SEED-BEARING PLANTS 



483 



believed to be derived. The method of pollination in 

 normal flowers is illustrated in Fig. 370. 



424. Composite Family (Composite). The composites 

 represent the highest development of dicotyledons. The 

 flowers are borne on a common receptacle in a compact 



n 



FIG. 367. Sections of flowers of the toad-flax (Linaria vulgar is). 

 A, front view; a, anthers; s, stigma; n, nectar-gland. B, side view; 0, 

 ovary. 



"head," giving the appearance, not so much of an in- 

 florescence as of a compound flower, whence the family 

 name, assigned by early botanists, who did not understand 

 the morphology of the head. 



The heads are surrounded by a circle of bracts, called 

 an involucre. The bracts which often occur on the re- 



