388 



FABACEAE. 



Vol. II. 



2. Orophaca argophylla (Xutt.) Rydb. Sil- 

 very Milk \ elch. I'^ig. 25^x3. 



Phaca argophylla \iitt. ; T. & G. Fl. \. A. i : ,54^. 1838. 



/Islragahis hyaliniis M. E. Jones, I'roc. Cal. Acad. II. 

 5: 648. 1895. 



Orot^liaca argoj^hyUa Uydh. in liritton. Man. Ed. 2, 1067. 

 I SOS- 

 Similar to llu- preceding species, hut tlie leaflets 



relatively shorter and broader. Stipules scarious; 



corolla ahout 5" long, puhescent outside; calyx-teeth 



a little shorter than the tube. 



In dry soil. Nebraska and Wyoming. May-July. 



3. Orophaca sericea (Nutt.) Britton. 



Piiaca scricca -Xutt. ; T. & G. FI. N. A. i : 343. 1838 

 Gray 



Hoary Milk V 



Am. Journ. Sci. 

 Britt. & Brown, 111. FI. 



Astragalus scricoleiiciis A 

 (II.) 33: 410. 1S62. 



'Orophaca sericea Britton. 

 2: 307. 1897. 



Villous-pubescent, densely tufted, and spread- 

 ing on the ground from a deep root, the stems 

 3-4' long. Leaves short-petioled. 3-foliolate ; leaf- 

 lets oblong or oblanceolate, acute or obtusish at 

 the apex, narrowed or cuneate at the base, 2"-s" 

 long; peduncles slender, 2-6-flowered, equalling or 

 exceeding the leaves ; flowers bluish-purple, about 

 3" long; pod i-celled, sessile, ovoid-oblong, coria- 

 ceous, acute, villous-pubescent, about 3" long, 

 partly enclosed by the calyx. 



In dry, sandy or rocky places. Nebraska to Wyo- 

 ming and Colorado. May-July. 



31. OXYTROPIS DC. Astrag. 19. 1802. 



[Ar.\gallus Neck. Elem. 3: 12. Hyponym. 1790.] 



[Spiesia Neck. Elem. 3: 13. Hyponym. 1790.] 



Herbs, sometimes shrubby, and mostly acaulescent. with odd-pinnate leaves, and racemose 

 or spicate flowers. Calyx-teeth neprly equal. Petals clawed; standard erect, ovate or oblong; 

 wings oblong; keel erect, shorter than or equalling the wings, its ape.x mucronate, acuminate 

 or appendaged ; stamens diadelphous ; anthers all alike; style filiform. Pod sessile or stipitate, 

 2-vaIved, i-celled, or more or less 2-celled bj' the intrusion of the ventral suture. [Greek, 

 referring to the sharp-pointed keel of the corolla.] 



About 130 species, natives of the north temperate zone. In addition to the following, some 20 

 others occur in the western and northwestern parts of North America. Type species : Oxylropis 

 montana (L.) DC. 



Leaves simply pinnate. 



Plants I '-4' high ; heads few-flowered. 



Pod membranous, pubescent, much inflated, i -celled. 

 Pod coriaceous, ovoid, little inflated, puhescent, partly 2-celled. 

 Calyx gray-puhescent ; leaflets 7-9. oblong. 

 Calyx dark-pubescent : leaflets 7-21. linear. 

 Plants 6'-i8' hi.eh ; heads or spike-like racemes many-flowered. 

 Sparingly pubescent ; flowers 8"-9" long : pods papery. 

 Silky-pubescent: flowers 9"-i5" long: pods coriaceous. 

 Leaves pinnate, the leaflets verticillate. 



Pod scarcely longer than the calyx, its tip spreading. 

 Pod 2-3 times as long as the calyx, its tip erect. 



1. O. podocarpa. 



2. O. mitlticcps. 



3. O. arctica. 



O. canipestris. 

 O. Laiubcrti. 



6. O. splendeus. 



7. O. Belli. 



