CRUCIFERAE. 



Vol. II. 



II. Draba nemorosa L. Wood Whitlow-grass. 

 Fig. 2007. 



Draba nemorosa L. Sp. PI. 643. 1753. 



Winter-annual, loosely stellate-pubescent, 6'-i2' high, 

 branching below, leafy to the inflorescence. Leaves 

 oblong-ovate, or lanceolate, obtuse, sessile, dentate, the 

 lower io"-i2" long, s"-?" wide, the upper smaller; 

 flowers yellow, fading to whitish, i" broad; petals 

 notched, slightly exceeding the calyx; pedicels divari- 

 cately spreading in fruit, glabrous, 3"-io" long; racemes 

 open, much elongating; pods pubescent, or glabrous, 

 oblong, obtuse, 3"-4" long; style none. 



Western Ontario, Michigan, Minnesota, South Dakota 

 and western Nebraska to Oregon, arctic America and south 

 in the Rocky Mountains to Colorado and Utah. Also in 

 northern Europe and Asia. Summer. 



12. Draba aurea Vahl. Golden Whitlow- 

 grass. Fig. 2008. 



D. aurea Vahl in Hornem. Fh OEcon. Ed. 2, 599. 1806. 



Perennial, pubescent throughout with stellate and 

 simple hairs ; stem branching or nearly simple, 6'-io' 

 high, leafy to the inflorescence. Basal leaves oblan- 

 eeolate or spatulate, 6"-i2" long, obtuse or acutish, 

 slightly dentate or entire, often ciliate at the base ; 

 stem-leaves oblong or lanceolate, acute; pods lanceo- 

 late or oblong-lanceolate, 4"-6" long; flowers yellow, 

 2" broad ; petals twice the length of the calyx, emar- 

 ginate or entire; pods acute, pubescent or rarely 

 glabrous, at length slightly twisted, 4"-7" long, on 

 erect pedicels one-half their length; style stout, 

 *" long. 



Mignon Island, Gulf of St. Lawrence to Labrador, 

 Greenland ; arctic America and in the Rocky Mountains 

 south to Arizona. Summer. 



13. Draba alpina L. Alpine Whitlow-grass. 

 Fig. 2009. 



Draba alpina L. Sp. Ph 642. 1753. 



Perennial by a branched caudex, densely tufted, 

 scapes pubescent, V-6' high. Leaves all basal, 

 entire or few-toothed, oblong, or oblong-lanceolate, 

 obtuse or acute at the apex, mostly narrowed at 

 the base, ciliate, or villous-pubescent, sometimes 

 with some stellate hairs, 2"-6" long, sessile or 

 short -petioled; flowers yellow, about 3" broad; 

 calyx pubescent or villous; style i" long or less; 

 pod oval or ovate, narrowed at both ends, glabrous, 

 or somewhat pubescent, 25"-4" long, i"-ii" wide; 

 pedicels ascending, i"-5" long 



Greenland to Hudson Bay, the mountains of British 

 Columbia and Alaska. Also in northern Europe and 

 Asia. Summer. 



Draba crassifolia Graham, a low annual or biennial 

 species, with tufted basal ciliate leaves, small yellowish 

 scapose flowers, of arctic and alpine distribution, ranges 

 south to Labrador. 



