CRUCIFER/E. (MUSTAUD FAMILY.) 17 



eels glabrous. — D. muricdla, Walil. ? of Bot. Kiuf^'s Exp. 21; D. nivalis of 

 Ilaycl. Koj). 1S70. Uinta Mountains ami far nortliwartl. 



2. D. crassifolia, (Jrali. Scajje naked or with a single leaf, 1 to 3 

 inclies iiigli : leaces lanceolate-it near, entire or somewhat serrate, ciUate with 

 simple hairs: flowers small, i/ellow or white : pettils a little ixretdiuy the sipals, 

 retuse : pods ovate-cllii)tical, glabrous. — Alpine, frum Colorado noriliward, 

 and in California. 



3. D. alpina, L. Hather rigid : scape naked, mostly somewhat hirsute : 

 leaves spat ulatc-lanceol ate, more or less pilose with iranrhintj hairs: petals ijtllou', 

 more than twice the length of the sepals : pods somewiiat corymlted, obloug- 

 elliptical. — Aljjiiie, Colorado, Uintas, and northward to Arctic America. 



Var. glacialis, Dickie. Dwarf: leaves more rigid, linear or narrowly 

 ohlanceolate, more or less strongly carinate, stellate pubescent, not ciliate : jiods 

 short-ovate, pubescent. — D. glacialis of liayd. Kep. 1871, 1872. Teaks about 

 Yellowstone Lake and far northward. 



* * Stems leaf I/. 

 H- Flowers white. 



4. D. incana, L. Hoary jiubescent, seldom branching at the base : leaves 

 oblong-lanceolate, linear, or the lower spatulate: pods oblung-lanceolate, often 

 pubescent, on short erect pedicels. 



Var. eonf usa, Poir. Leaves sparingly toothed : pods pubescent. — M<jun- 

 tains of Colorado and in British America. 



5. D. euneifolia, Xutt. Hirsute-pubescent throughout with brnnching 

 liairs, usa(dly branching at base,-lesiiy below or only at base : leaves ohtnite or 

 spatulate with a narrow or cuneate /)a.s-p, sparingly toothed toward the apex: 

 pods linear-oblong, somewiiat pubescent with short ascending hairs, on spread- 

 ing pedicels. — Southern Colorado, eastward, and probably westward. 



•♦- H- Flowers yellow {white in one variety of "So. 7). 

 4-*- Pods glabrous {except in one variety of No. 7). 



6. D. Stenoloba, Ledeb. Sonieichaf villous with spreadinq hairs, glabrous 

 above: stems erect, with divergent or decuml)ent branches near the hnao : 

 leaves oblanceolate, rather tliin, rarely and sparingly toothed : tlie catiline few 

 and sessile : petals bright or pale yellow : pods linear, in nn elongated raceme 

 071 spreading scattered pedicels; style none. — D. nemnmsn, var. lutra,o{ Bot. 

 King's Exp. 22. Colorado mountains, the Uintas and Wa.satch, and we.<t- 

 ward to California. 



7. D. nGmorOSa, L. Leaves nblonq or somewhat lanrenfate, more or less 

 toothed : racemes elongated : petals emarginate, small : jwds elliptical -of Jong, 

 half the length of the horizonttd or widchi spreadinq pedicels. 



Var. leiocarpa, I.indb. Often with stem nearly or quite leafless, and 

 petals sonictiincs pinkish-white: sepals sparsely hirsute: p) dials scarcely e.r- 

 ceeding or even shorter than the qlabrous pods. — P. nen)()rn.<sa, var. luten, of 

 Fl. Colorado and Ilayd. Kep. 1871. Colorado and throughout Yellowstone 

 I'ark. 



Var. hebecarpa, Lindb. Pubescent : stem branched • pods puf>rscrnf, 

 one third the length of the pedicels. — D. nenwrosa of Bot. King's Exp. 22 and 

 Hayd. Rep. 1871. In the mountains from Colorado to Arctic America. 



