CHAPTER XXIV 



DISPERSAL OF SEEDS 



327. It is to the advantage of the plant to have its seeds 

 distributed as widely as possible. It has a better chance of 

 surviving in the struggle for existence. 

 4 jJ 4 t/ ^ ets away fr m com Petition. Many 



v! >^JL seeds and fruits are of such 



character as to increase 

 their chances of wide dis- 

 jjf*^ persal. The commonest 



W } \r means of dissemination may 



/ be classed under four heads: 



explosive fruits; transporta- 

 tion by wind; transporta- 

 tion by birds; transportation 

 as burs. 



328. Explosive Fruits. 



Some pods open with explosive force and scatter 

 the seeds. Even beans and everlasting peas 

 (Fig. 272) do this. More 

 marked examples are the 

 locust, witch hazel, gar- 

 den balsam, wild jewel- 

 weed or impatiens 

 (known also as ' 'touch- 

 me-not"); violet, and the oxalis. (Fig. 

 300.) The oxalis is common in several 

 species in the wild and in cultivation. 

 One of them is known as wood sorrel. 

 Fig. 300 shows the common yellow 

 (166) 



300. Explosive fruits of 

 oxalis. An exploding 

 pod is shown at c. The 

 dehiscence is shown at 

 b. The structure of the 

 pod is seen at a. 



301. 



Winged seeds of 

 catalpa. 



302. 



Wind-blown fruits 

 of dandelion. 



