April/May 1984 | Volume 35, Issue 3
Banished from public view in our cities, this two-hundred-year-old import is alive and well behind the scenes
“But the tree hadn’t died … it hadn’t died.
“A new tree had grown from the stump and its trunk had grown along the ground until it reached a place where there were no wash lines above it. Then it had started to grow toward the sky again…”
The girl who took heart from the tree’s indomitability was, of course, the teenager Francie Nolan, whom Americans came to love and admire in Betty Smith’s best-selling 1943 novel, A Tree Grows in Brooklyn , and whose stubborn resourcefulness the tree symbolized. The tree itself, as Brooklynites have learned, was the ailanthus, or tree of heaven, which was introduced into this country just two hundred years ago. It was altogether appropriate that Francie’s revered ailanthus was growing in her backyard, for even by World War I, the years in which the novel is set, the tree, once considered a suitable embellishment for the finest homes and boulevards, had fallen from grace and been condemned as a weed. Unruly, perhaps even noxious, it was just the kind of growth you would find in slum neighborhoods like the Nolans’. Indeed, wrote Betty Smith near the beginning of the book, it could be a harbinger of a neighborhood’s decay. If you went for a walk in a refined section of town and saw an ailanthus growing in someone’s yard, “you knew that soon that section of Brooklyn would get to be a tenement district. The tree knew. It came there first.”
The tree of heaven had not always had it so bad. For at least the first half of its two hundred years here the ailanthus was esteemed for its abundant foliage, its handsome form, its rapid growth, and its amazing imperviousness to disease. During the remainder of the period it has been steeped in controversy. Its critics say it is uncontrollable. Its defenders concede its faults, but they insist that it has been unjustly maligned.
Even to those unacquainted with botanical niceties, the ailanthus is easy to spot. It bears exotic-looking compound leaves somewhat resembling fern fronds, with small leaflets alternating on a stalk that may be anywhere from eighteen inches to a yard long. The effect, when the leaves sway in a breeze, is of a tropical tree—which is no coincidence, as the ailanthus is cousin to such tropical trees as the cashew and mango. Mature ailanthuses, with their smooth, gray bark, commonly reach forty or fifty feet in height, although some may climb above one hundred feet and there is a hundred-year-old specimen on Long Island with a trunk over nineteen feet in circumference. The ailanthus is found over most of the United States.
Every June, unfortunately, the ailanthus may be further identified by the disagreeable odor emitted by the flowers of the male (the female is not so afflicted). The trait has earned it the nickname “stink tree.” Later in the summer a keen observer may spot the seed floating away from the tree, borne by propellerlike wings that carry it far and wide and are responsible for its formidable ability to spread rampantly. Once rooted, it leaps up, often growing as much as twelve feet in a year.
The most beloved—or notorious—characteristic of the ailanthus, however, is its tenacity. The more wretched its surroundings, the more it seems to thrive, and to date it has proved to be unaffected by pollution. Give it a handful of cinders, plaster dust, or crushed asphalt, and it will flourish; a New York poet once remarked that ideal growing conditions could be provided for it by two dead vine leaves, a cigarette butt, and a paper clip. It is also extraordinarily difficult to eradicate: cut it to the ground, and it will swiftly send up new growth. Betty Smith summed up its fortitude: “No matter where its seed falls, it makes a tree which struggles to reach the sky. It grows in boarded-up lots and out of neglected rubbish heaps. It grows up out of cellar gratings. It is the only tree that grows out of cement. It grows lushly … survives without sun, water, and seemingly without earth. It would be considered beautiful except that there are too many of it.”
But the tree was once deemed beautiful, not only by the untold Francies of this world but also by experts. The tree is a native of China and was first brought to the attention of Europeans by a Jesuit priest named Pierre dlncarville who was traveling in the Orient in the 1740s. Eighteenth-century Europeans were constantly on the lookout for trees of the Far East and Pacific that might have economic value for the West. (An assignment to carry breadfruit trees from Tahiti to the West Indies was what started HMS Bounty on her ill-fated mission in 1787.) Incarville mistakenly thought the tree was a Chinese varnish tree, which was valued as a source of lacquer. He shipped some seeds to friends in Paris, who sent a batch to botanists in England. One Britisher, Philip Miller of the Physic Garden at Chelsea, decided correctly that it was not a varnish tree but something not hitherto seen in the West, and he named it Toxicodendron altissima —the first name because, although it was lovely, it gave him headaches, the second because it grew tall.
In 1784 the tree was introduced into America by a prominent Philadelphian, William Hamilton, who is known for being the first importer of several other trees now common in the United States, among them the ginkgo, the Norway maple, and the Lombardy poplar. The luxuriant, rapid growth of Hamilton’s new import attracted wide attention, but Miller’s Latin name for it was not readily accepted. The situation was further confused shortly thereafter by a French botanist, René Desfontaines, who felt certain he had seen the species illustrated in a book about the flora of the Molucca Islands, northeast of Java. The Moluccan tree was the ailanto , a local word meaning “tree of heaven”—again because it grew tall. Desfontaines converted the name to ailanthus , and his label caught on. But Miller’s label also persisted, and all during the nineteenth century the tree carried two competing names. Only in this century did authorities settle on a name that, though somewhat redundant, gives credit to both Miller and Desfontaines: Ailanthus altissima .
