9. X. puniceua (Osterhout) Rydb. Stems decumbent, about 4 dm. long; 

 leaflets elhptic or oblong, 8-lo mm. long, rounded or retuse at the apex, ashy- 

 pubescent beneath, sparingly strigose above; raceme about 10-flowered; calyx 

 silky-hirsute; tube 5-6 mm. long; teeth subulate, 2 mm. long; corolla purple, 

 about 15 mm. long; pod elongate-ovoid, 15-20 mm. long, 7 mm. wide, pubes- 

 cent; lower suture slightly sulcate. A, puniceus Osterhout. Dry hills: Colo. 

 Suhmont. Je. 



