Seeds of Hope

by Jane Goodall

  “Methuselah,” the male date palm that emerged triumphantly after a long, long sleep.(CREDIT: GUY EISNER)

  I was absolutely fascinated by this story of Methuselah and, wanting to learn more, contacted Dr. Sarah Sallon, of Hadassah Medical Organization in Jerusalem, who devised the project, along with Dr. Elaine Solowey, from Kibbutz Ketura, a specialist in growing plants for arid environments, who has been overseeing Methuselah’s progress. By good fortune Sarah was about to visit a friend of hers who lives near Bournemouth, so she was able to pop in and visit. She told me that Methuselah had just flowered—a male! She hopes the archaeologists will let her have more seeds of the same age in the hope that one might be a female. How amazing would that be!

  Although Methuselah is the oldest seed to have been woken from a long sleep, there are other very old seeds that have germinated. Such as the single lotus seed (Nelumbo nucifera) found in China in an ancient lake bed and carbon-dated at about 1,300 years. Another seed, one from the flowering perennial Canna compacta, carbon-dated at about 600 years old, had survived for goodness knows how long in a walnut shell that was used for a ceremonial rattle.

  And then there is the delightful story of some seeds collected in China in 1793 that were housed in the British Museum. These seeds, at least 147 years old, started to germinate in 1940 when they were accidentally “watered” by a hose used to extinguish a fire!

  Bringing “Dead” Seeds Back to Life?

  A miracle of a different sort took place when a couple of seeds of an extinct plant, Cylindrocline lorencei, a beautiful flowering shrub, were—quite literally—brought back from the dead. In 1980 only one individual plant remained, growing in the Plaine Champagne area of Mauritius Island. And then this last survivor died also. The only hope for saving the species lay in a few seeds that had been collected by botanist Jean-Yves Lesouëf in 1980, and stored in Brest Botanic Gardens in France. Unfortunately, however, all attempts to germinate these seeds had failed.

  But plant people do not easily give up. Using new techniques, horticulturists found that small clusters of cells in the embryo tissue of just one or two of the seeds were still alive. Eventually, painstakingly, three clones were produced. And finally, in 2003, nine years from the beginning of their efforts, those three clones flowered—and produced seeds!

  When I visited Kew, Carlos showed me their plant, donated by the botanical gardens in Brest, derived from one of those original clones. As I looked at it, I felt a sense of awe. What an example of the determination and perseverance of the horticulturists—and thank goodness for the intrepid botanists who have collected seeds around the world and, in so many cases, saved precious life-forms from extinction. Plans are now under way to return Cylindrocline lorencei to its faraway home on Mauritius.

  Cylindrocline lorencei at Kew. At one time all that was left of this flowering plant were just a few seeds, and all attempts to get these remaining seeds to germinate failed. This is one of three clones that a team of botanists was able to create from a few live cells of the seemingly “dead” seeds. If this science fiction feat hadn’t been successful, this plant would now be officially extinct. (CREDIT: © COPYRIGHT THE BOARD OF TRUSTEES OF THE ROYAL BOTANIC GARDENS, KEW)

  While I was still gazing at this plant, Carlos smiled and said, “This is as if tomorrow we were to find a frozen mammoth in Siberia, and even though the mammoth is dead, a few cells in the bone marrow were still alive and from it a whole mammoth could be cloned.”

  As I was finishing writing this book, I heard how Svetlana Yashina and her team of Russian scientists regenerated a plant using fruit tissue that had been buried in the Siberian permafrost for over thirty thousand years! This plant miraculously given new life is a species of campion (Silene). And, most exciting of all, after a year had passed, this lovely flowering plant showed that it was fertile, able to bear viable seeds.

  It was found in a stash of plants and fruit in the burrow of an Ice Age squirrel 125 feet below the present surface of the permafrost. The team also discovered bones from woolly rhinoceros, deer, and bison, as well as other large mammals, in that same ice layer. The researchers claim that their success with S. stenophylla could help us discover ways to resurrect animals from the Ice Age. “If we are lucky, we can find some frozen squirrel tissue,” one of the lead researchers was quoted as saying, “and this path could lead us all the way to mammoth.” Carlos’s remark might be uncannily prophetic.

  Seed Banks: Arks for Plants

  The very fact that plants have found such remarkable mechanisms for helping to ensure their future is indeed fortunate in this time of environmental destruction caused by our own species. If we can store seeds in such a way as to enable them to grow at a later date, we may be able to save plant species on the brink of extinction and restore them to nature when we have ensured favorable conditions.

