EXPERIMENT STATION BULLETINS. 



433 



Fig. 246 (214). 



American Cocklebur. Xanthium cana- 

 densis Mill. A coarse, erect annual, 30-120 cm. 

 high; leaves broad, usually three-lobed; burs 

 nearly srr.ooth, 14-1" mm. long, 5-8 mm. in 

 diameter, beaks shghtly curved, priclvles 

 .scattered, slender, hooked. 



55 



Fig. 247. 



Common Cocklebur. Xanthium commune 

 Britton. Much like H. canadense beaks of bur 

 incurved, prickles numerous, crowded, 3-6 

 mm. long, hairy, as is also the body. 



