is 



NORTH AMERICAN FLORA 



[Volume 24 



Leaflets oblong, oblanceolate, or obovate; bracts as long as the 

 calyx or longer. 

 Bracts broadly ovate, enclosing the calyx. 3. 



Bracts lanceolate or linear-lanceolate, not enclosing the calyx. 

 Bracts ovate-lanceolate, acuminate, 10-15 mm. long, 



scarcely exceeding the calyx. 4. 



Bracts linear-lanceolate, caudate-attenuate, 15-20 mm. 

 long, much exceeding the calyx. 5. 



Plant with long spreading pubescence. 7. 



Stem very low (plant often subacaulescent), usually less than 1 dm. high, 

 sometimes with the lower branches elongate, 1-2 dm. long and pros- 

 trate. 

 Plant green, sparingly hirsute or strigose; leaflets oblong, oblanceolate, 

 or rarely obovate. 

 Upper 4 calyx-lobes very short, triangular, the lowest one obovate 



or spatulate; leaflets glabrous except the ciliate margins. 

 Upper 4 calyx-lobes subulate or lanceolate, 5 mm. long or more; leaf- 

 lets pubescent at least beneath. 

 Plant hirsute; lowest calyx-lobe slightly broader, but scarcely 

 longer than the rest; seeds smooth. 

 Plant usually with a distinct leafy stem; upper two calyx- 

 lobes united about half their length. 

 Plant subacaulescent ; stem above ground almost none ; upper 

 calyx-lobes distinct. 

 Plant appressed-strigose; lowest calyx-lobe much broader and 

 longer than the rest; seeds reticulate. 

 Peduncles much shorter than the petioles, scarcely longer than 

 the spikes; root oblong-fusiform; lowest calyx-lobe ovate- 

 lanceolate. 

 Peduncles often equaling the petioles, three to four times as 

 long as the spikes; root globose; lowest calyx-lobe narrowly 

 lanceolate. 

 Plant decidedly canescent ; leaflets broadly obovate. 



Lowest calyx-lobe not much larger than the rest; seeds smooth. 



Flowers distinctly pedicelled; pedicels 4-6 mm. long. 11. 



Flowers subsessile; pedicels 3 mm. long or less. 



Petioles with appressed pubescence; corolla nearly 2 cm. 



long. 12. 



Petioles with spreading or retrorse hairs. 



Corolla about 12 mm. long; leaflets cuneate -obovate. 13. 



Corolla about 17 mm. long; leaflets rounded-obovate, al- 

 most orbicular. 14- 

 Lowest calyx -lobe much larger than the rest; seeds reticulate. 



Lowest calyx-lobe rounded or obtuse at the apex, about 10 mm. 



long. 15. 



Lowest calyx-lobe acute at the apex, 12-15 mm. long. 16. 



Rachis produced beyond the lowest leaflets, bearing the terminal one at its 

 end; calyx and claw of the banner short. Subgenus Geomelum. 

 Leaflets 5; 4 sessile together and 1 on the produced rachis. 

 Leaflets 3 ; 2 sessile and 1 on the produced rachis. 



Plant caulescent; spikes few-flowered; corolla less than 1 cm. long 

 Petioles usually longer than the leaflets. 



Beak of the pod much longer than the body. 

 Beak of the pod scarcely longer than the body. 



Leaves and calyx densely canescent; lowest calyx-lobe not 



much longer than the rest. 1' 



Leaves and calyx glabrous or nearly so; lowest calyx-lobe 



much exceeding the rest. 



Petioles shorter than the leaflets. 21 



Plant acaulescent; spikes many -flowered; corolla 15 mm. long or more. 22 



P. Rcverchoni. p>> 



P. cuspidatum. 



P. caudalum. 

 P. esculentum. 



6. P. subacaule. 



P. esculentum. 

 P. subulatum. 



9. P. hypogaeum. 



10. 



P. scaposum. 



P. californicum. 



P. megalanlhum. 

 P. mepkiticum. 

 P. relrorsum. ~~ 



P. castoreum. 

 P. trinervalum. 



17. P. penlaphyllum. - 



18. P. rhombifolium. 



20. 



P. oliganthum. 

 P. brachypus. 

 P. humxle. 



1. Pediomelum canescens (Michx.) Rydberg. 



Psoralea canescens Michx. Fl. Bor. Am. 2: 57. 1803. 

 Lolodes canescens Kuntze, Rev. Gen. 194. 1891. 



A perennial, with a subglobose or fusiform tuberous root sometimes 4 mm. thick; stem 

 3-10 dm. high, coarsely canescent, much branched; leaves digitately 1-3-foliolate, subsessile 

 or short-petioled; petioles 8 mm. long or less; stipules lanceolate or subulate, 1 cm. long or less; 

 leaflets rounded-obovate, narrowed into distinct petiolules, 2-5 cm. long, rounded at the apex, 

 minutely glandular-punctate and glabrate above, villous-canescent beneath; peduncles 2-5 

 cm. long; spikes loose, short, 2-4 cm. long; bracts 4-6 mm. long, ovate-acuminate; flowers short- 

 pedicelled; calyx sparingly pubescent, 7 mm. long; lobes broadly lanceolate, acuminate, the 

 upper four nearly 4 mm. long, the lowest about 7 mm. long; corolla dark-blue, 10-12 mm. long; 



