FABACEAE 



629 



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. P. microphyllus. 



Calyx merely ciliate : leaflets 13-17. 3. P. phleoides. 



Leaflets 3-11. 



Spikes cylindric or oblong. 



Standard with a relatively narrow blade cuneate or constricted at the 



base. 4. P. albidus. 



Standard with a very broad blade cordate at the base. 



Bracts with long-acuminate tips. 5. P. candidus. 



Bracts with short tips. 



Stems and branches prostrate-spreading : spikes mainly 1-2 cm. long. 6. P. gracilis. 

 Stems and branches erect or ascending : spikes mainly 2-3 cm. long. 7. P. oligophyllits. 

 Spikes globular or ovoid. 8. P. multiflorus. 



Corolla colored, usually pink, rose or purple. 

 Upper leaves with 11-31 leaflets. 



Foliage densely villous. 9. P. griseus. 



Foliage glabrous or minutely pubescent. 



Calyx silky-villous : annual. 10. P. emarginatus. 



Calyx glabrous ; perennial. 



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

 sistent bracts. 11. P. foliosus. 

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

 ciduous bracts. 12. P. Sabinalis. 

 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. P. purpurcus. 



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



spikes loose. 14. P. Pvrterianua. 



Bracts with pubescent tips. 



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



leaflets obtuse. 15. P. tenui/olius. 



Tips of the bracts much longer than the bodies : pubescence 



gray : leaflets acute. 16. P. Oattingeri. 



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



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. P. Stanfleldii. 



Spikes Over 1 cm. thick, stout : calyx 4 mm. long. 20. P. tennis. 



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



flat blades 1-4 mm. wide. 21. P. decumbens. 



Calyx glabrate or merely ciliate. 1 



Spikes, or the most them, cylindric. 22. P. carneus. 



Spikes subglobose. 23. P. Feayi. 



1. Fetalostemon 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 the 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, with long fili- 

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

 gular, barely 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 subulate-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. 



