218 CRUCIFERAE (MUSTARD FAMILY) 



pubescence intermingled with the long-rayed stellate canescence: fruits very 

 large, thin, and papery. Powder river, Wyoming. 



2. Physaria vitulifera Rydb. Bull. Torr. Bot. Club 28: 278. 1891. Re- 

 sembling the foregoing, but leaves less whitened, fiddle-form in outline: peti- 

 oles somewhat margined and bearing a very few large teeth; stem leaves en- 

 tire, oblanceolate: silique deeply divided above only, the cells round-obovate, 

 divergent; pedicels more or less curved in fruit. Dry ravines and canons; 

 Colorado. 



3. Physaria floribunda Rydb. 1. c. Densely tufted, the numerous stems 

 and leaves suberect, 15-25 cm. high: radical leaves oblanceolate or spatulate, 

 sinuately toothed, usually acute, 5-10 cm. long; cauline oblanceolate, entire: 

 petals bright yellow, oblanceolate, with a broad claw, 8-9 mm. long, twice 

 as long as the lanceolate sepals : silique deeply divided above only, the cells 

 globose, 6-8 mm. in diameter. (P. acutifolia Rydb. 1. c.) Colorado and 

 Utah. 



4. Physaria Newberryi Gray, Bot. Ives Rep. 6. 1860. White, with the 

 dense fine stellate pubescence: leaves and stems rosulate spreading: leaves 

 mostly entire, petioled; radical orbicular to spatulate; cauline spatulate to 

 nearly linear: flowers large; petals 12-15 mm. long: silique deeply notched 

 above, scarcely notched at all below ; the cells laterally flattened and provided 

 with two keels or ridges separating the convex dorsal surface from the nearly 

 flat sides, the walls folding along the keels in drying. Colorado and New 

 Mexico to Utah and Arizona. 



15. LESQUERELLA Wats. BLADDER POD 



Low densely stellate-canescent herbaceous annuals, biennials, or perennials 

 (sometimes with frutescent base), with more or less rosulate radical leaves, 

 and yellow flowers in elongated or corymbose racemes. Sepals equal at 

 base, oblong. Petals spatulate or oblong-ovate. Siliques turgid, oblong- 

 ovate, or globose; style slender, rather long, persistent. Seeds flattened. 

 Vesicaria. 



Siliques stellate-pubescent. 



Globose or nearly so, not compressed at apex. 



All the leaves narrow (linear or oblanceolate) . . . .1. L. argentea. 



Some of the radical leaves broad (oval or obovate). 



Silique and pedicel subequal; the style shorter . . 2. L. macrocarpa. 



Silique and style subequal; the pedicel longer . ... 3. L. prostrata. 



Ovate or oblong, often compressed at apex. 

 All the leaves narrow (linear or oblanceolate). 

 Plants low, caespitose (less than 1 dm. high). 



Raceme' and leaves subequal . . . . . 4. L. condensata. 



Raceme surpassing the leaves . . . . . 5. L. alpina. 



Plants taller, not caespitose, branched from the base (more 



than 1 dm. high) . . . . . . 6. L. curvipes. 



Some of the radical leaves broad (orbicular to obovate). 



Raceme elongated, narrow . . . . . 7. L. montana. 



Raceme short, subcorymbose . . . . . . 8. L. valida. 



Siliques glabrous. 



All leaves narrow (linear or oblanceolate) . . . . 9. L. Fendleri. 



Some leaves broad (orbicular to obovate). 



Stem leaves linear to oblanceolate ...... 10. L. Engelmannii. 



Stem leaves large, thin, elliptic 11. L. aurea. 



1. Lesquerella argentea (Pursh) MacM. Met. Minn. 263. 1892. Stellate- 

 pubescent throughout but greenish rather than white: stems several from the 

 crown, decumbent spreading, simple or branched: leaves all linear or linear- 

 oblanceolate ; the basal crowded-rosulate, 3-8 cm. long, entire or remotely 

 toothed: raceme in fruit 10-25 cm. long: silique globose or nearly so, about 

 5 mm. long, equaling the slender style: pedicel spreading or recurved, 1-2 cm. 

 long. Vesicaria ludoviciana. Colorado to Montana and Minnesota. 



2. Lesquerella macrocarpa A. Nels. Bot. Gaz. 34: 366. 1902. Light green 

 but stellate-pubescent throughout, freely branched from the crown ; branches 

 decumbent-prostrate with assurgent tips, mostly simple: radical leaves or- 

 bicular to obovate, short-petioled; cauline oblong or oblanceolate, short- 



