284 



P/ants and their JVavs in Sont/i Africa 



by perianth leaves. Fruit a nut surrounded by an involucre, 

 the cup of the acorn and the burr of chestnuts. 



Pollination in the Oak occurs in September. At this time there are 

 no ovules in the three-chambered ovary to be fertilized. Soon, however, 

 two anatropous ovules appear in each chamber, only one ot which is 

 destined to become a seed ; and after fertilization which occurs early in 



P'lr;. 257. — Pn'U-it cviuunidc^, L., \\\\\\SliU!via i:^lii{ino^a , '\\\. (I'holograph 

 by E. J. Steer, Es<|.) 



Novemlier the other fi\'e disajipear, the one seed lillinj; the entire o\ary 

 which becomes tlie acorn. 



