There are leaves broader above than below, and some, instead of ending in a point, have a notch or indentation of some sort. Oak-trees give us many fine and varied samples of notched and lobed leaves. And yet the leaf of the chestnut-oak is not at all notched, being simply ovate, pointed, and toothed. The leaves of the bur and the pin oaks, on the contrary, are lobed and notched, and are therefore characteristic oak-leaves, while those of the chestnut-oak are not so, because almost all oaks have leaves more or less scalloped or deeply indented.
Great as is the variety in the shapes of oak leaves, any one of them would almost surely be at once recognized as belonging to an oak-tree by its peculiar scallopings. But suppose a person had never seen or heard of a chestnut-oak leaf, would he be likely to recognize such a leaf simply by its outline? There is still another oak with simple leaves; and they are not even toothed, but entirely smooth all around the edge. Looking at that tree, which is called the willow-oak, scarcely anyone would suppose it to be an oak unless he could see its flowers or its fruit, the acorns.
Chestnut-Oak Leaf.
Bur-Oak Leaf.
Pin-Oak Leaf.
This fact brings us to consider a very important point in the study of a plant. It is not the leaf which tells us what kind of plant it is: it is the flower and the fruit. Whatever be the shape of the leaf, if the plant bears acorns it is an oak. If a tree has cherries and cherry blossoms, it is a cherry.