630 FABACEAE 



4. Petalostemon albidus (T. & G.) Small. Plant glabrous. Stems often branched 

 at the base, the branches erect or ascending, 6-10 dm. tall, more or less branched : leaves 

 usually clustered : leaflets 5-7, the blades oblong to oblanceolate, 4-8 mm. long, acute, 

 involute : spikes subglobose to cylindric, 1-2 cm. long, peduncled : bracts narrow, about 

 as long as the calyxes, persistent : calyx glabrous, 2.5 mm. long ; lobes triangular to trian- 

 gular-lanceolate, shorter than the tube : corolla white ; standard usually retuse, the blade 

 slightly broader than the rest of the petals. [P. cwneus /3 albidus T. & G. ] 



On sand hills and in pine lands, Georgia and Florida. Summer. 



5. Petalostemon candidus (Willd. ) Michx. Plant glabrous or nearly so. Stems 

 erect, 3-7 dm. tall, branched at the base or above : leaflets 7-9, the blades linear, oblong, 

 oblanceolate or obovate-oblanceolate, 1-3 cm. long, acute, or mucronulate, glandular be- 

 neath, more or less cuneate at the base : spikes cylindric or oblong-cylindric 2-10 cm. 

 long : bracts lanceolate with subulate tips : calyx shorter than the bract ; tube campan- 

 ulate, angled ; lobes triangular to triangular-lanceolate, slightly pubescent, shorter than the 

 tube : corolla white ; standard with a suborbicular cordate blade ; keel-petals with oval 

 blades, the claws longer than the blades. 



On prairies, Northwest Territory to Minnesota, Indiana. Mississippi, Texas and Colorado. Summer. 



6. Petalostemon gracilis Nutt. Plant glabrous. Stems branched at the base, 

 the branches 3-6 cm. long, slender, simple or branching, decumbent : leaflets 5-7, the 

 blades linear or linear-oblong, rarely oblong-oblanceolate, 6-12 mm. long, acute, involute, 

 distant : spikes oval or ovoid, becoming cylindric, 1-2 cm. long : bracts elliptic, with sub- 

 ulate tips : calyx shorter than the bract ; tube campanulate ; lobes triangular, purple, 

 acute, ciliate, hardly J as long as the tube : corolla white ; standard with a broad cordate 

 blade. 



In sand, Florida to Louisiana. Spring and summer. 



7. Petalostemon oligophyllus (Torr.) Rydb. Plant glabrous. Stems erect, 3-9 

 dm. tall, much branched above, the branches ascending : leaflets firm, 5-9, usually 7, the 

 blades linear, linear-oblong or varying to oblanceolate, 0.5-2 cm. long, acute, or mucronu- 

 late, glandular, sometimes early deciduous : spikes oblong, becoming oblong-cylindric, 2-3 

 cm. long : bracts lanceolate or ovate-lanceolate with filiform-subulate tips : calyx shorter 

 than the bract ; tube campanulate, ribbed ; lobes triangular, often pubescent, acute : corolla 

 white ; standard with a very broad' cordate blade. 



On prairies, South Dakota and Wyoming, Texas, Arizona and Mexico. Spring to fall. 



8. Petalostemon multiflorus Nutt. Plant glabrous. Stems usually several together, 

 rigid, 3-6 dm. tall, much branched throughout : leaflets 3-9, the blades linear to linear- 

 oblong, or oblanceolate, acute or obtuse, glandular on both sides, mostly involute : spikes 

 globular or ovoid, 1-1.5 cm. long : bracts subulate : calyx surpassing the bract ; tube 

 campanulate, ribbed ; lobes triangular, shorter than the tube : corolla white ; standard 

 with an ovate blade cordate or subcordate at the base. 



In dry soil on prairies, Kansas to Texas. Spring and summer. 



9. Petalostemon griseus T. & G. Plant villous. Stems erect or ascending, 2-7 dm. 

 tall, more or less branched : leaflets 9-17, the blades oblong, oblanceolate or linear-oblong, 

 6-12 mm. long, mucronate, glandular, finely pubescent : spikes narrowly cylindric, 2.5-4 

 cm. long : bracts deciduous, with long slender tips : calyx densely pubescent ; tube cam- 

 panulate ; lobes triangular-lanceolate, shorter than the tube : corolla pink or pink-purple ; 

 standard with a broad cordate blade. 



In dry soil, the Indian Territory and Texas. Spring and summer. 



10. Petalostemon emarginatus T. & G. Plant glaucous. Stems branched at the 

 base, the branches decumbent, 2-5 dm. long, simple or sometimes branched : leaflets 15-17, 

 the blades cuneate or narrowly oblong-cuneate, 2-7 mm. long, emarginate at the apex, 

 glandular, rather cuneate at the base : spikes ovoid to oblong-cylindric, 1-3 cm. long : 

 bracts abruptly acuminate, villous : calyx villous ; tube campanulate, oblique ; lobes lanceo- 

 late, acuminate, longer than the tube : corolla deep pink ; standard with an oblong, retuse 

 or truncate blade, the other petals with oblong blades. 



In dry soil, Texas. Spring and summer. 



11. Petalostemon foliosus A. Gray. Plant glabrous. Stems erect or decumbent, 

 3-9 dm. long, simple or branched : leaflets 13-31 , the blades oblong to oblong-oblanceo- 

 late, paler beneath than above : spikes oblong-conic becoming cylindric, 2-5 cm. long : 

 bracts lanceolate, with subulate tips much surpassing the calyxes, persistent : calyx gla- 

 brous, 4 mm. long ; tube obliquely campanulate ; lobes triangular-lanceolate, shorter than 

 the tube, acute : corolla rose-purple ; standard with a very broad cordate blade, the other 

 petals somewhat narrower. 



On river banks, Illinois, Kentucky and Tennessee. Summer. 



