/ CRUCiFERAE (MUSTARD FAMILY) 22 1 



ingjJsilique bvate to lanceolate or linear. Seeds in 2 rdws, not winged or 

 margined. Pubescence siinple pr branched. ' 



Aiwuala or winter annuajs, 

 SiUque glabrous; flowers yellow, sometimes, turning white i& 

 drying. 

 Style wanting. ' -r. .» ,. ' 



Stems scapose, glabrous . . . . . . . 1. ,]>. crassifolia. 



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



Style evident ' 3, D. mongollonicai 



Silique pubescent; stigma sessile. r.' ! ^ 



Flowers white. ■ . ! 



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

 Li^Ves toothed or entire; siliques in a somewhat elbilgated 

 raceme. ■ : . , , . » ■ !■ ; 



Pedicels ascending or erect . ,, .. . . . . S. D. cuneifolia. 



Pedicels reflexed . . ... . . .6. D. reflexa. 



Flowers yellow. '■■'■::• 



Pedicels longer than the siliiiue .;..,. 7. D. nemorosa. 



Pedicels shorter than the silique 8, D. lapili^tea. 



Perennials. 

 Low, caespitose, and scapose; leaves imbricated. 



Scape pubescent . . , 0. D. densifolia. 



Scape glabrate; silique ovate. 



Flowers white ... 10. D. oligosperma. 



Flowers yellow. 



.' -Silique broadly ovate -j, • • • • • .11. D. andina. 



Silique oyate-oblong 12. D. saximontana. 



Taller; stems more or less leafy. 

 ~ Siliques glabroils or nearly so, not twisted. 



Flowers yellow. ., :i '. ■ 



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 qf herbage .long and villous .... 16. D, streptocarpa. 



Pubescence of herbage short and stellate. 



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



Leaves rather small and Arm. 



Silique with flat valves, glabrate on the face . . IS'.-D.-Helleriana. ..^ 

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



1. Draba crassifolia Graham, Edinb. New Phil. Jouj-n. 182: 1829. Gla- 

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

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

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

 lowish j petals a htt;le exceeding the sepals, retuse: siliques oblong-lanceolate, 

 acUte, 5-9 mm. long, on spreading pedicels of about the saiiie length. {D. 

 Parryi Rydb. Bull. Torr. Bot. Club 29: 241. 1902.')— High mountains; Colo- 

 rado to British America. 



2. Draba nitida Greenej PL Baker. 3:'7. 1901. Erect annual 1-3 dm. high, 

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

 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 thaii the green somewhat pilose sepals: silique oblong-lmear, 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 motigollonica Greene, Bot. Gaz. 6: 157. 1882. Somewhat scaposje 

 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 Unear or oblong, ^abrous, 8-15 mm. long, with a glend0r 

 style 2-3 mm. long; JJedicels slender, variable, longer or shorter than the 

 silique. — ^Infrequent; New Mexico and probably Southern Colorado. 



4. Draba caroliniana tnicrantha Gray, Man. Ed. 5. 72. 1867. l^ow, usually 

 less than 1 dm. high: leaves obpvate or oblanceolate, entire,' rosulate pr 

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

 stems few or several from the crown, ^abrpus 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 



