POLTPETALOUS EXOGENOUS PLANTS. 219 



P. CRYPTOCARPA. ^^e»i somewliat divai'icately branched, 

 canescently hairy with an appressed pubescence; leaves 

 5-foliolate; leaflets 1^^" long-, stijjules suhuVdie ; pechmdes 

 longer than the leaves; spikes ovate, compact; hrads lan- 

 ceolate, cuspidate, shorter than the ilower ; c«/_?/a: somewhat 

 inflated, gibbous at the base; legume membranaceous, 

 slightly tipped with the base of the style, not wrinkled. 

 — Drummoml. 



P. ESCULENTA, Pursli. The whole plant hirsute ; stem 

 erect, somewhat branched ; leaves 5-foliolate ; leaflets sligh tly 

 dotted ; spikes capitate ; floiuers pale blue ; vexillum ob- 

 ovate, marked with 2 callosities toward the base; legume 

 covered with the calyx, hirsute; root the size of a walnut, 

 scarcely farinaceous, solid and tough. '"According to 

 Nuttall the root of this species is the Pomme de Prairie 

 (also called Pomme Blanche) of the Canadian voyageurs.'* 

 — Gray and Torrey. In Texas, Dr. Leavenworth. 



*** Leaves pinnate. 



P. SIMPLEX. Grayish pubescent, obscurely glandular, 

 erect ; stem simple, solitary, or two from the same root, 

 l°-3° high; leaves 3-foliolate ; leaflets lanceolate, acute, 

 rngosely veined, mucronate ; peduncles very long; spikes 

 oblong, many-flowered ; hrads linear-lanceolate, acuminate ; 

 teeth oi calyx oblong-triangular, the lowest one longest and 

 acuminate; legumes nearly orbicular; flloiuers purplish. 

 Calyx and petals strongly Yemed.—Dru7nmo?id. 



P. RHOMBiFOLiA. Sparingly pubescent ; stem slender, 

 decumbent, angular ; leaflets ^'-J' long, dotted with 

 scarcely visible glands ; petioles 1-2' long ; spikes 6-8- 

 flowered ; floivers purplish ; calyx hirsute; the teeth (except 

 the lowest one) shorter than the tube; vexillum Q\iO\2iiQ. — 

 Drummond. 