Meanwhile, the plant itself was catching on in the United States. Early settlers in need of a quick-growing tree were delighted by its vigor. They also noted that it made excellent firewood, yielding a clean, hot flame which rivaled that produced by oak, black walnut, or birch. When experts reported that its leaves were eaten in China by larvae that produced tough pongee silks, widespread but unavailing efforts got under way to found a silk industry based on the ailanthus in this country. Cabinetmakers liked it; it was strong and took a high polish. And when properly seasoned, they said, it would not shrink or warp.
Most suprising in view of its later downfall, however, was its initial popularity as a street tree. Admittedly this was due at least in part to the promotional efforts of a Long Island nurseryman named William Prince, who imported large numbers of the tree starting around 1820 and persuaded New Yorkers to plant it everywhere. By 1840 it had displaced the more disease-prone linden and the horse chestnut along the city’s thoroughfares and side streets. But it was also being set out along the streets of Boston and Baltimore, both of which needed a tree resistant to soot and smoke. No less a horticultural eminence than Charles Sargent, founder and first director of Boston’s Arnold Arboretum, declared that “for hardiness and rapidity of growth, for the power to adapt to the dirt and smoke, the dust and drought of cities, for the ability to thrive in the poorest soil, for beauty and for usefulness, this tree is one of the most useful which can be grown in this climate …”
The ailanthus was also taking root on its own all across the country. By the 1880s it was running wild in Virginia and neighboring states and becoming thick around St. Louis. It also had become plentiful in the foothills of California’s Sierra Nevada; historians presume that the seeds were brought from China, perhaps by Chinese immigrants hired to work in the mines during the gold rush.
Slowly, however, word got around that the ailanthus had a few faults. Its ability to grow anywhere could become positively invasive: if you chopped an ailanthus seedling down in one place, it might sprout again ten or a hundred feet away. Cabinetmakers became disillusioned too: the ailanthus looked strong, but the young wood had a tendency to split. Street maintenance personnel noted the same trait: high winds or snowstorms split the trunks or branches, necessitating massive cleanup work. Worst of all was the aroma of the male blossoms: botanists knew that the scent attracted insects and was therefore crucial to the tree’s reproductive cycle, but humans strolling beneath the tree were not charmed.
The objectionable smell, in fact, was soon suspected of being harmful. When the ailanthus was first introduced, it was advertised as healthful, as its luxuriant foliage would absorb noxious vapors and thus enhance people’s well-being. Malaria, for example, was thought to result from breathing bad air; maybe the tree of heaven could prevent it. But when the incidence of sickness failed to drop, people turned around and blamed the ailanthus. “Might not this tree,” said one opponent, “which so fully absorbs poison, also throw off toxic effluvia? May it not store up the noxious gases and again let them forth in the flowering season?” The stink tree had become a villain. Botanists began reporting cases of “ailanthus fever”: one man in Boonsboro, Maryland, suffered from sore throat, nausea, and inability to sleep at night for three weeks.
There was indeed, and is, a mild medical problem. The odoriferous male flowers produce pollen that the wind distributes far and wide, and some people are allergic to it. But more allergies are produced by the pollen of such standbys as beech, birch, elm, oak, and poplar. The tree is actually more menacing to other plants than to people. According to some botanists its leaves contain a substance that leaches out with the rain and runs into the soil and is mildly toxic to both evergreens and deciduous trees growing nearby. Thus does the ailanthus guard its turf. Cities stopped planting the ailanthus; New York banned its use as an official street tree, as did other communities. The anti-ailanthus campaign culminated in an ordinance adopted in 1875 by the District of Columbia: “That ailanthus trees, the flowers of which produce offensive and noxious odors, in bloom, in the cities of Washington and Georgetown, or the more densely populated suburbs of said cities, are hereby declared nuisances injurious to health; and any person maintaining such nuisance, who shall fail, after due notice from this board, to abate the same, shall, upon conviction, be fined not less than five nor more than ten dollars for every such offense.” The ordinance is still on the books in the nation’s capital.
Other countries, blessed perhaps by less invasive varieties, look with favor on the ailanthus. New Zealanders cultivate it for timber. The British enjoy its pleasing form and do not find that it spreads unduly. In fact, the Royal Horticultural Society distributes ailanthus seeds free to its members. The Chinese, for their part, have never ceased to approve of it. They affectionately call it the “spring tree,” as it is one of the last to leaf out in the springtime and can thus be relied on to show that the hard winter is finally gone. Ailanthus wood is used to make the kitchen steamers that are essential to much of Chinese cuisine. In times past, the root of the tree, ground up and mixed with the urine of small boys, was considered good medicine for persons who were psychologically unbalanced; ailanthus leaves, pulverized with those of the catalpa and the peach tree, were thought to help cure baldness when they were smeared over the head.
In the United States it continues to please millions who are glad for the greenery it provides where otherwise there would likely be none. Some horticulturists believe that careful breeding might produce an ailanthus that would spread yet smell less, though no such program is under way. “If we could only make it sterile,” says one arboretum official, “we’d have a very fine ornamental tree that everyone could plant.”
Now and then in America the ailanthus still officially wins out. A few years ago in New York City a developer threatened to cut down a seventy-year-old, five-storyhigh specimen that was in the way of his bulldozers. Neighbors objected and took him to court, whereupon the judge ruled against him. The tree was to stay. Francie Nolan would have cheered.