OP ARTS AND SCIENCES. 257 



peduncles very short ; fruiting raceme about an inch long and with the 

 pod sparsely pubescent: flowers small, white, the petals scarcely longer 



8. D. (?) asprella, Greene. Pubescent with spreading simple or forked 

 hairs; scape-like peduncles one to several : filaments dilated downward: pods 

 oblong-elliptical, somewhat turgid, hispid, on divaricate pedicels ; style slender. 

 — Torr. Bull. 9. 125. Arizona. A doubtful species by reason of the turgid pod 

 and dilated filaments. Mature fruit has not been seen. 



* * High mountain or northern species: leaves entire or few-toothed : flowers 

 small, yellow, becoming whitish : stigma sessile. 



9. D. nemorosa, Linn. Usually branching below, loosely stellate-pubescent: 

 leaves rarely rosulate, ovate to oblong-lanceolate : racemes nearly sessile : pods 

 narrowly oblong, or oblong-elliptical, acutish, minutely pubescent (rarely gla- 

 brous, var. leiocarpa, Lindbl.), 3 or 4 lines long; pedicels spreading or divaricate, 

 6 to 12 lines long. — From the Great Lakes across the continent to Oregon, and 

 northward. Europe and Siberia. 



10. D. stenoloba, Ledeb. Simple or branching below, villous toward the 

 base : leaves mostly subrosulate, oblong-obovate or oblanceolate, the 1 or 2 

 cauline ovate to oblong-lanceolate, mostly entire, usually more or less villous 

 and ciliate : pods linear, acute, glabrous, 4 to 7 lines long, equalling or exceed- 

 ing the spreading pedicels. — Subalpine, from Colorado to the Sierra Nevada 

 and northward ; Unalaska. 



11. D. Montana, Watson. Stellate-pubescent throughout and somewhat vil- 

 lous, leafy : racemes nearly sessile : pods linear-oblong, finely pubescent, obtuse 

 or acutish, longer than the erect or ascending pedicels. — Proc. Am. Acad. 14. 

 289. Northern Colorado. 



12. D. crassifolia, Graham. Annual or biennial (?), very slender, glabrous 

 throughout or the leaves ciliate : leaves in a basal tuft, narrowly oblanceolate : 

 peduncles scape-like : pods lanceolate or oblong-lanceolate, acute, equalling or 

 exceeding the spreading pedicels. — Colorado and northward, and in the Sierra 

 Nevada; Greenland. 



§ 4. Drab.ea, Lindl. Perennial caulescent or scapose above the branching 

 leafy-tufted caudex (sometimes biennial and simple-stemmed in species of 

 * * •<- -i- ) : leaves flat, soft, more or less broad, not carinate. 



* Scapose. 



i- Flowers yellow : leaves entire (less than 6 lines long). 



13. D. alpina, Linn. Caudex much branched, densely cespitose : leaves 

 oblong-oblanceolate, with thick mid vein at base, glabrous and villous-ciliate or 

 somewhat villous-pubescent with simple or stellate hairs : scape pubescent : 

 calyx villous : pods usually glabrous, ovate to oblong-ovate, acute ; style short ; 

 stigma broad. — D. paucijiora, R. Br. D. micropetala, Hook. Greenland; Arctic 

 coast and islands ; Hudson's Bay; Rocky Mountains (Drummond ; D. rupestris, 

 £, Hook. Fl. Bor.-Am.). Northern Europe; Siberia. 



14. D. Howellii, Watson. Cespitose, finely stellate-pubescent throughout : 

 leaves broadly spatulate : flowers large, deep yellow : pods pubescent, some- 

 what obliquely oblong, acute at each end, on spreading pedicels ; style slender. 

 — Proc. Am. Acad. 20. 354. Siskiyou Mountains, California {Howell). 



VOL. XXIII. (n. s xv.) 17 



