Part 18

The tulip tree has a large leaf of peculiar form. It is broad like a maple leaf at the base, but at the tip it is cut off square as if with a pair of shears, forming a right angle with its straight sides. Sometimes the leaf is notched, as if a V-shaped piece were cut out of the square tip. These leaves are long-stemmed, their blades polished, and they flutter on the twigs with the lightness of a poplar leaf. Once we have in mind the form of the leaf of the tulip tree, we shall never forget it, for it is different from all other leaves.

The catalpa tree, which lifts its great blossom clusters above the foliage in late June, is another of the few large-leaved trees of the North. The single blade is heart-shaped, six to eight inches long, and more than half as broad. These leaves usually have plain margins, but sometimes they are wavy and notched near the base so as to produce faint side lobes. The blades hang on long, stout stems.

Among the feather-leaved trees, the walnuts and butternuts, the sumachs, and the ailanthus, furnish examples. A black walnut leaf is often two feet long, with a dozen or more leaflets on the longest ones. These leaflets are always set opposite in pairs, with an odd one on the tip of the leaf stem. Butternut leaves have the same form, but the leaves are longer. They range from fifteen to thirty inches, and have from ten to twenty leaflets, but always an odd number. The peculiar gummy feeling of these hairy leaves, and their pungent butternut odour when bruised, make it easy to know the tree wherever we meet it, through the long summer.

The hickories are cousins of the walnuts, but their leaves, though of the feather form, have larger and fewer leaflets than any walnut tree. A shagbark hickory leaf has one or two pairs of little leaflets on the stem, and above them three of larger size. The pignut has the same habit of clustering its three largest leaves at the tip of the leaf stem, and tapering off at the base with one or two pairs of decreasing size.

The largest of all the compound leaves have branched stems to which leaflets are attached. The main leaf stem’s side branches may yet branch again, forming a twice-branched framework that is set with leaflets, not large, but so numerous as to make the whole leaf surprisingly large. The greatest of these twice-compound leaves is borne by that astonishing, spiny-stemmed Hercules’ club. A single leaf is often four feet long, and nearly a yard wide. There are no leaflets on the main stem; they are on the side branches.

How shall we tell a leaf stem from a twig? Leaf stems do not look like the twigs of the tree. A little practice in looking closely and comparing these leaf stems and twigs will obviate any confusion of the two. The leaf has a bud at its base, and it breaks off easily at this joint.

Among the fine, feathery leaves that are so beautiful and light that they give great beauty to the tree tops are those of the honey locust. These leaves are of the feather type, the slender stems, with double rows of tiny leaflets. Very often we find among the single feather forms, leaves of greater size, which have branched stems. This branching multiplies the number of leaflets, and gives us, on the same trees, what the botanists call once compound, and twice compound leaves. The simple feather and the branched feather forms add greatly to the beauty and luxuriance of the foliage of the honey locust.

The common black locust of the roadside has single leaf stems with oblong leaflets set in opposite rows upon it. Ash trees have the same feather type of leaves, the leaflets usually pointed and oval, and always an odd one at the tip. They are all larger than leaves of the locusts.

In the maple family there is a broad, simple blade, about as wide as it is long. It is a family trait to have three main veins running out from the end of the leaf stem, into the blade. Each of these veins has side branches, and they are connected with a network of smaller veins. Between the tips of these three main veins the leaf is usually notched, so as to divide it into thirds. In the red maple these notches are shallow V’s cut out, leaving triangular points. In the silver maple the leaves are cut by deeper clefts, which reach more than half-way to the leaf stalk. The three lobes are cut with jagged points into an uneven margin. The sugar maple has its three lobes separated by wide, deep clefts, and its margins are irregularly wavy. The box elder, which is a maple, is cleft so deeply that the blade is split into three distinct leaflets, each with its own short stem. This makes a compound leaf of it. It is the only maple with a leaf of more than one blade.

The tree which shows the greatest difference in the form of its leaves is the sassafras, whose oval leaves grow on the same stem with mittens and double mittens—a mitten pattern with a thumb on each side. The hawthorns have small oval leaves with variously cleft borders. There are over a hundred kinds of hawthorns in our woods, and each kind has a leaf different from all the rest; yet a single tree will often show leaves that differ so much from the others in form that we might easily suspect, if some one brought them to us, that each grew on a different tree from all the rest.

Many oak trees have the same habit of leaf variation, so that even a forester has to examine many leaves with care, and with them the buds and the acorns, to make sure that he has called the oak by its right name.

The behaviour of the leaves of a tree depends largely on the length and flexibility of their stems. If they are long, and slender, and supple, the tree-top is in a continual flutter when the wind blows. If they are thick and stiff, they do not catch the breeze as readily, and their blades lie comparatively still when other trees near by may be twinkling and trembling. Leaves with deeply cut borders, like some oaks and maples, flutter much more than leaves like the basswood, whose borders are unbroken. Oak leaves that are deeply cut will rarely lie down flat. The curving bays in its borders cause the leaf to curl, so that no matter what face is presented, the wind gets under and strikes some surface, and sets the leaf to dancing.

