52 



FIG. 21. 



HOUND'S TONGUE, DOG BUR, OR BURS. 

 Cynoglossum officinale. 



A biennial weed, with erect hairy stem, of rank growth, and much 

 branched, one to three feet high. The lower leaves have petioles ; the 

 upper ones clasp the stem. They are 6-12 inches long and covered with 

 downy hair, and have a disagreeable odour resembling that of mice. 

 The flowers are small and lurid purple-red in color. The fruit consists 

 of a broad, rounded bur, J inch long, with one flat side and covered with 

 short spines which enable it to adhere to clothing or to animals (Fig. 21 , 

 a). An average plant produces about 600 seeds. 



Time of flowering, June-August. 



Time of seeding, July-September. 



Dispersal chiefly by animals carrying the burs. 



Eradication. Spud or cut deep in fall and early spring ; the former 

 to destroy the plant in its first year, and the latter to complete the 

 destruction by removing those that escape the first cutting. 



