A Garden of Marvels Read online

  Dean takes me outside to see one of the miscanthus fields descended from those rhizomes. From a distance, the field reminds me of the blocky mesas that rise abruptly out of the landscape in the American Southwest, except, instead of ochers and beiges, here the hues are emerald and dark green. As we approach, the mesa reveals itself to be a dense mass of vertical canes well clothed in bladelike leaves. The whole assemblage sways and shivers in the morning’s brisk breeze. Dean urges me to stay back a minute to take a photograph, and he strides ahead to position himself at the front edge of the field. With Dean in the photo, it is clear that the plants are already nearly twice his six-foot height, and it is only mid-July. Giganteus, indeed.

  A stand of Miscanthus giganteus.

  When Dean and I stand at the edge of the field to look more closely at the plants, I can see that the leaves, dark green with a thin, white stripe down the midline, emerge at every joint of a segmented cane. With two hands, Dean grabs a cane near its base and, tugging hard, pulls it out of the ground, along with its subterranean anchor. He is careful not to grab the leaves, which are covered in microscopic silica, a deterrent to insects and small herbivores. (He recently got in trouble with his wife, he tells me sheepishly, for letting their two youngest sons play hide-and-seek in a miscanthus field. When his wife put the boys in a bath with Epsom salts that evening, they shrieked with the sting from invisible cuts.) He snaps off the cane and hands me what looks like a piece of thick, gnarly root about eight inches long. It’s not really a root, he explains, but a rhizome, a stem that grows horizontally underground. The rhizome is segmented, and each segment or node has a large and stubby bud. The buds are capable of producing either a new rhizome, a fibrous root, or a new cane, depending on the hormonal signal they receive. Over time, many of the buds will become new canes.

  Although it is the tough canes that are harvested for biofuel, it is miscanthus’s leaves that are key to its success. Grasses are newcomers to the planet’s flora, coming on the scene just as the dinosaurs vanished 65 million years ago at the end of the Cretaceous. No one knows for sure why they evolved so late in the geologic day, but climate change likely played a role. At the time, the higher latitudes in the continents’ interiors were becoming more arid and fires more frequent. Grasses are well adapted to fire because their growing tips are at or even below ground level where, sheltered from flames, they can regenerate that very season. Trees, on the other hand, are either killed outright or take years to recover.

  The evolution of large mammals in the post-Cretaceous era also helped the grasses evolve. By 55 million years ago, grazing hoofed animals, the ancestors of modern horses, antelopes, cattle, and camels, were clipping the tender tips of shrubby plants and small trees, stunting or killing them and opening more territory for grasses. Grazing animals might munch grasses to the ground, but when the herd moved on, the grasses sprang up again. By ten million years ago, temperate regions were covered in vast grasslands much like the modern prairies of North America, steppes of Eurasia, pampas of South America, and veldt of southern Africa.

  About that time, in hotter, drier environments closer to the equator, a new class of grasses, what you might call supergrasses, proliferated. These species are today’s critical food crops of sugarcane, corn, millet, and sorghum, as well as bamboo and (ta-da!) miscanthus. The key to their success was their reinvention of photosynthesis.

  Most plants and the older grasses photosynthesize in a “C3” fashion, and as successful as they were and are, they have a physiological weakness. One of the steps in fixing atmospheric carbon dioxide into sugars involves the enzyme RuBisCO. But, RuBisCO regularly makes a mistake and fixes oxygen instead of carbon dioxide. The plant then needs to shed that oxygen, and in doing so, loses some carbon it recently trapped. In hot weather, the problem gets worse. When plants need to conserve water—that is, when they are losing more water through evaporation from their leaves than their roots can replace—their stomata automatically close. When the stomata close, waste oxygen can’t escape and accumulates—and is fixed by RuBisCO—in the leaves. In hot conditions, C3 plants make fewer sugars.

