166 FABACEAE. 



Standard 9-10 mm. long : leaflet-blades 

 thin, somewhat pubescent beneath : 

 loment-.ioints angular. 9. M. Dillenii. 



Loments sessile or nearly so. 



Corolla conspicuous: standard 8-10 mm. 

 long : lower calyx-lobes narrow : loments 



4~7-jointed. 10. M. canadensis. 



Corolla inconspicuous : standard 4-5 mm. 

 long : lower calyx-lobes broad : lo- 

 ments 2- or 3-.iointed. 

 Upper calyx-lip entire or sharp-notched : 

 leaflets scabrous or pubescent, and 

 ciliate. 

 Blade of the terminal leaflet fully 

 twice as long as wide : loment- 

 .ioints somewhat rhomboidal. 11. M. rigida. 



Blade of the terminal leaflet little 

 longer than wide : loment-joints 

 rounded. 12. M. ohtusa. 



Upper calyx-lip emarginate, obtuse-lobed : 



leaflets glabrous or nearly so. 13. M. marylandica. 



1. M. nudiflora (L.) Kuntze. Leaves clustered on the short decumbent or 

 ascending stem: leaflets 2-8 cm. long, the blades oval or ovate: standard 8-10 

 mm. long: wings not auricled on the lower side: joints of the loment 3-3.5 mm. 

 wide. — Common, in woodlands and on hillsides. 



2. M. grandiflora (Walt.) Kuntze. Leaves clustered at the end of the short 

 erect stem: leaflets 8-13 cm. long, the blades broadly ovate to orbicular-ovate: 

 standard 7-9 mm. long : wings minutely auricled on the lower side : loment- 

 joints 4.5-6 mm. wide. — Common, in woodlands and thickets. 



3. M. Michauxii Vail. Stems prostrate: stipules ovate: leaflets 3; blades 

 suborbicular, 3-6 cm. long: lateral calyx-lobes lanceolate, longer than the 

 tube, acuminate: standard 9-11 mm. long: loment-joints rounded on one side, 

 half -rhombic on the other, about 3 mm. wide. — Common, in dry open places 

 and on banks. 



4. M. sessilifolia (Torr.) Kuntze. Stems erect: stipules linear: leaflets 2-5 

 em. long; blades linear or linear-oblong, reticulate, pubescent beneath: lateral 

 calyx-lobes deltoid, the markedly longer lower one triangular-lanceolate: 

 standard 5-6 mm. long: wings dilated near the tip: loment-joints obliquely 

 half -obovate, 3-3.5 mm. wide. — Lower Susquehanna valley. Bare, on the 

 river shore and islands. — Schists. 



5. M. canescens (L.) Kuntze. Stems erect: stipules ovate: leaflets 3-10 cm. 

 long; blades ovate to ovate-rhomboid: lateral calyx-lobes lanceolate, longer 

 than the tube, acute, the lower lobe longer and slender-tipped: standard 9-12 

 mm. long, narrowly obovate: androecium 9-11 mm. long: loment-joints half- 

 rhombic, 4.5-5.5 mm. wide. — Common, in fence-rows and thickets. 



6. M. bracteosa (L.) Kuntze. Stems erect: stipules lanceolate: leaflets 5-15 

 cm. long ; blades ovate to ovate-lanceolate, cuspidate or long-acuminate : 

 lateral calyx-lobes lanceolate, the lower lobe slightly longer: standard broadly 

 obovate, 8-10 mm. long: loment-joints half -rhombic, the one side somewhat 

 more prominent than the other. — S. Eather rare, in thickets. — Schists. 



7. M. paniculata (L.) Kuntze. Stems glabrous or nearly so: stipules subu- 

 late: leaflets 3-9 cm. long; blades mainly oblong to lanceolate, obtuse or 

 acutish: lateral calyx-lobes triangular, sometimes deltoid, acute, the lower lobe 

 decidedly longer and attenuate: standard cuneate or cuneate-obovate, 4.5-5.5 

 mm. long: keel-petals about as long as the standard: loment-joints 4-5 mm. 

 wide, the ventral side prominently rounded, the dorsal side curved. — Common, 

 in dry soil, often in woods. 



8. M. viridiflora (L.) Kuntze. Stems downy: stipules lanceolate: leaflets 

 4-9 cm. long; blades oblong to ovate or ovate-oblong, densely pubescent be- 

 neath: lateral calyx-lobes deltoid, shorter than the tube, the lower lobe 



