PEA fa:mily 491 



31. p. sesquiflora (S. Wats.) Rj'db. Cespitose perennial; stems 1 dm. or 

 less long, silky strigose-canescent ; leaflets 5-11, linear-lanceolate, strigose-canes- 

 cent, 5-8 mm. long; racemes 1-2-flowered; calj^c-tube 2.5 mm. long; teeth subu- 

 late, 2.5 mm. long; corolla purple, about 7 mm. long; pod about 1 cm. long, 4 

 mm. broad, minutely strigose, mottled, somewhat curved. A. sesquiflorus S. 

 Wats. Drj'hiUs: s Utah. L. Son. Je. 



19. CYSTIUM Stev. 



Cespitose perennials, ^^nth branched rootstocks. Leaves alternate, odd- 

 pinnate, vrith. several pairs of leaflets, most commonly glabrous or sparingly 

 pubescent. Stems mostly decumbent or prostrate, rarely ascending or erect. 

 Flowers white or purpUsh, in rather few-flowered spikes. Calyx short-cyUndric 

 or campanulate; teeth mostly subulate. Pods membranous, much inflated, 

 ovoid, elhpsoid, or globose, perfectly 2-ceUed by the intrusion of both sutures, 

 several-seeded. 



Plant cespitose, less than 1 dm. high, canescent, nearly stemless; pod not curved. 



1. C. platy trope. 

 Plant with elongate stems, 1^ dm. high. 



Plant silvery canescent-strigose; corolla pinkish. 2. C. Coulteri. 



Plant glabrous or slightly strigose, not silvery. 



Corolla purple. 3. C. diphysum. 



Corolla white or yellowish, purple only at the tip. 

 Pod more than 1.5 cm. long. 



Pod short-ovoid, only slightly curved. 4. C. heliophilum. 



Pod elongate-ovoid, strongly curved. 



Calyx-teeth at least half as long as the tube; corolla 8-9 mm. long. 



5. C lentiginosum. 

 Calyx-teeth about one-fourth as long as the tube; corolla about 12 mm. 

 long. 6. C. araneosum. 



Pod 1-1. .5 cm. long. 7. C. salinum. 



1. C. platjrtrope (A. Gray) Rydb. Stems 1-3 cm. long; leaves crowded at 

 the base; leaflets 7-11, obovate or oblanceolate, 5-10 mm. long; spike few- 

 flowered, capitate; cal^Tc strigose; tube 3 mm. long; teeth subulate, 2 mm. long; 

 coroUa white or yellowish, tipped with purple, 7 mm. long; pod ovoid, 2 cm. long, 

 sessile, cinereous-puberulent, mottled. Astragalus platytropis A. Gray. Moim- 

 tains: Xev. — Mont. Mont. Jl. 



2. C. Coulteri (Benth.) Rj'db. Stem 3-4 dm. high, white silky-strigose, 

 branched; leaflets 9-19, broadly obovate, 8-15 mm. long, roimded or retuse at 

 the apex; spike lax; calyx-tube about 5 mm. long; teeth lance-subulate, 2 mm. 

 long; coroUa about 12 mm. long; pod ovoid, cinereous-strigose, about 2 cm. long. 

 A. Coulteri Benth. Arid regions: s Utah — Ariz. — s Calif. F-Ap. 



3. C. diphysum (A. Gray) Rydb. Stems ascending or decumbent, 2-4 dm. 

 high; leaflets 19-21, oblong or elHptic, glabrous, fleshy, rounded or retuse at the 

 apex, 6-10 mm. long; spike dense, oblong; calyx glabrous; tube 5-6 mm. long; 

 teeth subulate, 2 mm. long; corolla 15 mm. long; pod ovoid, acuminate, and 

 somewhat incurved at the apex, about 2 cm. long, glabrous, somewhat sulcate 

 on both sutures. A. diphysus A. Gray. Hills: X.M. — Colo. — Utah — Ariz. 

 S(m. My-Jl. 



4. C. heliophilum Rydb. Perennial, vrith. a deep taproot and a short cespi- 

 tose caudex; stems decumbent or ascending, sparingly strigose, 1-4 dm. high; 

 leaflets rather fleshy, light green, obovate, sparingly strigose, 7-10 mm. long, 

 rounded, retuse or emarginate at the apex; raceme short, oblong; calyx strigose; 

 tube about 5 mm. long; teeth lance-subulate, 2-3 mm. long; corolla ochroleucous, 

 12-14 mm. long; pod ovoid, acute, somewhat sulcate on both sutures, about 2 

 cm. long, 1 cm. in diameter, short-acuminate. Phaca inepta Rydb., in part. 

 Astragalus ineptus Coult. & Xels. Hills and moimtain sides: IMont. — Wyo. — 

 Utah. Subinont. IMy-Jl. 



5. C. lentiginosum (Dougl.) Rydb. Stems decumbent or diifusely spread- 

 ing; leaflets 11-19, obovate or obcordate to elUptic, 8-12 mm. long, shghtly 

 strigose or glabrate; raceme short and dense; calyx strigose; tube 3-4 mm. long; 

 teeth subulate, 2 mm. long; corolla ochroleucous or white, 8-9 mm. long; pod 