  Certain grasses in the tropics evolved a couple of anatomical and physiological tricks that allowed them to get around this inefficiency. These “C4” plants developed a new biochemical pathway (only discovered by scientists in 1966) that starts by putting carbon into a four-carbon, instead of a three-carbon, compound (hence “C4” and “C3”). That compound is pumped into bundle-sheath cells, the cells that surround leaf veins. In C4 plants, the bundle-sheath cells themselves photosynthesize, while in C3 plants they typically do not. More important, in the C4s these cells are able to concentrate carbon dioxide at a higher level than is in the atmosphere. RuBisCO therefore contacts and interacts with more carbon dioxide molecules than it otherwise would, so more sugars are created. Because the bundle-sheath cells are impermeable to oxygen, less wasteful oxygen fixation occurs.

  In sum, C4 plants learned how to make more hay—about 40 percent more—while the sun shines. That is why although they represent only 1 percent of the world’s plant species, they represent 20 percent of the Earth’s vegetation coverage and produce about 30 percent of terrestrial carbon. That is also why fourteen out of the eighteen of the world’s worst weeds (we’re looking at you, crabgrass and pigweed) are C4 species. And that is why miscanthus is a prime candidate for making biofuel. Moreover, it turns out that among C4s, miscanthus is especially good at accumulating carbon, even in a climate as untropical as Ontario. In the spring, miscanthus sends up new shoots from its rhizomes several weeks earlier than corn, which has to develop from seed, and even switchgrass. Its leaves continue to photosynthesize weeks after those two have called it a season. I am not surprised to learn, looking at the impenetrable mass of leaves in front of me, that miscanthus has more leaves with a larger collective surface than other C4s.

  By the spring of 2008, using a combination of microscopic tissue culture and by manually dividing and redividing rhizomes, Dean turned Dr. Long’s five rhizomes into thousands, and planted them on sixty acres. By the end of one growing season Dean had ten times the number of plants that the university had. By 2014, Dean expects his tomato farm will be energy self-sufficient.

  The psychological benefits of energy independence are considerable, but does growing miscanthus make business sense? Dean has four hundred marginally productive acres of his own in miscanthus, and he contracts with neighboring farmers to grow the rest. Dean figures that the cost of a gigajoule (a billion joules) of miscanthus-made energy is $4.20. Natural gas, which is cheap at the moment, costs about $6.50 per gigajoule. It doesn’t take a special furnace to burn the biofuel. At least on paper, miscanthus fuel is a winner.

  The environment comes out ahead, too. Burning coal, natural gas, and oil that has been sequestered underground since the Carboniferous era releases climate-warming carbon dioxide into the atmosphere. While burning miscanthus in the winter adds carbon dioxide to the atmosphere, miscanthus took that carbon dioxide from the atmosphere in the spring and summer as it grew. The only fuel Dean uses in producing miscanthus energy is a little diesel for harvesting and baling the crop. In three years, he expects his farm will be nearly carbon neutral, which in a world where carbon dioxide levels are rising at an unprecedented rate is a significant accomplishment.

  There are other environmental benefits, as well. Over the course of a summer, as the canes grow, the older, lower leaves fall off. They decay gradually, and will eventually return carbon and nutrients to the soil, but until then, the thick leaf litter provides good cover for small wildlife. The fallen leaves also slow evaporation from the soil. The underground portion of a miscanthus plant is equal in mass to the aboveground portion, which means it has a substantial impact on the subterranean ecology. The perennial roots of miscanthus reach deep into the ground, where they aerate the soil, leak nutrients to worms and insects, and add organic material to create a rich subterranean ecosystem. In terms of environmental impact, it is a cro
p much like perennial wheat, the holy grail of the Land Institute. Even better, it grows where no self-respecting wheat would grow.

  Denmark, Spain, Italy, Hungary, France, and Germany have started multiple research and commercialization projects, and the European Union projects that 12 percent of its energy will come from miscanthus by 2050. In the United States, the USDA is supporting projects that are expected to have 100,000 acres in miscanthus. BP recently invested $500 million for miscanthus research at the University of Illinois.

  I am fascinated by the prospect of new biofuels in general, and intrigued by miscanthus. When Dean tells me it would probably take about an acre and a half of miscanthus to heat a typical house in Ontario, I mentally add a good stand of miscanthus to my dream house, the one in the country where I won’t have to wonder whether a neighbor’s leylandii will fall on my roof. Miscanthus can’t fill all our energy needs. You can’t put miscanthus directly in your gas tank. But thanks to a million years of evolutionary fine-tuning, each leaf is a marvel of a machine for turning sunlight into stored energy.

