The botany of desire: a plant's-eye view of the world Read Online Free PDF Page A

through at its equator, and you will find five small chambers arrayed in a perfectly symmetrical starburst—a pentagram. Each of the chambers holds a seed (occasionally two) of such a deep lustrous brown they might have been oiled and polished by a woodworker. Two facts about these seeds are worth noting. First, they contain a small quantity of cyanide, probably a defense the apple evolved to discourage animals from biting into them; they’re almost indescribably bitter.
    The second, more important fact about those seeds concerns their genetic contents, which are likewise full of surprises. Every seed in that apple, not to mention every seed riding down the Ohio alongside John Chapman, contains the genetic instructions for a completely new and different apple tree, one that, if planted, would bear only the most glancing resemblance to its parents. If not for grafting—the ancient technique of cloning trees—every apple in the world would be its own distinct variety, and it would be impossible to keep a good one going beyond the life span of that particular tree. In the case of the apple, the fruit nearly always falls far from the tree.
    The botanical term for this variability is “heterozygosity,” and while there are many species that share it (our own included), in the apple the tendency is extreme. More than any other single trait, it is the apple’s genetic variability—its ineluctable wildness—that accounts for its ability to make itself at home in places as different from one another as New England and New Zealand, Kazakhstan and California. Wherever the apple tree goes, its offspring propose so many different variations on what it means to be an apple—at least five per apple, several thousand per tree—that a couple of these novelties are almost bound to have whatever qualities it takes to prosper in the tree’s adopted home.
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    Exactly where the apple started out from has long been a matter of contention among people who have studied these things, but it appears that the ancestor of Malus domestica —the domesticated apple—is a wild apple that grows in the mountains of Kazakhstan. In some places there, Malus sieversii, as it’s known to botanists, is the dominant species in the forest, growing to a height of sixty feet and throwing off each fall a cornucopia of odd, applelike fruits ranging in size from marbles to softballs, in color from yellow and green to red and purple. I’ve tried to imagine what May in such a forest must look—and smell!—like, or October, with the forest floor a nubby carpet of reds and golds and greens.
    The silk route traverses some of these forests, and it seems likely that travelers passing through would have picked the biggest and tastiest of these fruits to take with them on their journey west. Along the way seeds were dropped, wildlings sprouted, and Malus hybridized freely with related species, such as the European crab apples, eventually producing millions of novel apple types all through Asia and Europe. Most of these would have yielded unpalatable fruit, though even these trees would have been worth growing for cider or forage.
    True domestication had to await the invention of grafting by the Chinese. Sometime in the second millennium B.C., the Chinese discovered that a slip of wood cut from a desirable tree could be notched into the trunk of another tree; once this graft “took,” the fruit produced on new wood growing out from that juncture would share the characteristics of its more desirable parent. This technique is what eventually allowed the Greeks and Romans to select and propagate the choicest specimens. At this point the apple seems to have settled down for a while. According to Pliny, the Romans cultivated twenty-three different varieties of apples, some of which they took with them to England. The tiny, oblate Lady apple, which still shows up in markets at Christmastime, is thought to be one of these.
    As Thoreau suggested in an 1862