The Purpose Of The Tree

Fruits of our common forest trees, though sometimes as inconspicuous and nearly as fleeting as the flowers that produced them, offer such ingenious contrivances for our admiration that they rival them, not in exquisite delicacy of parts, but in intricate structure, variety of forms, interest, and in charm. They are well worth our study. The outer covering of the fruit, which gives the characteristic shape and is never showy in color, is for protection and is also designed so that it will carry the fruit to favorable germinating spots. Within is the vital part, the baby plant, or the seed carefully protected in turn by its own covering.

The seed, we know, is always the result of the combination of the pollen from the staminate flower with the ovule of the pistil within the pistillate flower. But we cannot always trace the origin of the outside covering because, depending upon the species, different parts of the flower develop to form it.

Sometimes parts of the flower are wholly suppressed and sometimes are united in its development, making the study of the fruit rather more perplexing than that of any other organ of the plant. The finding of the fruit is often a helpful complementary asset in identifying trees.

There is such a wide variation in form and appendages, such pronounced individuality that it is easy to distinguish a maple key from an elm samara or an ash paddle, although all three have wings; an acorn from the fruit of the hickory though they are both nuts, or a flattened, dark reddish honey locust pod, spirally curved to be caught and rolled by the wind, from the long, spike-like pod of the catalpa packed to utmost capacity in a most orderly fashion with thin, gray, oblong fruits fringed at the ends.

The fruit alone, however, cannot be depended upon as a means of identification. Trees are often permanently or temporarily barren. Those like the ashes, some maples, and the poplars, which produce staminate and pistillate flowers on separate trees will, of course, produce fruit only on the tree bearing pistillate flowers. Some trees, as the beech, may grow to good size and still be too young to bear fruit, and, again, some species of trees do not bear every year.

The purpose of the tree is to have its seeds conveyed by wind or gravity to spots some distance away where they may find air, and sunshine, and homes in new soil rich in the elements needed for their growth.