  PART IV

  Flowers

  twenty-one

  Sex in the Garden

  It was about noon on Saturday nearly thirty years ago, and Amy, my best friend since childhood, and her fiancé, John, who had just graduated from medical school the previous day, were getting married at four o’clock. Tomorrow, they would be leaving Washington, D.C., driving a U-Haul to Michigan, where John would start his residency. A congenial cabal of John’s and Amy’s sisters and friends—some busy in the kitchen, others packing boxes in the hallway—were helping to make this happen. The living room furniture was still in place in their garden apartment, but the bedroom was impassable, crowded with bicycles and cross-country skis, stacks of pine shelving, green milk crates, garbage bags filled to rotundity, suitcases, backpacks, framed posters blanketed in bubble wrap, and a craggy mountain of cardboard boxes, all neatly labeled in purple marker in Amy’s cryptic, slanting demi-script. Meanwhile, staff from the party rental company were erecting a tent in the backyard of the building and setting up tables and chairs for seventy-five guests. There would be a potluck dinner, and salad bowls and Pyrex serving dishes and bread baskets—more arriving by the moment—were lined up on the counter of the small kitchen. The cake was in a cooler; the champagne and wine were on ice in the fridge, which was still covered with the artwork of Amy’s third graders. The only thing that was missing was the flowers.

  There was a knock at the front door, and a grinning taxi driver presented Amy with a stack of long, shiny white boxes tied with white satin ribbons. The flowers had arrived, the generous gift of John’s stepmother, Betty, who lived in Honolulu and had brought them with her on the plane. The hotel had agreed to keep the boxes refrigerated. We—the sisters and friends who happened to be in the apartment—gathered in the living room to watch Amy open them. She had no idea what to expect; Betty had solicited no suggestions nor offered any choices. Cue the oohs and aahs: Inside the first boxes were sprays of white orchids, starbursts with thin lines of lavender running down their narrow petals. Other boxes held lovely, traditional Phalaenopsis with rounded, deep purple petals. Delicate yellow blossoms emerged from another set. Then Amy opened one of the three last boxes. Inside were long green stems, each topped with what looked like a red, heart-shaped, plastic plate. At the center of the flower, a fleshy, pink column, longer than my middle finger and about as thick, jutted out at a ninety-degree angle. We stared, and then—pardon the cliché—exploded with laughter. The last two boxes held more of the same.

  Someone said, “They’re anthurium.”

  Amy said, “Well, whatever they are, I’m not having them at my wedding,” and no one disagreed.

  I went to the kitchen to find vases and fill them with water, and by the time I returned to the living room, only the orchids remained to be arranged. Mixed together, they were even more beautiful than they were segregated, a nice metaphor for the coming event.

  It was as high-spirited a wedding as I’d ever been to (the bride wore a tulip-print dress with an eyelet ruffle at the hem and the groom was shod in green tennis shoes) and, happily, did not mean the end of a friendship, as sometimes a marriage and a move do. Recently, on the annual midwinter escape that Amy and I take to Puerto Rico, I mentioned that I was writing about anthurium. Whatever happened, I asked, to those flowers that Betty had brought to her wedding? She laughed, and was surprised she’d never told me the story. Her father had booked a post-wedding suite for them at the Tabard Inn, a small and dignified hotel in downtown Washington. The Tabard is a combination of three old townhouses dating to the 1880s and the rooms are decorated with handhooked rugs, porcelain table lamps, marble-topped dressers, and the like. When she and John walked into the room late that night, there, on the white lace coverlet on the mahogany four-poster bed, amid a shower of glittery red confetti, were the anthurium. Her sisters had spirited them away that afternoon, begged a key from the front desk, and done a little prenuptial decorating. It was a funny moment, Amy said, but even today, she finds the flowers something of a salacious joke and can’t see how anybody could like them.

  I can. I love anthurium.

