LEGUMINOS.E. (PULSE FAMILY.) 131 



* * Leaves palmately 3 - 5-foliolate ; roots not tuberous. 



4. P. tenuifiora, Pursh. Slender, erect, much branched and bushy 

 (2-4 high), minutely hoary-pubescent when young; leaflets varying from 

 linear to obovate-oblong (|-1 ' long), glandular-dotted; flowers (2-3" long) 

 in loose racemes ; lobes of the calyx and bracts ovate, acute ; pod glandular. 

 (P. floribunda, Nutt.) Prairies, Minn, to 111., Tex., and westward. June- 

 Sept. 



5. P. argophylla, Pnrsh. Silvery silky-white all over, erect, divergently 

 branched (1-3 high); leaflets elliptical-lanceolate; spikes interrupted; lobes 

 of the calyx and bracts lanceolate. High plains, N. Wise, to Iowa, Kan., and 

 westward. June. Flowers 4 - 5" long. 



6. P. digitata, Nutt. More slender and less hoary, 1-2 high ; leaflets 

 linear-oblanceolate ; bracts of the interrupted spike obcordate; calyx-lobes 

 oblong, acute. Central Kan. to Col. and Tex. 



7. P. lanceolata, Pursh. Glabrous or nearly so, yellowish green, densely 

 punctate ; leaflets 3, linear to oblanceolate ; flowers small, in very short spikes ; 

 calyx 1" long, with short broad teeth. Central Kan. to the Sask. and westward. 



* * * Leaves palmately 5-folioIate ; root tuberous ; spike-like racemes dense. 



8. P. esculenta, Pursh. Roughish hairy all over; stem stout (5-15' 

 high) and erect from a tuberous or turnip-shaped farinaceous root ; leaflets 

 obovate- or lanceolate-oblong ; spikes oblong, long-peduncled ; lobes of the 

 calyx and bracts lanceolate, nearly equalling the corolla (|' long). High 

 plains, Sask. to Wise., Iowa, and Tex. June. The POMME BLANCHE, or 

 POMME I>E PRAIRIE, of the voyageurs. 



9. P. hypogsea, Nutt. Tuber small; nearly acaulesceut, hoary with 

 appressed hairs ; leaflets linear ; spikes short-capitate, on peduncles | - 2' long ; 

 calyx narrow, 3 - 6" long. Central Kan. to Col. and Tex. 



10. P. CUSpidata, Pursh. Stout, tall, from a deep-seated tuber, hoary 

 with appressed hairs; leaflets usually broadly oblanceolate, obtuse; flowers 

 large, the petals (6-8" long) exceeding the lanceolate-lobed calyx Central 

 Kan. to Col. and Tex. 



14. AMOBPHA, L. FALSE IXDIGO. 



Calyx inversely conical, 5-toothed, persistent. Standard (the other petals 

 entirely wanting!) wrapped around the stamens and style. Stamens 10, 

 monadelphous at the very base, otherwise distinct. Pod oblong, longer than 

 the calyx, 1-2-seeded, roughened, tardily dehiscent. Shrubs, with odd- 

 pinnate leaves ; the leaflets marked with minute dots, usually stipellate, the 

 midvein excurrent. Flowers violet or purple, crowded in clustered terminal 

 spikes. (Name, &fj.op<pos, deformed, from the absence of four of the petals.) 

 * Pods 1-seeded ; leaflets small (^' long or less), crowded. 



1. A. canescens, Nutt. (LEAD-PLANT.) Whitened with hoary down 

 (1-3 high); leaflets 15-25 pairs, oblong-elliptical, becoming smoothish 

 above; spikes usually clustered at the summit. Sask. to Ind. and Tex., west 

 to the Rocky Mts. ; also eastward to Ga. 



2. A. microphylla, Pursh. Nearly glabrous throughout, 1 high or 

 less ; leaflets rather rigid ; spikes usually solitary. Sask. to Minn, and Iowa, 

 west to the Rockv Mts. 



