136 KEY AND FLORA 
palmately compound, with 3-5 linear to obovate-oblong leaflets, cov- 
ered with glandular dots. Flowers 4-} in. long, loosely racemed. 
Pod rough with glands. Prairies W. 
3. P. argophylla Pursh. Sitver-LEAvED PsoraLea. Densely 
silvery downy, with white, close-lying hairs. Stem often zigzag, 1-3 
ft. high. Leaves palmate; leaflets 3-5, elliptical-lanceolate, oval or 
obovate. Spikes interrupted, the peduncles longer than the leaves. 
Flowers blue or purplish, } in. or more long. Pod ovate, beak straight. 
Prairies, especially N.W. 
4. P.esculenta Pursh. Pomme Biancue, Tipsin, Dakota TurRNIp. 
Clothed with roughish hairs. Stem 5-15 in. high, erect and stout, 
Root turnip-shaped, starchy, eatable. Leaves palmately compound, 
with 5 lance-oblong leaflets. Flowers 4 in. long, in a dense ellipsoidal 
spike. Pod hairy, with a pointed tip. High prairies or plains, 
especially N.W. 
XVI. AMORPHA L. 
Small shrubs, glandular-dotted. Leaves odd-pinnate. Flowers 
purple, blue, or white, in slender spikes or racemes. Calyx 
5-toothed, persistent. Standard obovate, concave; wings and 
keel none. Stamens monadelphous, projecting much. Ovary 
sessile. Pod curved, glandular-roughened, 1—2-seeded, never 
opening.* 
1. A. canescens Pursh. Leap Prant, Sox Strings. A bushy, 
white, silky-downy shrub, 1-3 ft. high. Leaflets small and crowded, 
21-49, oval or oblong-elliptical. Spikes mostly clustered at the sum- 
mit, rather showy. Standard bright blue, roundish. Pod 1-seeded, 
slightly longer than the calyx. Prairies. Roots very long and tough, 
hence one common name. 
2. A. microphylla Pursh. A bushy shrub about 1 ft, high. Leaves 
many, short-petioled; leaflets 13-19, rigid, oval or oblong. Racemes 
mostly solitary. Flowers fragrant; standard purplish. Prairies, 
especially N.W. 
3. A. fruticosa L. Fatse Inpico. A shrub, 6-15 ft. high, with 
smooth, dark-brown bark. Leaves petioled; leaflets 15-21, short- 
stalked, oblong, obtuse or notched, sparingly punctate with clear dots. 
Slender flowering spikes, panicled or solitary, 4-6 in. long. Flowers 
blue or purple. Calyx teeth short, nearly equal, downy. Pod glandu- 
lar. River banks.* 
XVII. ROBINIA L. 
Trees or shrubs. Leaves odd-pinnate; stipules often spiny. 
Flowers showy, in axillary racemes. Calyx short, 5-toothed, 
