PEA FAMILY 521 



17. A. Bigelovii (A. Gray) Greene. Leaflets 9-17, lanceolate or oblong- 

 lanceolate, acute at both ends, 2-3 cm. long, 5-8 mm. wide, green, short-strigose 

 on both sides; peduncles 2-3 dm. high, finely strigose; raceme 1-2 dm. long; 

 flowers more or less spreading; calyx-tube about 7 mm. long; teeth lanceolate^ 

 2-3 mm. long; corolla purple, 20-22 mm. long; wings very broad, slightly emargin- 

 ate; legume stipitate, ascending, lance-cylindric, about 3 cm. long, fully half 

 2-celled. Oxytropis Lambertii Bigelovii A. Gray. Plains and hillsides: w Tex. 

 s Colo. Submont, Mont. Je-Jl. 



18. A. plattensis (Nutt.) Rydb. Leaflets 11-15, elliptic or oblong-lanceo- 

 late, 4-10 mm. long, densely silky-canescent, with rather loose hairs, acute; 

 scape 4-8 cm. long, with rather loose hairs; raceme 3-5 cm. long; calyx-tube 

 5 mm. long; teeth subulate, 2 mm. long; corolla purple, about 12 mm. long; 

 legume villous, about 15 mm. long, coriaceous, half 2-celled. 0. plattensis Nutt 

 Dry hills: Wyo. Neb. Submont. Je. 



19. A. monticola (A. Gray) Greene. Leaflets 7-11, elliptic, or oblong, 6-20 

 mm. long, sericeous-canescent; scape 5-15 cm. high; raceme short, 3-6 cm. long; 

 calyx densely and finely silky-strigose; tube 5 mm. long; teeth triangular, 1.5 

 mm. long; corolla purple, 12-15 mm. long; wings slightly emarginate; legume 

 erect, lance-cylindric, nearly 2 cm. long, long-acuminate, ratherthin, sulcate on 

 the upper suture, 2-celled. O. monticola A. Gray. Dry plains and bottom land: 

 Wyo. Colo. Submont. Jl. 



20. A. sericeus (Nutt.) Greene. Leaflets 7-13, elliptic or oblong, 1-3 cm. 

 long, shining, with white silky-appressed hairs; scape 1-1.5 dm. high, stout; 

 raceme 5-10 cm. long; flowers rather spreading; calyx about 7 mm. long; teeth 

 lanceolate, about 3 mm. long; corolla light purple; wings very broad and deeply 

 emarginate; pod cylindric, erect, about 2 cm. long, long-acuminate, nearly 2- 

 celled. 0. sericea Nutt. Hills: Neb. Colo. Wyo. Plain. My-Jl. 



21. A. albertinus Greene. Leaflets 17-23, lanceolate, broadest near the 

 base, 15-20 mm. long, sparingly silk}' and light green above, densely silky be- 

 neath, the margins somewhat involute; scape slender, 1-2 dm. high; raceme about 

 1 dm. long; calyx short-silky, with rather loose hairs; tube 5-6 mm. long; teeth 

 2-3 mm. long; corolla about 15 mm. long, white below, sky-blue at the end; pod 

 lance-ovoid, erect, dark, long-acuminate, thin, half 2-celled. Exposed rocky 

 places: Man. Sask. Plain. Au. 



22. A. dispar A. Nels. Leaves spreading or ascending; leaflets 9-17, elliptic 

 or oblong, acutish at both ends, 1-2 cm. long, 4-6 mm. wide, those of the lower 

 leaves often shorter and broader, somewhat silvery, with closely appressed hairs; 

 scape 1-1.5 dm. high; raceme short; bracts linear-lanceolate to lanceolate, 5-8 

 mm. long; flowers usually spreading; calyx sparingly appressed-silky with short 

 hairs, often somewhat tinged with purple above; tube 5-7 mm. long; teeth subu- 

 late, 3 mm. long; corolla dark bluish purple to rarely ochroleucous, about 15 mm. 

 long; wings broad, slightly emarginate; keel with a very dark purple spot; pod 

 ascending-spreading, thin-coriaceous, nearly straight, less than 2 cm. long, long- 

 acuminate, minutely strigose, half 2-celled. A. patens Rydb. A. formosus 

 Greene, a coarse form. Plains and hills: N.D. Neb. Colo. Wyo. Plain 

 Submont. My-S. 



23. A. angustatus Rydb. Leaflets 7-13, narrowly linear-lanceolate to 

 narrowly linear, 1-2 cm. long; scape about 1 dm. high; raceme 3-5 cm. long; 

 calyx finely silky-strigose; tube 5-6 mm. long; teeth subulate; wings broad and 

 slightly emarginate; legume ovoid, coriaceous, half 2-celled. A. Aven-Nelsonii 

 Lunell. Plains and hills: N.D. Neb. Colo. Plain Submont. Jl-Au. 



24. A. Lambertii (Pursh) Greene. Leaflets 11-17, narrowly lanceolate, 

 1.5-4 cm. long, 3-5 mm. wide, acute at both ends, green, silky on both sides; 

 scape 1.5-2 dm. high; racemes elongate, 5-10 cm. long; flowers usually some- 

 what ascending; calyx-tube about 7 mm. long; teeth subulate, 2 mm. long; 

 corolla usually dark bluish purple; wings slightly emarginate; legume almost 

 erect, lance-oblong, half 2-celled. Oxytropis Lambertii Pursh. A. falcatus 

 Greene. Dry plains and prairies: Minn. Mo. Colo. Mont. Plain Sub- 

 mont. My-Au. 



