LESSONS WITH PLANTS 



335 



umber of small flowers closely grouped together in a flat 

 ead. On account of this structure the head is called a 

 omposite flower. This grouping is a device to make more 

 f a show than if the little flowers were scattered separately 



Fig. 134. 



A section of a sunflower showing involucre bracts, rayfloweis, and small tubular flowers standing 

 on the flat receptacle. The central flowers are still closed. Then come several showing stamens, 

 and the outer ones have gone to seed. 



ver the plants. Thus insects are more apt to be drawn to 

 tiem. 

 The above named composites have two sorts of flowers, 

 he ray flowers at the margin and a centre of tubular flowers. 

 iut there are modifications of this type. Some composites, 

 ke the dandelion and double aster, chrysanthemum, daisy, 

 nd zinnia, have only strap-shaped flowers throughout the 



