PAPJLIONACEAE. 553 



4-6 mm. long; leaflets 11-21, narrowly linear, distant, obtuse; flowers purple, 

 6-8 mm. long, in narrow elongated racemes; pods sessile, pendent, straight, 

 ellipsoid, appressed-pubescent with white hairs, especially on the ventral side, 

 transversely veined, 4-6 mm. long. Prairies, Minn, to S. Dak., Mo., Colo, and 

 Wyo. May-June. 



17. Astragalus microlobus A. Gray. Notched-leaved Milk Vetch. 

 (I. F. f. 2 141.) Finely canescent, about 3 dm. high. Stipules ovate-lanceolate, 

 acute, 3-4 mm. long; leaflets 7-17, linear or linear-oblong, truncate or emarginate, 

 narrowed at the base, 9-15 mm. long; flowers in loose spikes; peduncles often 

 longer than the leaves; pod sessile, ovoid or ellipsoid, reflexed, finely pubescent, 

 transversely veined, flattened on the back, keeled along the ventral suture, 4-6 mm. 

 long. Plains. Neb. to Mo. and Colo. Similar to A. gracilis. Summer. 



18. Astragalus flexuosus (Hook.) Dougl. Flexile Milk Vetch. (I. F. f. 

 2142.) Finely pubescent, 3-5 dm. high. Stipules ovate or ovate-lanceolate, 

 4-6 mm. long; leaflets 9-21, linear, oblong or oblanceolate, obtuse or emarginate, 

 narrowed or cuneate at the base, 6-12 mm. long ; peduncles exceeding the leaves ; 

 flowers purplish, 9-11 mm. long ; pod sessile, cylindric, linear or linear-oblong, 

 dehiscent, pointed, 16-25 mm. long. Plains, Minn, and Neb. to Colo, and the 

 N. W. Terr. June-Aug. 



19. Astragalus distortus T. & G. Bent Milk Vetch. (I. F. f. 2143.) 

 Sparingly pubescent or glabrate, diffuse or ascending; stems 2-4 dm. long. Leaf- 

 lets 11-25. obovate or oval, emarginate or rounded at the apex, narrowed at the 

 ba-e. 4-1 1 mm. long; flowers in loose short spikes; pod sessile, slightly inflated, 

 linear-oblong, coriaceous, strongly curved, 2.5-4 cm. long. In dry soil, 111. to 

 Iowa. Kans., W. Va., Miss, and Tex. March-July. 



20. Astragalus elegans (Hook.) Britton. Pretty Milk Vetch. (I. F. f. 

 2144.) Glabrous or finely strigose, erect or ascending, 2.5-5 dm. high. Stipules 

 ovate, acute, about 4 mm. long; flowers 6-8 mm. long, in elongated racemes; 

 leaflets 9 17, oblong or linear-oblong, 16-20 mm. long; pod ellipsoid, pendent, 

 slightly inflated, obtuse at each end, apiculate, black-pubescent all over, 58 mm. 

 long. Quebec. Lab., the Saskatch. region and in the higher and northern Rocky 

 Mts. June-Aug. 



21. Astragalus Bodini Sheldon. Bodin's Milk Vetch. Finely strigose ; 

 stems 3-10 dm. long. Stipules ovate, acute; flowers 8-10 mm. long in dense racemes; 

 calyx sparingly black-strigose; leaflets 11-15, oval, 8-15 mm. long, acute at both 

 ends; pod ellipsoid, somewhat flattened on the dorsal side, finely black-strigose, 

 obtuse, 7-10 mm. long. River valleys, from W. Neb. to Wyo. and Colo. June- 

 Aug. 



22. Astragalus Robbinsii (Oakes) A. Gray. Robbins' Milk Vetch. (I. F. 

 f. 2146.) Glabrous or nearly so, erect, slender, 2.5-4.5 dm. high. Stipules ovate- 

 oblong, membranous, 4-6 mm. long; leaflets 9-25, oblong, obtuse or slightly 

 emarginate, 9-17 mm. long; flowers 6-1 1 mm. long in loose racemes; pod much 

 flattened, oblong, short-stipitate, rather abruptly pointed at each end, membranous, 

 finely blackish-pubescent, dehiscent, nearly straight, 18-25 mm - l° n g- ^ n rock\ 

 places, Vt. and N. H. June-July. 



23. Astragalus alpinus L. Alpine Milk Vetch. (I. F. f. 2147.) As 

 cending or decumbent, 1.5-4 dm. high, slightly pubescent, or glabrous. Stipules 

 ovate, foliaceous, 4-6 mm. long; leaflets 13-25. oval or elliptic, obtuse or retuse, 

 6-12 mm. long; flowers violet, the keel commonly darker, in short racemes; pe- 

 duncles mostly exceeding the leaves; pod membranous, stipitate, pendent, dehis- 

 cent, rather densely black-pubescent, oblong, acute, somewhat inflated, about 13 

 mm. long; calyx dark-pubescent. On rocks, N. N. Eng. to Newf. and Lab., west 

 to Alaska and Br. Col., south in the Rocky Mts. to Colo. Also in northern Europe 

 and Asia. June. 



24. PHACA L, 



Perennial herbs, similar to A.stragalu*. mostly with pinnate leaves, and racemed 

 or spicate purplish or purple flowers. Pod much inflated, membranous in texture, 

 strictly i-celled, neither of the sutures intruded. [Greek, Lentils.] A large genus, 

 mainly of the north temperate zone. Besides the following, numerous other species 

 occur in the western parts of N. Am. 



