A Garden of Marvels
Dedication
To Kenneth Greif, mentor of a lifetime
Contents
Dedication
Introduction
Part I: Inside a Plant
one - Cocktail, Anyone?
two - The Birth and Long Life of the Vegetable Lamb
three - Through a Glass, However Darkly
four - The Persecuted Professor
five - Inside a Plant
Part II: Roots
six - Restless Roots
seven - The Enormous Gourd
eight - The Way of All Water
nine - How to Kill a Hickory
ten - Our Fine Fungal Friends
eleven - Arsenic and Young Fronds
twelve - The Once and Future Wheat
thirteen - Off to the Races
Part III: Leaves
fourteen - New Beginnings
fifteen - A Momentous Mint
sixteen - Leaves Eat Air
seventeen - The Vegetable Slug
eighteen - Once in a Blue-Green Moon
nineteen - The Tenacity of Trees
twenty - Amazing Grass
Part IV: Flowers
twenty-one - Sex in the Garden
twenty-two - Who Needs Romeo?
twenty-three - Black Petunias
twenty-four - The Abominable Mystery
twenty-five - Cheap Sex
twenty-six - Scent and Sex
Part V: Onward, Upward, and Afterward
twenty-seven - Trouble in Paradise
twenty-eight - Onward and Upward
twenty-nine - Afterward
Acknowledgments
Notes and Sources
Bibliography
Index
Also by Ruth Kassinger
Copyright
About the Publisher
Introduction
This book was born of a murder, a murder I committed. It was not my first, but I have some hope it will be my last. Since I never set out to kill—quite the contrary—I suppose I am guilty only of negligent homicide, or possibly mere criminal negligence. Still, I feel deeply culpable. All I can do is plead ignorance, and say that this particular death was a life-changing event for me (as well, of course, for my victim). Possibly, since you have this book in your hands, the tragedy will save a few lives I will never know.
The deceased in this case was a twelve-year-old guest, a permanent resident, really, of my household. She was a lovely, graceful creature about five feet tall, and a particular favorite of my family. Kam Kwat she would have been called in Cantonese, had she lived in her native land. As it was, since we live just outside Washington, D.C., we knew her as the kumquat tree. In the summer she lived outdoors on our patio in a cobalt-blue pot; from late fall through winter and into spring she lodged in the small conservatory attached to the side of our house. I carried out the murder—and I can’t help feeling her death deserves that name—in the conservatory, with the clippers.
The facts are as follows. I brought my kumquat tree home as a three-year-old, an immigrant from a nursery nearby. She was a slender thing, and her gracile limbs, covered in deep green, oval leaves, lifted upward and curved slightly outward, as if their weight were just a bit more than her youthful frame could bear. The following spring she blossomed, flushing with tiny, white, and fragrant flowers. In a week or so, the flowers fell, revealing dark green beads at their bases. These gradually expanded and finally ripened into golden-orange fruits the size of large grapes. Plucked off the tree and eaten in one bite, the fruit had a slight bitterness redeemed by the sweetness of the delicate peel. Even our terrier liked them, and ate any that dropped to the floor.
Every year for five years, the tree grew a few inches taller, and her limbs branched again and again, until she wore a dense and glossy crown. At nine, though, she stopped growing. I was relieved, actually, since the conservatory is crowded in winter after I bring in the orange, lemon, fig, coffee, bay laurel, loquat, and banana trees, and a host of potted herbaceous plants. The following winter, however, she began to decline. The lower leaves on her branches turned yellow and, one after another, fell to the stone floor with a delicate rattle. By early spring when I moved her outside again, she held skinny, bare arms to the sky; only their very ends were leafy, as if she were wearing nothing but green gloves. Was this a watering problem? I’m a lackadaisical gardener, so I tried to be more conscientious with my watering can. Was she hungry? I sprinkled her soil with fertilizer pellets. I repotted her into a larger container.
