PEA FAMILY 481 



lanceolate, 2-3 cm. long, grayish strigose and strongly veined; stem-leaves re- 

 duced to small lance-subulate scales, 3-^4 mm. long; flowers in interrupted spikes 

 terminating the branches; calyx canescent; upper teeth rounded, the lower three 

 broadly triangular; corolla dark blue, 5 mm. long; pod subglobose, 4 mm. thick, 

 canescent. In sand: se Utah. 



2. P. lanceolata Pursh. Stem very glandular-punctate, glabrous or spar- 

 ingly strigose, 1.5-4 dm. high; leaflets 1.5-4 cm. long, strigose with scattered 

 hairs or glabrate; peduncles 1-3 cm. long; calyx-tube 1.5 mm. long, campanulate; 

 lobes ovate, obtuse, 0.5 mm. long; corolla 5-6 mm. long; pod 4 mm. thick. Sandy 

 plains: Sask. Kans. N.M. Ariz. Mont. Plain Submont. My-Au. 



3. P. micrantha A. Gray. Stem very glandular-dotted, glabrous or strigose; 

 leaflets 1-5 cm. long, 1-3 mm. wide, glabrous or nearly so; peduncles 2-4 cm. 

 long; calyx-tube 1 mm. long; lobes rounded-oval, 0.5 mm. long; corolla scarcely 

 5 mm. long. Sandy plains: Okla. Tex. Ariz. s Utah. Son. Ap-Jl. 



4. P. Purshii Vail. Stems adsurgent, branched, sparingly strigose or gla- 

 brate, 1-6 dm. high; leaflets 1.5-4 cm. long, retuse, rounded or acute, and mucro- 

 nate, sparingly strigose or glabrate; peduncles 2-5 cm. long; calyx and corolla as 

 in P. lanceolata; pod 4-5 mm. thick. Sandy soil: Wash. Ida. Ariz. Calif. 

 Son. Submont. My-S. 



6. P. stenostachys Rydb. Stem adsurgent or erect, sparingly strigose and 

 glandular-dotted, 3-5 dm. high, branched; leaflets 2-4 cm. long, rounded to acute 

 and mucronate at the apex, sparingly strigose; peduncles 5-15 cm. long; calyx- 

 tube 1.5 mm. long; teeth 0.5 mm. long; corolla white, 4 mm. long. Sandy soil: 

 Utah. Son. Jl. 



6. P. stenophylla Rydb. Stem simple, about 5 dm. high, slender, sparingly 

 strigose and glandular-dotted; leaflets 2.5-5 cm. long, about 2 mm. wide, spar- 

 ingly strigose; peduncle 8-10 cm. long; calyx-lobes triangular, acute, 0.5 mm. 

 long; corolla about 4 mm. long. Sandy river banks: Utah. Son. Je-Jl. 



7. P. tenuiflora Pursh. Stems erect, diffusely branched, striate and stri- 

 gose; leaflets 1-4 cm. long, glabrous above, strigose beneath; racemes slender, 

 2-10 cm. long, rather few-flowered; calyx strigose, usually purplish; tube 1.5 mm. 

 long; calyx-lobes lanceolate, 1 mm. long, acute; corolla light blue, 4-5 mm. long; 

 pod ovoid, 8* mm. long. Prairies and plains: S.D. Tex. Ariz. Mont. Plain 

 Submont. Je-O. 



8. P. linearifolia T. & G. Stem 4-10 dm. high, widely branching, sparingly 

 strigose; leaflets 2-6 cm. long, 2-3 mm. wide, sparingly strigose beneath, glabrous 

 above; calyx-tube campanulate, 2-2.5 mm. long; teeth lanceolate, acute, 1-1.5 

 mm. long; corolla blue, 7-8 mm. long; pod ovoid, 8 mm. long. Plains and hills: 

 Neb. Ark. Tex. Colo. Plain. Je-S. 



9. P. collina Rydb. Stem 4-6 dm. high, branched, strigose; leaflets oblong- 

 oblanceolate, obtuse, 1.5-2.5 cm. long, glabrous or nearly so above, grayish 

 strigose beneath; bracts lanceolate, 2-4 mm. long; calyx densely silky-strigose; 

 tube and the lanceolate lobes each 2 mm. long; corolla blue, about 6 mm. long. 

 Hills: w Neb. Plain. Jl. 



10. P. argophylla Pursh. Stem erect, 3-6 dm. high, branched above, 

 strigose-canescent; leaflets 1.5-4 cm. long, 6-20 mm. wide, obovate or oval, 

 obtuse, densely white-silky on both sides, or grayish strigose above; spike rather 

 short; calyx silvery; tube about 2 mm. long; upper teeth 2-3 mm. long, lanceolate, 

 the lower one narrower, 6 mm. long, in fruit over 1 cm. long. Prairies and plains: 

 Sask. Wis. Mo. N.M. Alta. Plain. Je-Au. 



11. P. digitata Nutt. Stem erect, simple below, branched above, canescent, 

 3-6 dm. high; leaflets 2-3.5 cm. long, 3-5 mm. wide, densely strigose-canescent 

 beneath, sparingly strigose when young, soon glabrate above; spike lax; bracts 

 5 mm. long; calyx silky; tube in flowers 3-4 mm. long; lobes lanceolate, abruptly 

 acuminate, the upper 2 mm., the lowest one 4 mm. long; corolla 7-8 mm. long, 

 blue; pod ovoid, 6-7 mm. long. P. campestris Nutt. Sandy plains: S.D. 

 Ark. Tex. Colo. Plain. My-Jl. 





