CHAPTER XI 



PLANT DEFENCES ' 



Silver leaves are favourite souvenirs for strangers who visit 

 our shores. The stranger finds that the Silver Trees which 

 wave their welcome from Table Mountain are but the harbingers 

 of many surprises that await him in the plant world. The 

 climate of South Africa is different from that of any other 

 country, and so plants look and behave differently. 



In many parts of this country plants have to do their work 

 principally in winter, as the summers are too hot and dry. In 

 the east and north winters are cool and dry, and plants have 

 a warm summer with rains in which to do their work. In 

 other parts it rains neither summer nor winter for months — 

 even years ; and to tide plants over these seasons of drought 

 innumerable devices are found. 



In cold countries of the northern hemisphere, winter is the 

 sleeping-time of plants. When the leaves are cut off in the 

 " fall " of the year, they lie in sodden heaps beneath the trees 

 during the autumn rains and winter snows. In the spring these 

 leaves hold moisture and give it up slowly to the roots. In 

 this country very little decaying vegetation is left on the 

 ground. The ants could partly explain the reason if you 

 asked them. Have you ever watched them before a rain 

 busily sawing off twigs and carrying them under ground? 

 Even burnt matches are regarded valuable timber by them. 

 The ants change the conditions for plants both above and 

 below the soil surface. 



Plants that work in winter must be suitably clothed for 

 their work. Even when no rain falls, the Silver Trees on Table 

 Mountain are frequently enfolded by the fringes of the " Table 



