VOL. II.] 



MUSTARD FAMILY. 



135 



i. Leavenworthia uniflora (Michx.) Britton. 



(Fig. 1742.) 



Cardamine uniflora Michx. Fl. Bor. Am. 2: 29. 1803. 

 Leavenworthia Michauxii Torr. Ann. Lye. N. Y. 4: 89. 



1837- 

 L. uniflora Britton, Mem. Torr. Club, 5: 171. 1894. 



Tufted, 3 / -6 / high. Basal leaves rosulate, numerous, 

 i f -^ f long, the segments 5-17, irregularly dentate or 

 angled, 2 // -3 // long, the terminal one somewhat larger, 

 all narrowed near the base, but slightly expanded at 

 the junction with the rachis; stem-leaves none, or 1-3, 

 similar, but smaller; flowers about $" broad; petals 

 white or purplish with a yellow base, about twice the 

 length of the sepals; pods oblong or linear, 6 // -i5 // 

 long, 2 X/ wide when mature; seeds winged; style stout, 

 about */?." long. 



In open, dry places, southern Indiana to Tennessee, 

 west to Missouri. April. 



Michaux's Leavenworthia. 



2. Leavenworthia torulosa A. Gray. 

 Necklace I^eavenworthia. (Fig. 1743.) 



Leavenworthia torulosa A. 'Gray, Bot. Gaz. 5: 26. 1880. 



Closely resembles the preceding species, but the pods 

 are narrower and distinctly constricted between the 

 seeds. Style conspicuous, i^ // -2 // long; seeds 

 sharp-margined, barely winged; terminal segment of 

 the basal leaves decidedly broader and larger than the 

 lateral ones. 



Barrens of Kentucky and Tennessee. April. 



23. PHYSARIA A. Gray, Gen. 111. i: 162. 1848. 



Low perennial stellate canescent herbs, with erect or ascending usually quite simple 

 stems, spatulate mostly entire leaves, the basal ones tufted, and medium-sized yellow flowers 

 in terminal racemes. Petals longer than the sepals. Style filiform. Silicles membran- 

 ous., stellate-pubescent, their cells inflated, subglobose, the septum narrow. Seeds not mar- 

 gined; cotyledons accumbent. [Greek, bellows, from the resemblance of the inflated fruit.] 



About 4 species, natives of western North America. 



i. Physaria didymocarpa (Hook.) A. 

 Gray. Double Bladder-pod. (Fig. 1744.) 



Vesicaria didymocarpa Hook. Fl. Bor. Am. 1:49. PI- 



16. 1830. 

 Physaria didymocarpa A. Gray, Gen. 111. i: 162. 1848. 



Densely stellate-canesccnt, pale green; root long 

 and deep. Stems decumbent or ascending, slender, 

 simple, 3 / -i2 / long; leaves spatulate, the basal ones 

 obtuse, entire, or few-lobed, narrowed into mar- 

 gined petioles; terminal segment large, \'-$ f long; 

 stem-leaves nearly sessile, acute or subacute, much 

 smaller; racemes 2 / -5 / long in fruit; flowers 5 "-6" 

 broad; pods didymous, variable, often 6 r/ thick 

 through the strongly inflated cavities, emarginate 

 at base and summit, commonly broader than high; 

 seeds numerous. 



In dry soil, Northwest Territory to British Columbia, 

 Nebraska, Colorado and Nevada. May-Aug. 