Nothing helped. I looked to Ted, my husband and a more accomplished gardener, for inspiration. We have a strict division of labor in our household: I take care of the indoor plants and Ted tends to the outdoor ones. Years ago, he planted a crape myrtle just outside a living room window, and early every spring, before its new leaves appear, he prunes its multiple trunks back to windowsill height. About the same time, he razes the hedge of Knock Out rosebushes that line our driveway, reducing them to a two-foot-high stubble. Miraculously (to my mind), within weeks all the plants leaf out. By mid-May, we have rosebushes hectic with red blooms. In July, the crape myrtle is weighted with magenta flowers that fill the window frame, just where we can enjoy them. There seemed to be a lesson in this for me. I broke out the clippers and gave my kumquat a thorough—really thorough—pruning. Then I put her outside in the sun, and waited.
Her branches turned brown and brittle. I had killed her.
Why? Why did she succumb when the crape myrtle thrived? It occurred to me I had run up against some fundamental biological difference between crape myrtles and kumquat trees, but I had no idea what it was.
This failure brought to mind other local botanical mysteries. Some friends up the street had a beautiful hickory. During a construction project, they added a deep layer of soil to their yard, and although they constructed a tree well around the trunk, the tree died. Why? Why does the vibrant green fescue in our lawn inevitably lose ground to scraggly, tough crabgrass? Why do houseplants, so beautiful and vigorous in the garden center, decline after a few weeks at home, even if I tend to them like a robin doting on her newly hatched chicks? Most immediately, I had two tree-size dracaena, those foolproof foliage plants ubiquitous in offices and shopping malls, whose roots had grown through the drainage holes in their pots and now circled their saucers. Could I safely prune these ugly outliers? I knew the basic rules of caring for indoor plants—drain any water in plant saucers, let the top inch of soil go dry before watering, apply fertilizer in spring—but I realized I understood very little about how roots, stems, leaves, and flowers function, what physical and chemical processes make them work. In other words, I knew almost nothing about the physiology of plants.
How could it be that I knew so little? Here’s one excuse: I’m a suburbanite, and live in a house with a yard the size of a carpet remnant. Yes, where I live oak trees drop acorns, daffodils bloom, and grass (or crabgrass) grows. But vegetation here is a minor component of a landscape dominated by man-made features like houses, streets, and cars. Until I took up indoor gardening, the only thing I pondered about plants was which ones to eat.
Another excuse: I’m a humanities person, and went through college and graduate school without taking a single science course. I was so inattentive in my high school science classes—I was to be a poet, you see—that I was unprepared for even the basic college-level biology course. I came to regret those academic choices, and over the years have learned enough physics and chemistry to write books for young adults on the science and history of inventions and materials. But of plant science, I knew almost nothing. Here’s yet another excuse: High school biology textbooks then (and now) usually devote only a chapter or two to plants, and largely as a warm-up to what is the p
resumably more interesting subject of animal biology.
A few botanical facts did reverberate faintly in my brain, like the half-remembered lyrics of pop songs I listened to in the same era. The words xylem and phloem I recalled because they regularly appear as answers to clues in crossword puzzles. I even knew that both are tubes in a plant for transporting water and . . . and . . . well, and something else. Pistils and stamens are the male and female parts inside a flower, although which was which I had forgotten. Photosynthesis, I knew, involves taking carbon dioxide out of the air while simultaneously producing oxygen. How that transformation occurs, I couldn’t say. I must have daydreamed through Mrs. Miller’s explanation in ninth-grade biology.
When in middle age I began caring for a collection of indoor plants, I turned to gardening books and hang tags for the practical advice I needed. I was moderately successful gardening in this way, although, as I say, Kam Kwat was far from my first failure. It now dawned on me that blindly following instructions—or acting on my own mistaken analogies—without any insight into the science of plants might be part of my problem. Maybe if I knew how a kumquat differs, physiologically, from a crape myrtle, I might avoid another murder. I started off to educate myself, hoping to become a better, or at least a less lethal, gardener.
