Weber StudiesHome , Archives , Reading Room , Search , Editorial Info , Books , Subscribe ,  West Links
Fall 2004, Volume 22.1



Harry WillsonPhoto of Harry Willson.

Tree of Heaven


After thirteen years as a missionary and ten years as a high school teacher, Harry Willson "quit teaching to write." He has published seven full-length books, and two of his plays have been produced. In addition to writing a local newspaper column, he has carefully observed "wildness" as it has come to him in his semi-rural urban setting.


When the neighbors told me that "tree of heaven" is the name of that stuff growing out front, shortly after we moved in, I couldn't believe it. It was a very strange name for a tree that stank as bad as that, especially when one touched it. When my pruning and clearing away put me into contact with the suckers that popped up everywhere, it took a real scrubbing afterward to get that odor off my hands. I often wondered how the plant could have such a name. If there isn't a myth connected to it, there ought to be, I thought.

From the start, the tree reminded me of sumac, which grew wild in empty fields when I was a boy in Pennsylvania. But sumac didn't stink when we grasped it, and it didn't grow big enough to climb, and tree of heaven did. There is a poisonous variety of sumac, poison sumac, as bad as poison ivy, the childhood lore said. Evidently, I was not allergic to it, or happened never to get into it, which would be a wonder. One girl came to school once, hardly able to walk, with eyes puffed up almost shut, and skin covered with white calamine lotion—she had gotten into some poison sumac, they said.

We kids used to enjoy cracking the younger branches open and picking out the dark brown soft inner pith; we called it "peanut butter" but never ate it, which is another wonder and probably a good thing. We tried to make whistles out of the stems, using that hollow center tube, but had little success. We did put it in our mouths, to try to blow the whistle, so evidently, it wasn't poison.

I was sure the tree of heaven out front was related to sumac; it has the same compound leaf system and the same underground lateral root system. Not long ago I found a young trunk, three inches thick, rotted off at the ground. I carried it to the woodpile, thinking it would end up in the fireplace the following winter.

Sometime later, my son bought a didgeridoo—that marvelous and mysterious musical instrument from the aborigines of Australia. He indicated an interest in making one himself; he needed a long, heavy, hollow piece of carvable wood. We went out to the woodpile and cut the end off the dried trunk of tree of heaven. There was no pith, no hollow tube down the center, no "peanut butter." It was solid, tight, good-looking wood. So I began to figure this tree might not be a variety of sumac, after all.

Actually, we don't have just one tree, with suckers. We have a large patch of it in the semicircle enclosed by the highway out front, the Old Camino Real, and our driveway. The trunks can grow to a thickness greater than eight inches, a much more formidable tree than the sumac back East. When we moved here, there were several huge ones, reaching thirty feet high. I cut them down, disliking the odor, and at that time not really regarding sumac as a landscaping species, at all. The destruction was formidable, and in the middle of it, I questioned whether I was doing the right thing.

I often think, here in New Mexico, "If it wants to grow, maybe I should let it." But there are exceptions, like Bermuda grass and Siberian elms—also called Chinese elms—and I thought sumac was another of those.

But this isn't exactly sumac. It's tree of heaven, and I wondered again where that name could have come from. The root system of what we had here was evidently unperturbed by the loss of half a dozen huge trees. It immediately put out new saplings all over that space and by the following spring had created a forest in that space beside the road.

We noticed a beneficial effect—it created a sound barrier between us and the highway traffic. So I left them pretty much on their own and have ever since. Some trunks are now six-inches thick. The young saplings must be controlled—they reach out into the driveway and into the bike lane of the highway, reaching for light, enlarging the space taken up by the system. It's as if it was all one plant, one organism. I have to insist that it keep to its own assigned space. The ground beneath it all is covered with vinca, or periwinkle, which thrives or dies back, depending on rainfall. I do not water the area.

Curiosity, especially about the name, drove me to "research." I started in my favorite place, the dictionary, and was surprised to find "tree of heaven" as an entry: "tree of heaven—a fast-growing ailanthus [ailanthus altissima], native to China but widely cultivated in the US as a shade tree."

I looked up "ailanthus," and sure enough, there it was, also: "ailanthus—[ailanto, the native name in Malacca] any tree or shrub of a genus [ailanthus] of the quassia family, having pointed leaflets, fine-grained wood, and clusters of small, greenish flowers with an unpleasant odor. See tree of heaven."

Keep going, I always say, when it's the dictionary: "quassia—[Surinam, used in medicine, furniture] any of a genus of shrubs and trees of the quassia family; the wood of either of two tropical trees; a bitter drug extracted from this wood, used in insecticides and formerly in medicine; adj. a family of tropical American shrubs and trees with alternate pinnate leaves, including ailanthus, tree of heaven, and quassia." Dictionaries begin to go in circles, as one can see from this, but it was not a bad start.

Two entries, for "sumac" and "poison sumac" indicated that that was my own personal blind alley—Arabic name, cashew family, clusters of red, hairy fruit—yes, I remember that, and the tree of heaven has no such thing.

