190 



ELEMENTS OF BOTANY. 



The usefulness of burs to the plant which produces them is 

 evident enough. 



I II 111 



Fig. 176. —Dehiscent Fruits. 



I, linear capsule of celandine ; II, pod of pea ; III, capsule of thorn-apple 



or Jamestown weed. 



Pig. 177. — Adhesive Fruits. 

 At left, hound's-tongue ; at right, cleavers. 



Why do bur-bearing plants often carry their fruit until 

 late winter or early spring? 