I began by checking out botany and plant physiology textbooks from the University of Maryland library, and set out to work my way through them. To my chagrin, I made little progress. There was too much information, too much detail. Some was pertinent to my interest as a gardener, some was fascinating but irrelevant, too much was inscrutable. Botany felt like a steep and thorny cliff that I was trying to summit by climbing straight up its vertical face. What I needed was to circle around to the far side and find a gently sloping path to the top. Let there be some curious plants along the way, intriguing historical markers from time to time, and the occasional overlook where I could get a long-range perspective. Maybe I would come across some fellow hikers to chat with as I ambled along.
My primrose path, I decided, would be the story of the first discoverers of the basic facts of plant life. I would go back to the beginning and retrace, step by step and insight by insight, their progress in understanding the way plants work. When I looked for a history of plant physiology, however (as opposed to plant classification), I found little. The only modern chronicle is History of Botanical Science: An Account of the Development of Botany from Ancient Times to the Present Day (Academic Press, 1981), by Professor A. G. Morton at the University of London, and he wrote it for his botany students. It is an excellent book, but hardly the saunter I had in mind. Botany 101 is definitely a prerequisite, and the human side of the story was of little interest to the professor. If he was a gardener, his interest is undetectable. Still, his book made me think that history would be the route I needed.
It turns out that these early explorers of the vegetal world were a diverse, quirky, and unfairly neglected bunch. The men—and they were all men, since we’re talking about the late seventeenth and eighteenth centuries—include a melancholy Italian anatomist, a renegade French surgeon, a stuttering English minister, an obsessive German schoolteacher, and Charles Darwin, who, in the last two decades of his life, devoted most of his intellectual energies to botany.
Intrepid though they were, they uncovered the fundamental facts of botanical science remarkably late, compared to other sciences. In 1670, no one yet knew what lies inside a stem, much less how water moves up a trunk, or what plants eat to grow. Consider that by that date, the anatomist Andreas Vesalius had published accurate descriptions of the human skeleton, musculature, and many internal organs. William Harvey had revealed the basics of the human circulatory system and Thomas Bartholin had discovered the human lymphatic system. Physics was far advanced. Johannes Kepler had developed mathematical laws that define planets’ orbits; Galileo had explained how the Earth revolves around the sun and had seen the moons of Jupiter; and Isaac Newton had invented calculus, discovered the law of universal gravitation, and revealed that sunlight is composed of all the colors of the spectrum. Evangelista Torricelli had invented the mercury barometer and created an artificial vacuum, and Christiaan Huygens had constructed a pendulum clock. Yet no one knew what flowers are for.
There are reasons for botany’s tardiness. Observe a frog and you can see its tongue streak out to snag a fly and its mouth snap shut. Dissect your subject and you can see its throat and esophagus, and how the stomach connects to the intestines. Touch the frog’s quadriceps with a pin, and the muscle contracts and the leg moves. The frog’s heart, lungs, veins, and arteries are obvious, even if how they coordinate is not immediately clear. But look at a tree, a petunia, or a blade of grass, and you understand nothing of its workings. There is no mouth. If it eats anything, its food is invisible. It produces no waste. Cut it open and you are no more enlightened: There is no stomach, no heart, no digestive system, no musculature. The most you discover is that there are softer and harder tissues inside, and that liquids, clear or milky, may leak from the cut. As for reproduction, it might seem that a single plant produces a seed all by itself. Ferns whose spores are microscopic you might reasonably assume generate spontaneously out of nothing. Certainly, no one could guess by merely looking that plants turn sunlight, air, and water into stems and leaves and flowers.
