CRUCIFERAE (MUSTARD FAMILY) 221 



ing; silique ovate to lanceolate or linear. Seeds in 2 rows, not winged or 

 margined. Pubescence simple or branched. 



Annuals or winter annuals. 



Silique glabrous; flowers yellow, sometimes turning white in 



drying. 

 Style wanting. 



Stems scapose, glabrous . . . . . . 1. D. crassifolia. 



Stems scapose, ciliate-hirsute below . . . . 2. D. nitida. 



Style evident . . . . . . . . 3. D. mongollonica. 



Silique pubescent; stigma sessile. 

 Flowers white. 



Leaves entire; siliques in a terminal cluster . . 4. D. caroliniana. 



Leaves toothed or entire; siliques in a somewhat elongated 

 raceme. 



Pedicels ascending or erect 5. D. cuneifolia. 



Pedicels reflexed 6. D. reflexa. 



Flowers yellow. 



Pedicels longer than the silique . . . . . . 7. D. nemorosa. 



Pedicels shorter than the silique . . . . . 8. D. lapilutea. 



Perennials. 



Low, caespitose, and scapose; leaves imbricated. 



Scape pubescent . . . . . . . . . 9. D. densifolia. 



Scape glabrate; silique ovate. 



Flowers white ......... 10. D. oligosperma. 



Flowers yellow. 



Silique broadly ovate . . . . . . . 11. D. andina. 



Silique ovate-oblong ....... 12. D. saximontana. 



Taller; stems more or less leafy. 



Siliques glabrous or nearly so, not twisted. 

 Flowers yellow. 



Pubescence branched; flowers large . . . 13. D. spectabilis. 



Pubescence simple; flowers small ..... 14. D. cnrysantha. 



Flowers white, small ........ 15. D. cana. 



Siliques pubescent, more or less twisted. 



Pubescence of herbage long and villous .... 16. D. streptocarpa. 



Pubescence of herbage short and stellate. 



Leaves large and thin ....... 17. D. surculifera. 



Leaves rather small and firm. 



Silique with flat valves, glabrate on the face . . 18. D. Helleriana. 

 Silique with convex valves, pubescent . . . 19. D. luteola. 



1. Draba crassifolia Graham, Edinb. New Phil. Journ. 1S2. 1829. Gla- 

 brous throughout or with the leaves sparsely ciliate, annual or biennial: scape 

 naked or with a single leaf, 5-10 cm. high: leaves lanceolate-linear, entire or 

 somewhat serrulate, ciliate with simple hairs: flowers small, white or yel- 

 lowish; petals a little exceeding the sepals, ret use: siliques oblong-lanceolate, 

 acute, 5-9 mm. long, on spreading pedicels of about the same length. (D. 

 Parri/i Rydb. Bull. Torr. Bot. Club 29: 241. 1902.) High mountains; Colo- 

 rado to British America. 



2. Draba nitida Greene, PI. Baker. 3: 7. 1901. Erect annual 1-3 dm. high, 

 glabrous and somewhat shining : stems 1 or more from the base, ciliate-pubescent 

 below only: leaves mostly in a rosulate tuft at the base, sparsely substel- 

 late, the margins loosely bristly-ciliate: raceme long in fruit: petals yellow, 

 longer than the green somewhat pilose sepals: silique oblong-linear, acutish, 

 10-15 mm. long, on ascending pedicels of about the same length. D. stenoloba. 

 At middle or higher elevations; Colorado to Montana. 



3. Draba mongollonica Greene, Bot. Gaz. 6: 157. 1882. Somewhat scapose 

 annual, 2-4 dm. high, villous or loosely stellate-pubescent below: stem simple 

 or branching from the base: leaves oblanceolate, stellate-pubescent, 3-6 cm. 

 long: flowers large, in broad racemes which are elongated in fruit: sepals 

 glabrous: siliques linear or oblong, glabrous, 8-15 mm. long, with a slender 

 style 2-3 mm. long; pedicels slender, variable, longer or snorter than the 

 silique. Infrequent; New Mexico and probably southern Colorado. 



4. Draba caroliniana micrantha Gray, Man. Ed. 5. 72. 1867. Low, usually 

 less than 1 dm. high: leaves obovate or oblanceolate, entire, rosulate or 

 crowded near the base, loosely stellate-pubescent, 10-12 mm. long: scapose 

 stems few or several from the crown, glabrous or pubescent: flowers small, 

 white, the pedicels closely approximate even in fruit: siliques minutely hispid, 

 10-15 mm. long, much exceeding the divergent pedicels. This variety does 



