The Leaf 125 



Although most ordinary leaves have a large blade 

 and a thin stalk with two small stipules at the end, each 

 of these parts may in some plants and trees look so 

 different that you would never recognise them. In the 

 pansy, for instance, the stipules have grown as large as 

 the blade. In some climbing plants the stipules have 

 turned into long curling tendrils, while in others the 

 blade has become a tendril and the stipules are large 

 enough to take its place. The position in which these 

 parts grow help to tell us what they really are, and 

 botanists find out more about them by comparing 

 plants belonging to the same family, or sometimes 

 by noticing the stages they go through in growing from 

 little seedlings to full grown plants. In the robinia 

 or false acacia two strong spines grow from the base of 

 each leaf. The place where they grow shows that they 

 are really stipules. They have turned into spines to 

 keep off any animals that want to feed on the tender 

 young shoots. One of the robinia's foreign cousins is 

 still better protected, for its stipule spines are large 

 and hollow, and are inhabited by a fierce kind of ant 

 which attacks any enemy that ventures too near. 



In the case of the gorse not only the stipules but 

 the very leaves themselves and the branches have 

 turned to spines. How do we know that all the spines 

 with which a gorse bush is covered are really leaves 

 and branches ? Well, in two ways. Firstly by noticing 

 the relative position of the spines and the buds or 

 flowers. The buds are borne in the axils of some spines 

 and upon others. Therefore some of the spines are 

 leaves and others branches. Secondly by looking at a 

 very young gorse seedling (Fig. 63). We see that at 

 first it is provided with soft leaves not unlike those 