The flat leaf stems of the trembling aspen, one of the poplar family, are very flexible, and they are flattened at right angles to the blades of the leaves. When a breeze comes by, it may strike the edge of the leaf, but if so, it catches the flat leaf stem broadside. If it comes from any other direction the leaf trembles, because one of the blades is sure to receive the force of the wind. So the tree top is in one constant tremor, even when the breeze is scarcely sufficient to disturb broad-leaved trees which are near neighbours of the aspens.

Whatever the form and size and shape of its leaf, the tree depends upon its foliage mass for all the life it enjoys, and for all the growth it makes. The soil and the air feed the tree. The leaves and the sun do the work of digesting the food. In the porous wood and bark are the channels through which sap mounts upward to the leaves, and another set of channels which carry the prepared food back, leaving it wherever needed, along the way from tip of twig to tip of root. Whatever is not needed is stored away, to be dissolved as needed and carried to the points where the need is. In spring it is the growing buds that chiefly need this stored food. Its presence explains the miracle of the bursting of blossoms and leaves when spring comes.

One by one the trees of your own yard may be learned by name this summer. The leaves are your sure guide. Trees stay where they are. Once we recognise their leaves and call them by name, we may depend upon finding them still standing the next day we pass them, and their leaves are still held out as the sign of recognition. Every time we pass yonder red maple let us glance at its three-pointed leaf, and fix its shape indelibly in the mind. When we have done this a dozen times, I am sure that we shall be able to pick out all the red maples in town; and if we journey far from home we may find and recognise the same kind of trees by the same sign. More and more as we grow older, we find out that half the pleasure of travelling is the occasional meeting with old friends, be they people or trees.

TREE STUDIES IN THE SUMMER

TREES WITH THE LARGEST FLOWERS

If we set out to find the trees that have the largest flowers, meaning to count only trees that grow wild in our woods, it will save time to go straight south into North Carolina, and climb the foot hills of the Allegheny Mountains. Or it may be that in the fertile valleys that lie between the low ridges we shall first come upon a magnolia, called the large-leaved cucumber tree. Anywhere from North Carolina to Florida, and west to Arkansas, these remarkable trees are likely to be found, in small groups. In cultivation, they are successfully planted as far north as Boston.

Before the tree has attained more than a man’s height it is a wonder, on account of the leaves which measure more than a foot in length, and have their long, green blades lined with white. In June the flowers open—great white bowls, made of waxen petals, in a double row, the inner ones painted purple at their bases, giving the flower a purple centre.

The wind blows the leaves about, and tears them into rags, unless the tree is in a sheltered place. The silvery leaf linings, as white as the blossoms, make it difficult to see that the tree is in bloom, until one is close enough to see the petals. If the leaves were green on both sides the great blossoms, as large as a man’s head, would be seen afar off. The tree would look like a giant rose bush.

From Pennsylvania southward to the Gulf of Mexico, and west to Arkansas and Texas, the evergreen magnolia grows on stream borders, and even on uplands where the soil is not very moist. When this pyramid of shining green leaves lights all its waxen tapers, it is a sight worth a day’s journey to see. Each stiff twig is bent upward, and there a bud appears in spring. A few at a time, the flowers open, and the blooming time lasts till August.

Each blossom is a deep, creamy cup, made of six wax-like petals, surrounded by three white sepals. Inside are many stamens, purple at the base, and a cone of pistils, all grown together.

The leaves are oblong or oval, often eight inches long, thick, deep green, and bright as if polished on the upper surface. The lining is dull green, sometimes covered with rusty down. The paler green and the brighter polish on the young leaves add much beauty to the tree in summer. In winter the leaves get grimy and the tree top is sombre, for most of the foliage has seen much wear and tear.

In autumn the ends of the twigs hold up green cones, made of many furry capsules that end in curved horns. Each capsule splits when ripe, and a scarlet seed, like a berry, hangs out on an elastic thread, and swings lower and lower, until finally it is carried away. Thus the magnolia sows its seeds in winter.

The shining leaves of this magnolia come North at the Christmas season, and are used to decorate homes and churches. Holly, mistletoe, palm leaves, and the beautiful Southern smilax are other Christmas greens now commonly in use. They are all gathered with magnolia and shoots of the long-leaf pine, in the woods down South.

The swamp bay is a magnolia that grows as a shrub to New England, keeping to the swampy lands that skirt the Atlantic coast. Every spring the fragrant, creamy blossoms are to be bought from street Arabs in New York and Philadelphia. A single globular flower is surrounded by a whorl of oval leaves, bright green, but lined with a white, powdery substance that makes them look silver-lined. The flowers are deliciously fragrant, and most beautiful when not spread wide open. The seller often takes the trouble to spring the petals back, to make the blossom seem bigger. The waxy petals turn brown soon after such handling, and all their natural beauty departs.

From Florida westward to Texas this magnolia becomes a slender, tall evergreen tree. The best flowers of this tree are borne on shoots that are produced by pruning back the new growth each year. The largest leaves and flowers are also the handsomest.

The cucumber tree is the magnolia of the North. It is a fine tree in Ontario, Canada, and from this region it spreads south, its range widening like a fan, reaching from Arkansas to the Carolinas, and Mississippi, and Alabama. The tropical appearance of the tree is due to the big, heart-shaped leaves. Their tulip-like flowers are as large as garden tulips, but they make scarcely any show, because they are very much the same in colour as the yellowish-green new leaves that surround them.