372 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



6. Astragalus carolinianus L. Belton, in low woods and in thickets along river, 

 B. C. to N. Mex., Fla., and Que. {A. canadensis L.) — Stems stout, 30 to 80 cm. high; 

 leaflets 15 to 25, oval to oblong, 2 to 4 cm. long, nearly glabrous; flowers 1.5 cm. long, 

 in dense racemes; pod 1 to 1.5 cm. long, terete or nearly so, thick, glabrous, long- 

 beaked. 



7. Astragalus americanus (Hook.) Jones. Frequent on the east slope at low alti- 

 tudes, in thickets and along streams. Yukon to Wyo. and Que. {Phaca americana 

 Rydb.)— Stems stout, erect, clustered, 30 to 80 cm. high; leaflets 7 to 17, oval or 

 oblong, 2 to 4 cm. long, obtuse; flowers yellowish white, 12 mm. long, in dense 

 racemes; pods glabrous, about 2 cm. long. 



8. Astragalus aboriginum Richards. Trail to Iceberg Lake, on open bank. Yukon 

 to Nev., Colo., and Sask. {Atelophragma aboriginum Rydb.) — Stems tufted, ascend- 

 ing, 20 to 30 cm. long, short-hairy; leaflets 9 to 15, narrowly oblong, 1 to 2 cm. long, 

 acute or obtuse; flowers yellowish white, 1 cm. long, in loose racemes; pod 1.5 to 2 

 cm. long, slender-stalked, acute. 



9. Astragalus forwoodii S. Wats. Occasional on the east slope at low altitudes, on 

 open brushy hillsides. Mont., Wyo., and S. Dak. {Atelophragma forwoodii Rydb.) — 

 Stems ascending, tufted, 10 to 30 cm. long; leaflets 9 to 17, oblong, 1 to 1.5 cm. long, 

 acute or obtuse; flowers 7 to 8 mm. long, yellowish white, tipped with purple, in 

 loose racemes; pod 1.5 to 2 cm. long, slender-stalked. 



10. Astragalus drummondii Dougl. Occasional on the east slope at low altitudes, 

 on open hillsides. Alta. to N. Mex. and Nebr. {Tium drummondii Rydb.)— Stems 

 erect, 30 to 60 cm. high, stout, hairy; leaflets 25 to 31, oblong, obtuse, about 1 cm. 

 long; flowers 1.5 to 2 cm. long, cream-colored; pods 2 to 2.5 cm. long, slender-stalked. 



11. Astragalus vexilliflexus Sheld. Common on the east slope at low altitudes, on 

 prairie or open hillsides, or in thickets. B. C. to Wyo. and Sask. {Homalohus vexilli- 

 flexus Sheld.)— Stems slender, ascending or prostrate, 10 to 30 cm. long, often forming 

 dense mats; leaflets 7 to 11, oblong, 3 to 12 mm. long, densely covered, at least 

 beneath, with appressed haii's; flowers purplish, 8 mm. long, in loose racemes; pod 

 about 3 mm. wide, sessile. 



12. Astragalus goniatus Nutt. Occasional on the east slope at low altitudes, on 

 open or brushy hillsides. B. C. to N. Mex. and Sask.— Stems 10 to 20 cm. high, 

 densely tufted, ascending; leaflets 15 to 21, oblong, obtuse, 5 to 12 mm. long; flowers 

 1.5 cm. long, purple, in dense headlike spikes; calyx usually with black hairs; pod 

 about 1 cm. long, white-hairy. 



13. Astragalus missouriensis Nutt. Belton, on dry gravel bank. Mont, to N. Mex. 

 and Kans. {Xylophacos missouriensis Rydb.)— Stems 5 to 10 cm. long, densely 

 clustered; leaflets 11 to 21, elliptic or obovate, 5 to 15 mm. long; flowers pm-ple, in a 

 short dense raceme; pod 7 to 8 mm. mde, long-beaked. 



8. OXYTROPIS DC. Locoweed. 



Perennials; leaves often all basal, with numerous leaflets; flowers usually in dense 

 spikes, purple or yellowish white; pods mostly sessile, often partially 2-celled. — 

 Some, at least, of the species of this genus are poisonous to stock, causing temporary 

 paralysis or sometimes death. 



Stems leafy; pods drooping 1. O. deflexa. 



Stems naked; pods erect. 



Leaflets whorled 2. O. splendens. 



Leaflets opposite or alternate, not whorled. 



Flowers 1 to 4, on a stalk 4 cm. high or less 3. O. parryi. 



Flowers usually more than 4, often very numerous, on a stalk 5 to 30 cm. high. 

 Leaflets and stems with numerous viscid glands; corolla purplish, at least 

 when withered 4. O. viscida. 



