These statements are easy enough to make, but it is impossible to demonstrate whether the common pomological apples are derived from one original species or from two or more. Many technical botanical names have been given in the group, but we need not pause with them here. It is enough for our purpose to know that the natural-history of the apple, as of anything else that runs to time immemorial, passes at the end into obscurity. We seem never to reach the ultimate origins or to find an end to our quests.
There are other apples than the common pomological orchard types. There are the crabs. In general usage, the word "crab" designates an apple that is small, sour and crabbed. Such apples are wildings or seedlings. They are merely depreciated forms of Pyrus Malus, and probably much like the first apples known to man. What are known to horticulturists as crab-apples, however, are other species of Pyrus, of different character and origin. We need not pause with the discussion of them, except to say that the commonest kinds are the little long-stemmed fruits of Pyrus baccata (berry Pyrus), native in eastern Europe and Siberia. These are the "Siberian crabs." The leaves and twigs are smooth, and the calyx falls away from the fruit, leaving a bare blossom end. These little hard handsome fruits are used in the making of conserves. Certain larger crab-apples, in which the blossom end is not clean or bare, as the Transcendent and Hyslop, are probably hybrids between the true crabs and the common apple; this class provides the main crab-apples of the markets.
When the settlers came to the country west and south of New England, they found another kind of crab-apples in the woods, truly native. The fruits were hard and sour, but they could be buried to ripen. The trees are much like a thorn-apple,—low, spreading, twiggy, thorny; but the pink-white large fragrant flowers are very different. The wild crab-apple was called Pyrus coronaria by Linnaeus, the "garland Pyrus." On the prairies is another species, Pyrus ioensis; it yields a charming double-flowered form, "Bechtel's crab." In the South are other species. In fact, P. coronaria itself may not be a single species. These wild crabs run into many forms. In the northern Mississippi and prairie country are native apples good enough to be introduced into cultivation under varietal names. These are Pyrus Soulardii, a species bearing the name of J. G. Soulard, Illinois horticulturist. These crab-apples are probably natural hybrids between Pyrus Malus and the prairie crab, P. ioensis. Had there been no European apple to be introduced by colonists, it is probable that improved forms would have been evolved from the native species. In that event, North American pomology would have had a very different character.
There remains a very different class of apple-trees, grown only for ornament and usually known as "flowering apples." They are mostly native in China and Japan. They are small trees, or even almost bushes, with profuse handsome flowers and some of them with very ornamental little fruits. They have come to this country largely from Japan where they are grown for decoration, as the cherries of Japan are grown not for fruit but for their flowers, being of very different species from the cherries of Europe and America. The common apple itself yields varieties grown only for ornament, as one with variegated leaves, one with double flowers, and one with drooping branches. These are known mostly in Europe; but these forms do not compare in interest with the handsome species of the Far East.
All these differing species of the apple-tree multiply the interest and hold the attention in many countries. They make the apple-tree group one of the most widespread and adaptable of temperate-region trees. It will be seen that there are three families of them,—the Eurasian family, from which come the pomological apples; the North American family, which has yielded little cultivated material; the East-Asian family, abundant in highly ornamental kinds. There are no apple-trees native in the southern hemisphere.
The apple-tree, taken in its general sense, has a broad meaning. What may be accomplished by breeding and hybridizing is beyond imagination.