92 THE HUMAN SIDE OF PLANTS 



ground soon to germinate and spring into new 

 plants. 



Another kind of clinger is the cockle-bur. These 

 burrs also are covered with tiny sharp hooks, which 

 are terrible indeed when embedded in the skin of 

 animals, for they are almost impossible to shake 

 off or pick loose. These plants frequent pasture 

 lands and the burrs are especially prone to ride 

 on horses' tails. 



Still another clinger is the sand-spur, which grows 

 abundantly in open fields and in dry desert places 

 of America. The spurs are the seeds of a peculiar 

 form of sand-loving grass ; and when once they get 

 a start in a new region it is practically impossible 

 to free the land of them. These spurs attach 

 themselves to animals, and often lacerate their flesh ; 

 sometimes they so completely cover the feet of dogs, 

 or even of children, that it is impossible for them 

 to walk until the spurs are removed. Occasionally 

 the seeds fasten themselves in an animal's mouth, 

 causing it to suffer severe pain; they often attach 

 themselves to the beaks of doves and various prairie 

 birds. 



Every one has possibly seen the stick-tights 

 or has acted as their unwelcome beast of burden! 

 How harmless the little akenes (seed-pods) with 

 their tiny spiked horns appear! All the summer 