Research can turn into the pursuit of a receding goal. I went to the library and found a marvelous book—Best Plants for New Mexico Gardens and Landscapes, by Baker H. Morrow, published by The University of New Mexico Press. There is a beautiful picture of the tree, maybe somewhat flattering, I thought, like the author's likeness on the back cover of a book. And, there is this description, which I record in full here:

"Tree of HeavenAilanthus altissima—Naturalized deciduous tree found statewide. With salt cedar and Siberian elm, the most maligned tree in New Mexico. Grows anywhere, in any soil, with any amount of water and care. Profuse suckers, or water roots. Often found in ruined gardens and on the sites of abandoned towns. Up to 30 feet tall, spreading to 20 feet. Profuse flowers and seeds; the male is reputed to produce a disagreeable odor. Despite its difficulties, ailanthus can make a very pleasant shade or street tree in the right setting, and its fast growth generates much-needed shade. Curiously, it does not transplant well."

"…Ruined gardens… abandoned towns"—the words helped me remember some details. That patch of ground where our tree of heaven sound barrier grows is a ruined garden. Someone had a dream of an oriental garden, right beside the highway. It had a small, shallow pond, with cemented bottom, no water, and a small, low-arched Zen-looking bridge crossing to nowhere, blocked by the time I arrived by a formidable trunk of thriving tree of heaven. It's strange how research helps one think of details that were passed over at the time and never brought to mind since.

Other references to ailanthus in the index of Dr. Morrow's book led to descriptions of the flora of several New Mexico towns, which feature plenty of tree of heaven: Carlsbad, Estancia, Santa Rosa, Silver City, Truth or Consequences, Tucumcari.

"Curiously, it does not transplant well," Dr. Morrow says. Yet it is here and everywhere. So, how did it get here? I called the Biology Department of the University of New Mexico, and finally reached Tim Lowrey, director of the UNM Herbarium. I put my questions to him, and he answered:

[1] No, it is not closely related to sumac.

[2] It was brought here by Chinese railroad workers, the ones who built the western end of our railroad system more than a hundred years ago.

[3] The name ailanthus means "reaching for the sky," so "tree of heaven" can be inferred from that.

That's two references to China and Chinese. I took my research to that bottomless pit of information, the Internet. I typed in one word, "ailanthus"—the eleventh reference was the jackpot: Wyith R. Cheng Associates, Hong Kong—Traditional Chinese Medicine—Materia Medica. One page, entitled, "Ailanthus Bark." Tree of Heaven bark. "Cortex ailanthi. Ailanthus altissima." There were references to "meridians—large intestine, stomach, liver." There was a description of how to obtain the bark. And then a mention of its "functions":

[1] to clear heat, dry dampness and stop leukorrhea

[2] to astringe the intestines

[3] to stop bleeding

[4] to kill worms

Ailanthus bark is used to control diarrhea or dysentery and menorrhagia or uterine bleeding. So, the Chinese railroad builders brought this plant here, and now we know why—it was a very important medicine.

By now, I've almost reached the same point as the little girl who took a book back to the library, telling the librarian, "It tells more about penguins than I want to know." I now know more about ailanthus, and I call it that now, than I ever dreamed would be necessary.

Tree of heaven. I find myself paying attention more than before, noticing where it's growing, where it's giving its generous shade. I wonder if anyone here in town uses ailanthus cortex for diarrhea or menorrhagia. Do they send to Hong Kong for it, or do they grind the bark that grows so plentifully here? The tree is all over the valley, north and south.

The plant still gives off an unpleasant odor when touched, especially when grasped while being pulled up or broken off. No doubt it is the plant's defense mechanism, and it works. No species eats it. The leaves are never chewed on by insects, as are those of the Siberian elm or the Carpathian walnut.

In May, the area is covered with blossoms, most of them high in the air. One can distinguish male from female trees, and here in our yard the bad smell comes from both. The blossoms give off a distinctive odor, not exactly offensive, as when one grasps the stem, but related to it, reminiscent of it. We can smell it when we drive into our place from the highway.

I began to compare odors in my mind. Someone once gave us a houseplant and said it was "carrion plant." It was a strange, ugly thing, fascinating in its oddness, with peculiar jointed, succulent stems and leaves, and big, squarish brown flowers. And stink! We couldn't keep it in the house. We put it out under a pyracantha bush and watched it from a distance. It drew flies. The odor was dreadful, and entirely bad, insufferable.

Ailanthus odor reminds me a little of the scent of skunk. I don't mean that that's what it smells like—I refer to the fact that a little skunk, from a distance, is not at all unpleasant. It's the direct dose that offends. Tree of heaven is like that.

When we harvest honey, after the bees have been working the ailanthus blossoms, we discover magic. We even call it "magic honey." There is a very subtle addition to the sweetness. On that account we believe the tree of heaven is correctly named after all, but one has to taste the honey to believe it.

Back to Top