The Leaf 119 



one of these two venations, although there may be 

 differences in the courses the veins run and the amount 

 of branching they show. 



The leaves themselves vary so much in shape on 

 different trees that you can make a very interesting 

 collection by seeing how many different shapes of leaves 

 you can find. In the first place some leaves are all in 

 one piece or simple, while others are made up of a 

 number of leaflets, that is they are compound. Then 

 they show every gradation in shape from the needle- 

 shaped leaves of the pine to nearly round hazel leaves. 

 Leaves in between these two extremes may be lance- 

 shaped like the privet, oblong, or oval. Other leaves 

 again may be heart- or arrow-shaped. These names 

 will, however, mean nothing to you until you know the 

 leaves themselves and try to describe their shapes. 

 In order to give a clear word picture when a leaf is 

 being described the shape, venation, margin, and surface 

 should each be taken in turn. We have spoken of the 

 first two and will now pass on to the margin and 

 surface. 



A leafs margin is often quite smooth as in the 

 beech, when it is said to be entire. Other margins are 

 made up of tiny teeth like a saw, or they may be wavy 

 or lobed, or may cut the leaf blade up until the leaf is 

 nearly a compound one. The shape of some leaves, 

 which like those of the ash are drawn out into long 

 points called "drip tips," makes the rain drops run 

 quickly off the leaves, and some botanists think that the 

 trembling of an aspen leaf serves the purpose of shaking 

 off the rain. Be this as it may there is no doubt that 

 the surface of the blade usually shows some device to 

 ensure that water shall not remain there long, for 