  I do all my gardening indoors, in the glass-filtered light of a conservatory. No outdoor gardening with dog’s-breath heat and humidity, murderous mosquitoes, and horrible hundred-legged beasties for me. My soil comes, bugless, in plastic bags. Water—into which I carefully measure teaspoons of fertilizer—comes from the spout of a watering can. None of my potted plants are native. All hail from well south of here, and that is my challenge: nurturing a tropical paradise where none has a right to be. Moreover, not only do I live at the wrong latitude, but my conservatory roof faces north. As a result, profusely flowering plants are difficult to sustain, and my domestic jungle is primarily green, rich in textures and shapes but not in color. Slender reeds of Papyrus and the fronds of a Majesty palm reach toward the ceiling. Asparagus ferns hang from pots in frilly abundance. In the western window lives a jade plant with its shiny, plump leaves, a dwarf banana (which, like the Bird-of-Paradise, has never flowered), a classic grandfather cactus, a “pencil cactus” that looks like a tangle of skinny green sticks, and an agave so dangerously spiky, I wear oven mitts when I need to rotate it. A few species offer a bit of leaf color: Maranta (prayer plants), for example, sport pink-veined leaves and Dracaena marginata “Tricolor” have stiletto-like leaves striped from stem to tip in pink, cream, and green. My citrus trees produce tiny white flowers, thanks to the grow lights, but only for a week.

  For real color—and I need it when night falls early and the dark windows seem to suck the heat out of my body and the high spirits out of my heart—I rely on anthurium. There are about a thousand species of the Anthurium genus, and I have varieties whose spathes (the proper name for what looks like a single, giant petal) come in every color on the L’Oreal nail polish display: stoplight red, traffic-cone orange, deep peach, sultry magenta, porn pink (oops, that’s not on the chart), and every hot hue in between. The spadix, that phallic central column, is flashy, too, and can be bicolored in red and pink or gold and cream. Not only are anthurium content with northern light; they retain their vivid colors for weeks and often months.

  Amy is not the only one who does not appreciate anthurium. Ted is not a fan. When the plants are all in bloom—and I usually have about a dozen of them—he says the conservatory looks like a bordello with the customers caught in flagrante delicto. I have seen how they make guests uncomfortable. Having a dinner party in the conservatory among anthurium is not like picnicking in a field of sweet meadow flowers. Not unless the Marquis de Sade happens to be lounging en déshabillé on your picnic blanket.

  But, of course, even the white daisies, pink clover, ivory Queen Anne’s lace, and lavender lupines in the meadow are all about sex. Their pretty petals and delicate scents are the come-hither signal to insects, an invitation to sample the sweet rewards inside. On the way to sip the nectar tucked away at the
base of the flower, an insect—the only real innocent on the scene—picks up pollen that will fall off inside the next flower it visits. Ironically, when it comes to anthurium, the anatomical part that makes us blush is just a sturdy stem that hosts the plant’s flowers. Those flowers are so minute that you need a magnifying glass to see them. Except to human eyes, the anthurium is actually a model of floral modesty.

  Anthurium do not grow in Europe, although other spadix-sporting aroids (as members of the Arum genus are called) do. The Cuckoo Pint (Arum maculatum) grows in temperate northern Europe. Pint is a shortening of pintle, a medieval word for penis. Dracunculus vulgaris, which grows in the eastern Mediterranean, features a two-foot-long dark purple spadix. Nonetheless, these species inspired no medieval or Renaissance Europeans to suppose that flowers had anything to do with procreation. (Theophrastus’s report of North Africans shaking the dust of male date palms over female palms had slipped from common knowledge.) After the fall of Rome in the fifth century, the keepers of knowledge, both sacred and profane, became the clergy, and no group was less likely to interest itself in the sexuality of plants. By the medieval era, as the veneration of Mary and virginity grew, writers and artists linked her with a host of flowers. Marigolds, roses, rose of Sharon, violets, irises, orange tree blossoms, and many other flowers decorated the background of drawings and paintings that featured her. A sacred space featuring a statue of the Virgin surrounded by these flowers was known as a “Mary Garden.” The white lily became Mary’s signature flower in the twelfth century when the angel Gabriel was first pictured offering them to her at the Annunciation. Naturally, no one living in the era could have imagined that flowers, those inspiring reminders from God of the goodness of chastity, are actually an invitation to an orgy.