DESCRIPTIVE MANUAL 291 



Extermination. — Botli of the jimson weeds are easily destroyed 

 by cultivation. They produce an enormous amount of seed which 

 probably retains its vitality for a considerable length of time. How 

 long, however, has not been determined. 



SCROPHU'LARIACEAE, MULLEIN FAMILY. 

 Snapdragon and Simpson honey plant belong to this family. 



Mullein {Verhascwm thapsus L.). 



Description. — A tall, densely woolly annual or biennial herb 2-6 

 ft. high; leaves oblong, thick, covered with branched hairs, the 

 basal leaves margined, petioled; flowers in long dense spikes; coroUa 



l^'ig. 167. Mullein (Verbascum thapsus). A hairy biennial, common road- 

 side weed ; gravel hills along Mississippi river, old fields. 

 (Photographed by Colbum.) 



