496 FABACEAE 



alike. Pods linear, laterally flattened, dehiscent, membranous, completely 2- 

 celled by the intrusion of the lower suture. Seeds numerous. 



Plant acaulescent, silvery white. 



Racemes several-flowered; calyx-teeth triangular-lanceolate, about one-third as long 



as the tube. I. H. scaposa. 



Racemes 1-2-flowered; calyx-teeth elongate-lanceolate, more than half as long as the 

 tube. 2. //. calycosa. 



Plant caulescent, not silvery. 

 Legume curved. 



Plant glabrous or strigose. 



Pod less than 3 mm. wide, not mottled: corolla 5-6 mm. long. 



Leaflets lanceolate or oblong; pod finely strigose. 3. H. auslrina. 



Leaflets cuneate or oblong, emarginate; pod glabrous. 4. //. Nutlalliana. 

 Pod 6 mm. wide, mottled; corolla about 1.5 cm. long. 5. H. ampleia. 



Plant hirsute; pod over 4 mm. wide. 6. H. malacra. 



Legume straight. 



Racemes short, subcapitate; corolla light bluish purple; leaflets oblong to obcor- 



date, green. 7. //. leplocarpa. 



Racemes elongate, lax; corolla cream-colored; leaflets narrowly oblong or linear, 

 graj-ish strigose. 8. II. atratiformis. 



1. H. scaposa (A. Gray) Rydb. Cespitose, nearly acaulescent perennial; 

 leaflets 5-9, obovate or elliptic, silvery-cinereous, 7-12 mm. long; peduncles 

 8-10 cm. long; raceme 3-12-flowered; calyx ci,nereous; tube about 5 mm. long; 

 teeth 1-1.5 mm. long; corolla purple, about 12 mm. long; pod oblong, slightly 

 curved, cinereous-strigillose, 12-15 mm. long, 4 mm. wide. Astragalus scaposus 

 A. Gray. Sandy soil: Wyo.—N.M.— Ariz.— Utah. Son. Ap-Je. 



2. H. calycosa (Torr.) Rydb. Cespitose perennial, nearly acaulescent; 

 leaflets 3-9, obovate, oblanceolate, or oblong, silvery-sericeous, 5-10 mm. long; 

 peduncles 2-5 cm. long; raceme 1-3-flowered; calyx cinereous; tube 4 mm. long; 

 teeth lanceolate, 2-4 mm. long; corolla purple or cream-colored, about 1 cm. 

 long; pod sessile, cinereous-strigillose, oblong, somewhat curved, 15-20 mm. long, 



4 mm. wide. A. calycosus Torr. A. brcvicaulis A. Nels. Gravelly soil: Ida. 

 —Utah— Calif. Submont.—Mont. Ap-Jl. 



3. H. austrina Small. Annual; stem branched at the base; branches 

 ascending or decumbent, 1-4 dm. long, strigillose; leaflets 9-11, strigose on both 

 Slides, oblong or oval, 2-6 mm. long; peduncles 1-4 cm. long; raceme head-like, 

 few-flowered; calyx-tube 2 mm. long; teeth subulate, 2 mm. long; corolla purplish, 

 5-6 mm. long; pod linear, 1.5-2 cm. long, strongly curved at the base. A. 

 NuUallianus trichocarpus T. & G. Plains and prairies: Tex. — Utah — Calif.; 

 n Mex. Son. Ja-Je. 



4. H. Nuttalliana (DC.) Rydb. Annual; stem simple or branched at 

 the base, erect or ascending, sparingly strigillose or glabrate, 0.5-3 dm. high; 

 leaflets 11-21, oblong, obovate or cuneate, usually notched at the apex, 2-10 

 mm. long, glabrous or sparingly strigose; peduncles 2-5 cm. long; raceme short 

 and few-flowered; calyx-tube and the lance-subulate teeth each about 2 mm. 

 long; corolla purplish, 5-6 mm. long; pod Hnear, about 2 cm. long, slightly curved, 

 glabrous. A. NuUallianus DC. Dry soil: Ark.— Colo.— Ariz.— Tex. Son. 

 Mr-My. 



5. H. amplexa (Payson) Rydb. Biennial or short-lived perennial; stems 

 several, 3-4 dm. high, sparingly pubescent, erect or spreading, flexuose; leaflets 

 17-21, 'oblanceolate, truncate or retuse at the apex, 9-12 mm. long, 4-6 mm. 

 wide; raceme 12-15-flowered; calyx-tube 6 mm. long, nigrescent; teeth hnear, 

 2-3 mm. long; corolla violet; pod sparsely pubescent, 2-2.5 cm. long, 6 mm. wide, 

 mottled along the dorsal suture, curved. A. amplexus Payson. Dry hillsides: 

 w Colo. Suhmont. My. 



6. H. malacra (A. Gray) Rydb. Perennial, cespitose; stems 1-3 dm. high, 

 decumbent or erect, hirsute; leaflets 13-15, obovate, retuse, 1-1.5 cm. long, 

 villous-hirsute; peduncles longer than the leaves; calyx-tube black-hairy, nearly 

 1 cm. long; teeth subulate, 3 mm. long; corolla purple, fully 1.5 cm. long; pod 

 flattened laterally, stronglv curved, loosely villous-hirsute, 3 cm. long, about 



5 mm. wide, somewhat mottled. A. malacrus A. Gray. A. obfalcatus A. Nels. 

 Hills: Calif.— Nev.— Ida.— Ore. Son. Ap-My. 



