CHAPTER XXII 



oxalis. An exploding 

 pod is shown at c. The 

 dehiscence is shown at 

 6. The structure of the 

 pod is seen at a. 



DISPERSAL OF SEEDS 



300. It is to the plant's advantage to have its seeds 

 distributed as widely as possible. It has a better chance 



a of surviving in the struggle for exis- 

 tence. It gets away from competition. 

 Many seeds and fruits are of such 

 character as to increase 

 their chances of wide dis- 

 persal. The commonest 

 means of dissemination 

 may be classed under four 



273. Explosive fruits, of heads: explosive fruits ; 



transportation by wind ; 

 transportation by birds ; 

 burs 



301. EXPLOSIVE FRUITS. Some pods 

 open with explosive force and scatter the 

 seeds. Even beans and everlasting peas (Fig. 



246) do this. More marked 



examples are the locust, 



witch hazel, garden balsam, 



wild jewel weed or impa- 



tiens, violet, and the oxalis 



(Fig. 273). The oxalis is 274. winged seeds 



common in several species 



in the wild and in cultivation. One 



of them is known as wood -sorrel. 



Fig. 273 shows the common yellow 



oxalis. The pod opens loculicidally. 



(158) 



275. 



Wind-blown fruits 

 of dandelion. 



