104 CRUCIFER^. Dhaba. 



Melville Island ! Shore of the Arctic Sea ! Kotzebue's Sound.— Flowers 

 lar2:e, fine yellow, rarely white. Our specimens from Melville Island have 

 the scape and sepals nearly glabrous, and the leaves very sparingly hirsute. 



3. D.glaciaUs (Adams): scape naked, stellately pubescent or glabrous; 

 leaves linear-lanceolate, entire, rigid, stellately pubescent; petals (yellow) 

 twice the length of the calyx ; silicles racemose, oblong-ovate, the ceUs 5-6- 

 seeded ; style short. — '"'' Adams, in merii. soc. iiat. Mosc." ex DC. j)rodr. 1. p. 

 167 ; Hook. ! fl. Bor.-Am. 1. p. 51. 



a. scapes, pedicles, and silicles [nearly] glabrous ; flowers pale yellow. 

 Hook. ! I. c. 



/?. scapes and pedicels pubescent ; silicles glabrous. Hook. ! I. c. 



y. scapes, pedicels, and silicles strongly hirsute-pubescent. Hook. ! I. c. 



S. smaller ; scapes numerous and, with the pedicels, glabrous ; flowers very- 

 pale yellow. Hook..' I.e. 



e. smaller ; scapes and pedicels glabrous ; flowers deep yellow. Hook. I. c. 



Rocks on the loftiest of the Rocky Mountains, lat. 52^-57°, and on the 

 shores of the Arctic Sea. — Leaves narrow and more rigid than in the pre- 

 ceding species, furnished with a strong midrib. Style short, but distinct. 



4. D. oligosperma (Hook.) : scape naked, slightly pubescent ; leaves 

 erect, linear, rigid, ciliate, stellately pubescent on both sides, especially 

 towards the apex ; petals (white) twice as long as the slightly hairy calyx ; 

 siUcles pubescent, racemose, elliptical, rather acute at each end, 4-8-seeded, 

 four times the length of the style. Hook. ! Jl. Bor.-Am. 1. p. 51. 



fi.1 Andina (Nutt. ! mss.) : " densely csespitose; leaves imbricated, linear- 

 oblong ; silicle ovate, rather obtuse at the base ; cells about 2-seeded." 



Mackenzie's River, lat. 68^. P. Summits of lofty hills towards the sources 

 of the Platte, within the Rocky Mountain range. Nuttall ! — Stems or scapes 

 in a. 3 inches ; in /?. 2 inches high. Leaves about 3 lines long. Pedicels a 

 little longer than the fruit.— The var. /?. diff"ers in its more densely imbricated 

 leaves, as well as in the shorter and fewer-seeded silicles. The flowers have 

 not been seen. It wiU perhaps prove to be a distinct species. 



5. D. densifolia (Nutt. ! mss.) : " densely csespitose in somewhat globose 

 tufts ; leaves closely imbricated, oblong-linear, strongly ciliate, and hirsute 

 with nearly simple hairs ; scapes naked, hirsute ; silicle ovate, pubescent, 

 with a style about one-third its length; cells mostly 2-seeded. 



" On the central chain of the Rocky Mountains towards Lewis's River. — 

 Resembles the preceding, but differs in the pubescence being nearly simple, 

 and in the remarkable density of the fohage." Ntdt. 



6. D. pauciflora (R. Brown) : scapes and pedicels hairy ; leaves lanceo- 

 late, entire, hairy (the hairs simple or branched) ; petals (yellow) spatulate, 

 scarcely exceeding the hirsute calyx. B. Br. in Parrifs 1st voy. app. p. 

 266 ; Hook. Jl. Bor.-Am. 1. p. 51. 



Melville Island. — A doubtful species : near D. alpina. /?. Brown. 



7. D. micropetala (Hook.) : scapes and pedicels hairy ; leaves broadly 

 lanceolate, veiny, entire, covered with a simple or branched pubescence ; pe- 

 tals (white) linear-spatulate, scarcely exceeding the slightly hairy calyx; si- 

 licles eUiptical, glabrous ; stigma sessile, emarginate. Hook. ! in Par-ry''s 2d 

 voy. app. p. 385, (fjl. Bor.-Am. 1. p. 52. 



island of Igloolik, and (/?. minor) sea coast of Arctic America. — Habit of 

 D. alpina. The flowers resemble those of D. pauciflora, but are white. 



8. D. mxiricella (Wahl): scape naked, velvety; leaves oblong, entire, 

 canescent with u soft stellate pubescence ; silicles oblong-lanceolate, gla- 

 brous (flowers white.) DC— Wahl. jl. Lapp. p. 178. t. 11. /. 2; DC. 

 prodr. 1. p. 168 ; Hook.Jl. Bor.-Am. 1. p. 52. D. nivalis, Liljeblab.; Pursh, 

 Jl. 2. p. 433 % 



