490 FABACEAE 



22. P. jejuna (S. Wats.) Rydb. Pulvinate-cespitose; stems 1-4 cm. long, 

 densely covered by scarious stipules and numerous leaves; leaves 1-3 cm. long, 

 stiff; leaflets 11-15, linear, 2-4 mm. long, strigose; peduncles 1-3 cm. long, 1-3- 

 flowered; calyx strigose; tube 1 mm. long; teeth subulate, 1 mm. long; corolla 

 purple, 5 mm. long; legume about 1 cm. long, mottled, puberulent. A. jejunus 

 S.Wats. Dry hills : Wyo. Utah. Submont. My-Au. 



23. P. humillima (A. Gray) Rydb. Pulvinate-cespitose; stems 1-2 cm. 

 long, covered by scarious stipules; leaves 1-3 cm. long; rachis persistent and 

 more or less pungent; leaflets 9-11, oblong, canescent, 1-2 mm. long; peduncles 

 short, 1-3-flowered; calyx-teeth subulate, half shorter than the tube; corolla 

 pale; legume ovoid, 4-6 mm. long, white-pubescent. Dry table land: Colo. 

 Submont. Je-Jl. 



24. P. Beckwithii (T. & G.) Piper. Cespitose perennial; stems glabrous, 

 2-4 dm. high, branched; leaflets obovate, 6-12 mm. long, glabrous, rounded or 

 retuse at the apex; raceme short, many-flowered; calyx glabrous or minutely 

 black-hairy; tube 4-5 mm. long; teeth subulate, 3-5 mm. long; corolla 18-20 

 mm. long; stipe of the pod 5 mm. long; body lance-oblong, about 2 cm. long, 

 mottled; upper suture prominent, wing-margined; lower suture strongly curved, 

 rounded or even somewhat sulcate. A. Beckwithii T. & G. Gravelly hillsides: 

 Utah Ida. Nev. Submont. My-Je. 



25. P. artemisiarum (M. E. Jones) Rydb. Resembling the preceding; 

 stems erect, 2-3 dm. high; leaflets 13-25, rhombic-obovate, 8-12 mm. long, 

 rounded or retuse at the apex, glabrous; raceme 6-10-flowered; calyx with scat- 

 tered short black hairs; tube 5-6 mm. long; teeth subulate, 2 mm. long; corolla 

 purple, about 18 mm. long; pod as in the preceding but thicker and said to be 

 filled with a mucilaginous pulp when young. A. Beckwithii artemisiarum M. 

 E. Jones. Mountains: w Utah. Son. Je. 



26. P. pubentissima (T. & G.) Rydb. Perennial, with a taproot; stems 

 much branched from the base, grayish strigose, about 1 dm. high; leaflets 7-17, 

 obovate to oblong, obtuse, densely canescent-hirsute ; calyx grayish hirsute; 

 tube 3 mm. long; teeth subulate, 2 mm. long; corolla 8 mm. long; keel tipped 

 with purple; legume obliquely ovoid, strongly curved, 1-5 cm. long, silky- 

 hirsute. A. pubentissimus T. & G. (?) A. Peabodyanus M. E. Jones. Dry hills: 

 Utah Wyo. Colo. Son. Submont. My. 



27. P. annua Geyer. Annual; stem 1 dm. high or less, branched, erect; leaf- 

 lets linear to oblong, 5-15 mm. long, grayish strigose, truncate, rounded or re- 

 tuse at the apex; racemes short, 3-6-fl owered ; calyx-tube 1-1.5 mm. long; teeth 

 subulate, 1 mm. long; corolla ochroleucous, 5 mm. long; legume obliquely ovoid, 

 1.5 cm. long; finely strigose. A. Geyeri A. Gray. Sandy flats and banks : Wyo. 



Ore. Calif. Son. Submont. Je-Jl. 



28. P. sabulonum (A. Gray) Rydb. Annual; stem branched, 1 dm. high or 

 less; leaflets 9-13, oblong, 8-15 mm. long, hirsute-canescent; racemes short, 3-5- 

 flowered; calyx hirsute-canescent; tube 2 mm. long; teeth subulate, 2-2.5 mm. 

 long; corolla about 6 mm. long; legume obliquely ovoid, 15 mm. long, hirsute. 

 A. sabulonum A. Gray. Sandy ridges: Nev. Utah. Son. 



29. P. elatiocarpa (Sheld.) Rydb. Perennial, with a taproot; stems numer- 

 ous, a few centimeters long; leaflets oblong or lance-oblong to obovate, strigose on 

 both sides or glabrate above; peduncles of the earlier flowers 1-3 cm. long, of the 

 later scarcely any; calyx hirsute-strigose; tube 3 mm. long; teeth subulate, 3 

 mm. long; corolla ochroleucous, about 1 cm. long; legume elongate-ovoid, hir- 

 sute-strigose. A. latiflorus brachycarpus A. Gray. A. elatiocarpus Sheld. Plains: 

 Sask. Minn. Tex. N.M. Mont. Plain. My-Au. 



30. P. lotiflora (Hook.) Nutt. Perennial, with a taproot; stems many, 1 

 dm. or less long, hirsute; leaves 5-10 cm. long; leaflets oblong or lanceolate, 

 acute, 8-15 mm. long, light green, silky-hirsute beneath, glabrate above; peduncles 

 1-8 cm. long; raceme 3-12-flowered; calyx silky-hirsute; tube campanulate, 3 

 mm. long; teeth subulate, 4 mm. long; legume elongate-ovoid, 2 cm. long, 8 

 mm. thick, hirsute-villous; upper suture acute, straight. A. lotiflorus Hook. 

 Hills and plains: Sask. Neb. Colo. Wyo. Plain. My-Je. 



