54 CRUCIFER^. [Draba. 



m 



15. Z). crassifolia; scapo nudo vel unifoliato, pedicellis calyceque glaberrimis, foliis 

 lineari-spathulatis subcarnosis, pilis simplicibus ciliatis, petalis apice retusis calycem paulo 

 superantibus. — Graham in Edin, PhiL Joum, 1829. p. 182. 



«, petalis albis. 



/8. petalis pallide flavis. 



Madix parva, gracilis, descendens, fibrosa, supcrne multiceps. Folia rosulataj fere onmino radicalia, vix 

 unciam longa, lineari-spathulata, subcamosa, pallide viridia, integerrima vel paucidentata, glabra, margine 

 pilis simplicibus albis ciliata, basi nou raro iu petiolum longiusculum attenuata, Scapi 2, 3, noununquam 

 4 imcias longi, flexuosi vel curvati, aphylli, vel folium unicum lineare basia versus gereutes, glaberrirai. 

 Flores laxe corymbosi, pauciflori, Pedicelli subcurvati vel flexuosij demura patcntissimi. Calycis scpala 

 ovato-rotuudata, glaberrimaj viiidia ad marginem pallidiora. Petala alba, iu /3. pallide fiava, obovata, basi 

 attenuata, apice retusa vel obtusisslme emargiuata. Siliculce glaberrimse, elliptico-ovata. Stigma sessile, 

 parvum. 



Hab. Summits of tbe Rocky Mountaius, between lat. 52° and 57°. — The small size of the whole 

 plant, frequently not rising more than 2 inches above the surface of the soil, the absence of pubescence, its 

 waving scapes and pedicels, and small flowers, would seem to constitute a distinct character ; yet the larger 

 specimens offer many points in common with the D. glabella. Pk, The general habit is that of Erophila 

 vulgaris^ but its petals are by uo means bipartite, but simply notched. 



# # 



Caulis foliosus. Annuw vel Biennes. 



16. Z). ? l(Bvigata ; caulibus foliosis simplicibus glabris strictis, foliis radicalibus et 

 caulinis inferioribus petiolatis ovatis basi attenuatis carnosiusculis margine obsolete ciliatis, 

 siliculis oblongo-lanceolatis, pedicellis brevibus quadruple sextuplo longioribus glabris. — 

 Cham, et Schlecht in LinncBa, v, 1. p. 25. 



Hab. Island of St. Lawrence. C/iamisso, — Of this plant, with which I am wholly unacquainted, Chamisso 

 and Schlechtendal say that it has a very peculiar habit in the absence of the radical tufts of leaves, the simple 

 stem, and in its smoothness and fleshiness. 



17. D. glabella; foliis radicalibus oblongo-spathulatis, caulinis 2-4. ovatis dentatis vel 

 integris, omnibus caule pedicellisque leeviter substellato-pubescentibus, petalis (albis) calyce 

 glaberrimo plusquam duplo longioribus, siliculis — ? — Pursh, FL Am, v, 2. p. 434 ? Mich, 

 in FrankL \st Journ, ed. 2. p, 27. 



Hab. Margins of alpine rivulets in the Rocky Mountains, between lat. 52° and 57°. Drummond; and 

 north in the plains. Dr. Hichardson. Hudson's Bay. Pursh. — This has more the habit of Z). crassifolia 

 than of the following ; but it is three or four times the size, and has flowers as large as any in the genus. 

 The siliculie I have not seen. 



18. D. confusa; caule folioso subramoso pube stellata brevi velutino, foliis oblongis 

 subdentatis, siliculis oblongis pubescentibus pedicello longioribus. DC, — ^^ Ehrh. Beitr* 7. 

 p. 155." De Cand. Prodr, v. I. p. 170. 



Hab. Rocky Mountains, from lat. 52° ; and north in the plains, nearly to the mouth 0f the Mackenzie 

 River. Drummond. Richardson. — This too is a very variable plant, in respect to the number of leaves on its 

 stem, their shape and margin, (entire or toothed,) and the pubescence of the whole plant. It insensibly 

 passes into the following species. 



19. D, incana ; caule folioso simplici vel ramoso pube stellata velutino, foliis ovatis 

 dentatis, siliculis oblongis glabris vel pubescentibus contortis vel strictis. 



