492 FABACEAE 



about 2 cm. long, usually mottled. A. lentiginosus Dougl. Arid regions: 

 Wash. Ida. Utah Calif. Son. My-Jl. 



6. C. araneosum (Sheld.) Rydb. Stems 2-5 dm. long, decumbent or erect, 

 strigose; leaflets 15-19, fleshy, obovate to oval, rounded or retuse at the apex, 

 7-12 mm. long; spike short, 12-15-flowered; calyx with a few scattered black 

 hairs; tube 4-5 mm. long; teeth subulate, about 1.5 mm. long; corolla whitish, 

 tipped with purple; legumes about 2.5 cm. long, sulcate on both sutures, strongly 

 curved, often mottled. A. araneosus Sheld. Dry plains: c Utah. Son. Sub- 

 mont. Je. 



7. C. salinum (Howell) Rydb. Stems many, ascending or decumbent, 1-3 

 dm. high, sparingly strigose; leaflets 9-17, obovate to oblong, obtuse or retuse, 

 8-12 mm. long, glabrous or nearly so; peduncles shorter than the leaves; calyx- 

 tube 3 mm. long; teeth subulate, less than 2 mm. long; corolla ochroleucous, 

 about 1 cm. long; pod glabrous, ovate, short-acuminate, with the beak curved 

 upwards. A. salinum Howell. Saline soils and river flats: Ore. Ida. Son. 

 Je. 



20. ONIX Stev. 



Cespitose perennials, with rootstocks or caudices. Stem mostly decumbent. 

 Leaves alternate, odd-pinnate, with many leaflets. Flowers racemose, white or 

 purplish. Calyx campanulate or hemispheric; lobes subulate. Pod mostly stip- 

 itate, membranaceous, inflated, but triangular in cross-section, perfectly 2-celled, 

 the upper suture acute, the lower sulcate; seeds many. 



1. O. Mulfordae (M. E. Jones) Rydb. Stems decumbent, 1-2 dm. long; 

 leaflets 13-17, linear, 4-Q mm. long, glabrate; racemes 5-10-flowered; calyx 

 strigose; tube campanulate or hemispheric, 2 mm. long; teeth subulate, 1-1.5 

 mm. long; corolla about 7 mm. long, white; pod strigose; stipe 2-3 mm. long; 

 body 10-12 mm. long; upper suture straight. Astragalus Mulfordae M. E. Jones. 

 Dry ground: Ida. Son. Je. 



21. GEOPRUMNON Rydb. BUFFALO BEANS, GROUND PLUMS, 



BUFFALO PEAS, PRAIRIE APPLES. 



Perennial tufted herbs, with decumbent or ascending stems. Leaves alter- 

 nate, odd-pinnate; leaflets numerous, entire, not notched. Flowers perfect, in 

 dense racemes; calyx deeply campanulate or nearly cylindric, 5-lobed; lobes 

 nearly equal. Corolla white or purplish, rarely ochroleucous; banner with a 

 rather narrow, erect blade, longer than the wings and keel; keel-petals wholly 

 united, not produced into a beak. Stamens 10; filaments diadelphous. Pods 

 globose or ellipsoid, fleshy, becoming spongy, 2-celled, the partition formed by 

 the intruded lower suture, which meets the upper suture. Seeds numerous. 



Pods pubescent, abruptly pointed. 1. G. plattcnse. 



Pods glabrous, pointless. 



Corolla purple; leaflets oblong to linear. 2. G. crassicarpum. 



Corolla yellowish- white, with purple keel; leaflets oval or obovate. 



3. G. succulentum. 



1. G. plattense (Nutt.) Rydb. Stems diffusely branched, 1-4 dm. long, 

 decumbent, strigose; leaflets 13-23, oblong, elliptic or cuneate, 5-15 mm. long, 

 acute, rounded or retuse at the apex; racemes few-flowered, head-like; calyx- 

 tube strigose, 5 mm. long; teeth subulate, 2 mm. long; corolla about 15 mm. 

 long, yellowish white, tipped with parple; pod ovoid, 1-1.5 cm. in diameter. 

 Astagalus plattensis Nutt. Prairies: Ind. Ala. Tex. N.D. Plain. Ap-Je. 



2. G. crassicarpum (Nutt.) Rydb. Stems strigose, branched, prostrate, 

 1-4 dm. long; leaflets 13-27, oblong to linear, 8-20 mm. long, acute or obtuse, 

 strigose beneath, glabrous above; raceme few-flowered; calyx-tube about 5 mm. 

 long, strigose, at least some of the hairs black; corolla violet-purple, 1.5-2 cm. 

 long; pod subglobose, 1.5-2 cm. thick. A. caryocarpus Ker. A. crassicarpus 

 Nutt. Prairies: Man. Mo. Tex. Mont. Plain. Ap-My. 



3. G. succulentum (Richards.) Rydb. Stems prostrate, spreading, branched, 

 2-4 dm. long, finely strigose; leaflets 17-25, elliptic or broadly oblong, obtuse, 



