304 



PAPILIONACEAE. 



[Vox,. II. 



22. Astragalus Robbinsii (Oakes) A. Gray. 

 Robbins' Milk Vetch. (Fig. 2146.) 



Phaca Robbinsii Oakes, Hovey's Mag. Hort. 7: 179. 1841. 

 Astragalus Robbinsii A. Gray, Man. Ed. 2, 98. 1856. 

 Astragalus Robbinsii Jesupi Eggleston & Sheldon, Bull. Geol. 

 Nat. Hist. Surv. Minn. 9: 155. 1894. 



Glabrous or nearly so, erect, slender, branched at the base, 

 9 x -i8' high. Stipules ovate-oblong, membranous, 2 // ~3 // 

 long; leaflets 9-25, oblong, obtuse or slightly emarginate at 

 the apex, narrowed or rounded at the base, 4 // -8 // long; 

 flowers white or purple, $"-5" long in loose short or 

 elongated racemes; pedicels i // -2 // long; pod much flattened, 

 I -celled, oblong, short-stipitate, rather abruptly pointed at 

 each end, membranous, finely blackish-pubescent, dehiscent, 

 nearly straight, not furrowed, 9"- 12" long. 



In rocky places, Vermont and New Hampshire. June-July. 



23. Astragalus alpinus L. Alpine Milk 

 Vetch. (Fig. 2147.) 



Astragalus alpinus L. Sp. PI. 760. 1753. 

 Phaca astragalina DC. Astrag. 64. 1803. 



Ascending or decumbent, branched from the base 6'- 

 J 5' high, slightly pubescent, or glabrous. Stipules ovate, 

 foliaceous, 2 // ~3 // long; leaflets 13-25, oval or elliptic, 

 obtuse or retuse, narrowed or rounded at the base, 3'Mi" 

 long; flowers violet, the keel commonly darker, in short 

 racemes; peduncles mostly exceeding the leaves; 

 pod i-celled, somewhat flattened, membranous, stipitate, 

 pendent, dehiscent, rather densely black-pubescent, ob- 

 long, acute, somewhat inflated, about 6" long, deeply 

 furrowed on the under side; calyx dark -pubescent. 



On rocks, northern New England to Newfoundland and 

 Labrador, west to Alaska and British Columbia, south in the 

 Rocky Mountains to Colorado. Also in northern Europe and 

 Asia. June. 



24. PHACA L. Sp. PI. 755. 1753. 



Perennial herbs, similar to Astragalus, mostly with pinnate leaves, and racemed or spi- 

 cate 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 North America. 

 Leaflets 7-21, oblong, elliptic or ovate. 



Pod stalked; flowers slender-pedicelled. i. P.Americana. 



Pod sessile; flowers short-pedicelled. 2. P. neglecta. 



Leaflet only i, or sometimes 3-5, very narrowly linear. 3. P. longifolia. 



i. Phaca Americana (Hook.) Rydberg. Arctic 

 Milk Vetch. (Fig. 2148.) 



Phaca frig ida var. Americana Hook. Fl. Bor. Am. x: 140. 



1830. 

 Astragalus frigidus var. Americanus S. Wats. Bibl. Index, 



i: 193. 1878. 



Erect, nearly simple, glabrous, i-2 high. Stipules 

 foliaceous, ovate-oblong, 2 // -6 // long; leaflets 7-17, oval 

 or ovate-lanceolate, 9 // -i8 // long; peduncles generally ex- 

 ceeding the leaves; flowers white, 8 // ~9 // long, in 

 loose racemes; pedicels filiform, %' long in fruit; pod i- 

 celled, stipitate, inflated, membranous, io // -i2 // long, 

 acute at each end, oblong, dehiscent at maturity, glabrous, 

 shining. 



In wet rocky places, Quebec and arctic America to British 

 Columbia and Alaska, south in the Rocky Mountains to Colo- 

 rado. June-July. 



