70 



THE CRUCIFER FAMILY. 



dens, and sowing itself readily, it has 

 become more or less established as a 

 weed of cultivation in some parts of 

 England. Fl. all summer. Often dis- 

 tinguished as a genus, under the name of 

 Koniga. 



Fig. 86. 



XY. DRABA. DEABA. 



Small annuals or perennials, usually hairy or hoary with spreading 

 or tufted radical leaves, entire or toothed, the stem-leaves few or none. 

 Flowers white or yellow. Filaments of the stamens without appen- 

 dages. Pod oblong or elliptical, from one and a half to near three times 

 as long as broad, more or less flattened ; the partition broad ; the valves 

 flat or convex, their midrib usually distinct. Seeds several in each 

 cell. Padicle accumbent on the edge of the cotyledons. 



A considerable genus, ranging over the northern hemisphere, ascend- 

 ing to the greatest elevations and to high Arctic latitudes, and extend- 

 ing along the great mountain chain of America into the southern hemi- 

 sphere. The species mostly differ from Alyssum in their longer pod, 

 and in a peculiar habit approaching that of the Hockcresses ; from the 

 latter genus they are distinguished by the pod, which, though long for 

 a siliculose Crucifer, is still much shorter, in proportion to its width, 

 than in the shortest Roclccress. 



Flowers yellow (stiff tufted' perennial) 1. Yellow D. 



Flowers white. 



Biennials or perennials. Pedicels short and stiff. 



Stem with a few leaves, the radical ones spreading . . 3. Hoary D. 



Stem almost leafless, the radical leaves tufted .... 2. Rock D. 



