FABACEAE 



629 



9. 



Corolla white or yellowish. 



Foliage densely villous-silky : corolla yellowish. 1. P. obovatus. 



Foliage glabrous or thinly pubescent : corolla white. 

 Leaflets 13-37. 



Calyx pubescent : leaflets 29-37. 2. 



Calvx merely ciliate : leaflets 13-17. 3. 



Leaflets 3-11. 



Spikes cylindric or oblong. 



Standard with a relatively narrow blade cuneate or constricted at the 



base. 

 Standard with a very broad blade cordate at the base. 

 Bracts with long-acuminate tips. 

 Bracts with short tips. 



Stems and branches prostrate-spreading : spikes mainly 1-2 cm. long. 

 Stems and branches erect or ascending : spikes mainly 2-3 cm. long. 

 Spikes globular or ovoid. 

 Corolla colored, usually pink, rose or purple. 

 Upper leaves with li-31 leaflets. 

 Foliage densely villous. 

 Foliage glabrous or minutely pubescent. 



Calyx silky-villous : annual. 10. 



Calyx glabrous : perennial. 



Leaflets of an oblong type : calyx 4 |mm. long, about equalling the per- 

 sistent bracts. 11. 

 Leaflets of a linear type : calyx 3 mm. long, much surpassed by the de- 

 ciduous bracts. 12. 

 Upper leaves with 3-9 leaflets. 

 Calyx copiously pubescent. 



Pubescence of the calyx villous or silky-villous. 



Leaflets linear or nearly so : bracts surpassing the buds. 

 Bracts with glabrous or merely puberulent tips. 



Upper part of the plant with gray pubescence : calyx not ribbed : 



spikes dense. 13. 



Upper part of the plant with tawny pubescence : calyx ribbed : 



spikes loose. 14. 



Bracts with pubescent tips. 



Tips of the bracts about as long as the bodies: pubescence tawny : 



leaflets obtuse. 

 Tips of the bracts much longer than the bodies : pubescence 



gray : leaflets acute. 16. 



Leaflets oblong or oblanceolate : bracts shorter than the buds. 17. 



Pubescence of the calyx of short close-set appressed hairs. 



Calyx-tube glabrate, glaucous. 18. P. pubescens. 



Calyx-tube copiously pubescent, not glaucous. 



Bracts shorter than the buds, and mature calyx : leaflets with tightly 

 involute- blades, about 1 mm. wide. 

 Spikes less than 1 cm. thick, slender : calyx 3 mm. long 19. 



Spikes over 1 cm. thick, stout : calyx 4 mm. long. 20. 



Bracts longer than the buds, and mature calyx : leaflets with nearly 

 fiat blades 2-4 mm. wide. 

 Calyx glabrate or merely ciliate.' 



Spikes, or the most tliem, cylindric. 22. 



Spikes subglobose. 23. 



P. microphyllus. 

 P. phkoides. 



P. albidus. 



P. candidus. 



P. gracilis. 



P. oUgophyllus. 



P. multiflorus. 



P. giiseug. 

 P. emarginatus. 



P. foliosus. 

 P. Sabinalis. 



P. purpureus. 

 P. Porterianus. 



15. P. tenuifolius. 



P. Gattingeri. 

 P. Reverchonii. 



P. Stanfleldii. 

 P. tenuis. 



21. P. decumbens. 



P. carneus. 

 P. Feayi. 



1. Petalostemon obovatus T. & G. Plant densely villous-silky. Stems erect or 

 ascending, several dm. tall : leaflets 5-9, the blades obovate to elliptic, 8-10 mm. long, 

 truncate or acute at the apex, cuneate to rounded at the base : spikes cylindric, 5-11 cm. 

 long : bracts oval-elliptic, with slender tips : calyx copiously pubescent ; tube somewhat 

 ribbed ; lobes subulate-lanceolate, nearly as long as the tube : corolla yellowish, rather 

 inconspicuous. 



In dry soil, Texas. Spring and summer. 



2. Petalostemon microphyllus T. & G. Plant somewhat villous and glandular. 

 Stems more or less branched at tlie base, the branches erect or ascending, 2-6 dm. tall : 

 leaflets 29-37, the blades oblong to oblong-cuneate, 4-6 mm. long, emarginate, glandular- 

 dotted : spikes narrowly cylindric, 2-5 cm. long : bracts closely pubescent, wdth long fili- 

 form-subulate tips : calyx much shorter than the bracts ; tube campanulate ; lobes trian- 

 gular, barely J as long as the tube : corolla white ; standard with a broadly ovate cordate 

 blade, the other petals with linear or nearly linear blades. 



In dry soil, Texas. Spring and summer. 



3. Petalostemon phleoides T. & G. Plant sparingly villous or glabrate. Stems 

 usually branched at the base, the branches erect or ascending, 3-7 dm. long, simple or spar- 

 ingly branched : leaflets 13-17, the blades oblong to cuneate-oblong, 3-10 mm. long, 

 usually rounded at the apex, glandular beneath, cuneate at the base : spikes cylindric, 

 1.5-6 cm. long: bracts with suljulate-filiform tips, early deciduous: calyx oblique; tube 

 campanulate ; lobes very short, often only ^ or ^ as long as the tube : corolla white ; stand- 

 ard with a hooded cordate blade ; the other petals with linear blades. 



In dry soil, Arkansas and Texas. Spring and summer. 



