like a canoe. It is bright green above and silvery underneath. The leaf of the white willow is a gray green lined with silver, and it droops from yellow stems. The crack willow, whose twigs snap so easily, has a green leaf lined with a waxy coating. The weeping willow has long, sad, gray "weeping" leaves.
The leaves of the alders are darker and broader than those of the willows, and the undersides are hairy. The poplars all have broad, heart-shaped leaves of emerald green satin, many of them silvery underneath. They are always in motion, so they shimmer in the sun in quite a dazzling way. The tall, slim, Lombardy poplars seem robed in dark green, flowing satin.
After the maples and willows, very likely you know oak trees best. The oak leaf is very irregularly shaped, like the oak tree. It is a long, oval or pear-shaped leaf, usually narrowest at the stem end, and is deeply notched and lobed. It is a strong, tough leaf as glossy above as if varnished, and rough underneath, with woody veins standing out like a net-work of cords. The scarlet, the red and the black oaks have about five, sharply notched lobes with broad partings, and each lobe is often notched again. The white oak has seven or nine narrow, rounded lobes, with very deep rounded partings cut down almost to the midrib. The bur oak has five or seven broad round lobes and narrow partings. In the swamp oak the leaf is deeply and irregularly scalloped. The chestnut oak leaf is oval with shallow scallops, and the smaller live oak leaf has wavy edges.
The oaks ring all the changes from many sharp, almost spine-tipped lobes to wavy edges. And they are very puzzling, for they are not all alike even on one tree, nor in different seasons. The best way to be sure of an oak tree is to study the acorns. Oaks can be as tricky as they like about leaves, but they stick each to its own pattern, in making acorns. So, in the fall, when the acorns drop, you can study the oaks again.
After these tantalizing oak leaves, it is always such a comfort to turn to the American elm. That tree can always be depended upon to make a certain leaf. Along its high branches, that curve over in great plumes, the elm sets an oval or egg-shaped leaf about three inches long, narrowest at the tip and just a little pointed. The elm leaf grows singly, on opposite sides of twigs, each a little advanced beyond the last, and making a neat, feathered spray. The leaf is strong, saw-notched, short stemmed and firmly set, smooth above, rough underneath. From the midrib the veins slant upward, making