Uncovering the laws of celestial mechanics, where measurements and equations reveal truths, was easier than understanding an onion. The most fundamental questions about plants were hard to answer. No one ever wondered if a comet was some sort of high-flying bird, but botanists struggled with the basic definition of a plant. Some argued that plants were more like stones than animals. Consider this, they said: Knock a piece off a salt crystal and the chip will grow; clip a stem from a plant and the cutting can develop into a new plant. On the other hand, amputate a man’s leg, and it never grows into a new man, and, unlike the crystal and the plant, the man often dies as well. Nonetheless, during the late seventeenth and eighteenth centuries in Europe, in the period known as the Enlightenment, a few men began to look at the vegetal world in a new way, not to see whether plants could be eaten or what diseases they might cure, but to answer a novel question: How do they work? Bit by bit, they revealed the wonders of plant anatomy and physiology.
Those wonders are on display in everyone’s garden—and all of Earth is a garden—but some plants are particularly entertaining to partisans of the natural world. A fern that vacuums arsenic out of contaminated soil, a biofuel grass that grows twelve feet tall, utterly black petunias, one-ton pumpkins, and photosynthesizing sea slugs are curiosities, but also instructive about how roots, stems, leaves, and flowers work. Land plants have been evolving for more than 400 million years, more than twice as long as mammals, and they are stunningly diverse in their strategies for survival. Despite their immobility and lack of muscle tissue, they have developed elegant solutions to the problems of gathering food, transporting water and nutrients around their corpus, and reproducing. It’s a good thing they have: We depend utterly on plants for food, both by eating them directly and by eating animals that have eaten them. The oxygen we breathe is manufactured by plants and photosynthesizing algae and bacteria.
Plants and their seagoing ancestors have always influenced the global climate, and they will be critical in the coming centuries of climate change. Some of the extraordinary plants I investigated for this book give me hope. Miscanthus, that giant grass, is a carbon-neutral biofuel that grows quickly, without fertilizers, noninvasively, and on land too poor for agriculture. The grandparents of plants, photosynthesizing cyanobacteria, can be coaxed via genetic modification into excreting ethanol for fuel. Scientists at the Land Institute in Kansas are developing perennialized versions of annual crops that would sprout anew each spring from underground root systems. By reducing annual tilling of millions of acres, we could slow down topsoil erosion, which is a serious problem in the United States and around the world, and rebuild soil fertility. Researchers at the Universi
ty of California, Riverside are working to unlock the secrets of a plant hormone that might help crops survive the stress of drought. The International Rice Research Institute is trying to develop rice varieties that incorporate the variant of photosynthesis that makes crabgrass so damnably successful in my backyard.
So, welcome to the garden of marvels, past, present, and future.
PART I
Inside a Plant
one
Cocktail, Anyone?
It is mid-July in mid-Florida. The sky is one vast sheet of burnished aluminum, pristine except directly overhead where some celestial welder is blazing a large and fiery hole. Fortunately, as I cross the rutted yard from where I’ve parked my rental car, I feel a light breeze, a minor but meaningful dispensation.
I am here to see Charles Farmer, the owner of this citrus nursery. A small trailer, which I assume is the office since it is the only building in sight, sits on cinder blocks not far from the entrance gate, but no one answers my knock. I worry that perhaps he has forgotten our appointment today, but then I hear a radio playing somewhere out back. Skirting a temporary swamp left from last night’s downpour, I follow the sound to a large greenhouse, push through the outer door, and let it close before opening the inner door.
Inside, there is no breeze at all. The air is absolutely still, bright with sunlight and dense with heat concentrated by the translucent roof. Two people are working at the far end of the structure, and I wave and start down toward them, between rows of waist-high benches covered in potted, two-foot-tall saplings. Sweat breaks out on my upper lip. By the time I’m close enough to call hello, my face is slick.
Never mind. I am near the end of a quest, and somewhere in this greenhouse is the object of my desire, a tree that I have been thinking about for years. Somewhere in this structure is a citrus cocktail tree, a single tree whose branches bear many different kinds of citrus fruit.