64 



TALKS AFIELD. 



sist of many soft hairs, as in the thistle, or 

 of barbed teeth, as in the beggar's 

 ticks (Fig. 54), or of minute teeth, 

 as in the coreopsis. In most cases 

 it is a means of distributing 

 the seed, either by floating it 

 in the air or by attaching it 

 to clothing or the coats of 

 Fig- 54- animals. In the dandelion 

 it is raised on a slender stalk. (Fig. 

 55.) The whole head in the com- ^ig. 55. 

 posite flowers is more or less surrounded by 

 little green leaves, like a 

 calyx. These leaves consti- 

 tute the involucre. The in- 

 volucre is shown at i in Fig. 

 56, and again in Fig. 57, 

 F^g- 56. where it is compact and 



tube -like and covered with 

 hooked bristles, making the 

 well-known bur of the burdock. 

 We are now familiar with 

 the essential structure of the 

 flowers of the Composite fam- 

 ily, — the aggregation into 

 heads, the pappus, the united 

 anthers, the gamopetalous co- Fig. 57. 

 rolla, the enlarged receptacle, the involucre, 



