THE LEAVES 



81 



way. But not always ; for we do not know enough of 

 the kind of Hfe that the tree had to hve when, in the 

 old days, it was finding out the kind of leaf that would 

 suit it best. The umbrella tree throws up a very high 

 bare stem and an umbrella-shaped crown of leaves on 

 the top. When placed by itself on a lawn, there 

 seems to be a great waste of bare stem ; but when we 

 see the tree in the dense forest of Queensland where 

 it is native, we understand how beautifully it is adapted 

 to its home. And so with a hundred other trees that 

 have been taken from their native haunts and placed 

 in our gardens.* 



9. Sometimes we get a clue to the meaning of leaf- 

 shapes and leaf habits in watching how plants change 

 the shape and position of the leaf as they grow older. 



10. Plants that alter 

 their leaves as they 

 grov^^ older. You must 

 have noticed that a 

 young gum-tree often 

 has round or oval leaves, 

 while the same tree later 

 on has long narrow 

 leaves. In the young 

 blue-gum the leaves are 

 opposite, while on the 

 old tree the leaves hang 

 singly (fig. 57). The 

 young leaf, too, often 

 holds its face to the sky, 

 while the older leaf 



Fifr 57 



Young and. old leaves of gum-ti-ee. 



* The way in which leaves are folded in the bud helps to determine 

 shape ; but this is a study for senior students. 