  The world’s largest wild-plant seed bank is the Millennium Seed Bank Partnership, established at Kew’s sister site at Wakehurst Place in West Sussex. In August 2009, I visited this remarkable project. I was taken around by Kew’s International Project Coordinator, Dr. Tim Pearce, and we were accompanied by the photographer and seed expert Wolfgang Stuppy, who had given me that glorious book about seeds.

  At the time I visited, Tim told me they were storing, for safekeeping, over one billion seeds from thousands of species of plants, including over 95 percent of the United Kingdom’s flora. Later, when I checked back in 2013, Kew and its partner institutions (from more than eighty countries) had banked seeds from at least 10 percent of the wild plant species of the world. By 2020 this should increase to 25 percent, providing funding support continues.

  When we went into the actual storage room—“the Bank”—I had the strangest sensation. There I was in a huge room not unlike the vaults of a bank save that the temperature is minus 20 degrees centigrade (minus 4 degrees Fahrenheit), surrounded by millions and millions of sleeping seeds from about thirty thousand species of plants from all over the world. They are kept in small, sealed glass canisters that line the room, labeled with numbers and dates and other important information. Each canister is in its own little locker, into which you can peer through a glass panel.

  It was not at all like walking through the Herbarium, for there I was closeted with dead plants; in the seed bank I was sharing the space with thousands of sleeping beauties—awaiting not a kiss from a prince but a thawing and watering. Then would come the unfurling and the great magic as the DNA of each little seed determined the nature of the plant to be.

  “It is a strange thought,” said Tim, “that this is the most biodiverse place on the whole planet.” Indeed, nowhere else can come anywhere close to representing more than thirty thousand different plant species—and in such a small space.

  By the time I left, I had a good idea about the work that goes on in this seed bank, the largest international conservation project for wild plants in the world. The seeds come in almost daily by DHL—sometimes as many as a hundred samples at once. Each sample must be labeled and accessioned into the Millennium Seed Bank collections. All seeds have been sent voluntarily to the seed bank, mostly by botanical gardens, in a global effort to safeguard the future of the diversity of plant species on Planet Earth. Some need a great deal of cleaning, while others, sent by trained collectors, are more or less ready for the next stage.

  Next, on to the “Dry Room,” where all water is extracted, and where all sorts of technology are brought into service. There are machines that replicate winnowing, whirling the seeds around, blowing air through them, and shaking them. Sometimes, though, it is necessary to clean delicate seeds by hand to prevent them from being damaged by machinery. After this, a sample of the seeds is X-rayed, and I was able to see how many of those from a recent acquisition were infested with insect larvae. Tim told me they were especially proud of this X-ray machine, since most seed banks cannot afford such equipment. (Indeed, there are too many hospitals in the developing world that have no X-ray machines—but the one at the
seed bank is too small to use on people.)

  An important goal of this seed bank is to help improve the quality of collections around the world, and one way of accomplishing this is to share technology. “Today,” Tim told me, “there is a gadget that can be used in the field to enable collectors to determine the level of maturity of a seed—when a fruit is ready to be eaten or a seedpod is about to explode.” It is obviously important to harvest seeds at the optimum point of maturity. And it is also necessary to collect seeds from different parts of a plant’s range to obtain maximum genetic diversity.

  “And of course,” Tim pointed out, “it is extremely important that the collector notes down as much information as possible and sends it with the seeds: the exact location, other species growing nearby, temperature, humidity, altitude, and so on.” I remembered reading how that great plant hunter David Douglas lost the field notebook in which he had kept meticulous records of all the plants he collected in California. It happened when his canoe capsized and was destroyed on rocks—one of the most disastrous of his many accidents, for all that information was lost forever.

  Growth by Fire

  We now know that some seeds actually need fire in order to germinate—just one more example of the fascinating interrelationships that we find in the natural world. The cones of the lodgepole pine are glued shut by a strong resin, which melts in the heat of a wildfire so that the cone can burst open. Thus the seeds are not dispersed until the conditions are right for the growth of seedlings—when there is diminished litter on the forest floor, giving them space and more light.

  Erica verticillata is a beautiful South African plant with stunning magenta conical flowers that uses fire in a different way. Originally it grew on the Cape Flats, but by the 1950s it was listed as extinct. And then, in 1984, a botanist working in the herbarium of the Kirstenbosch National Botanical Garden in Cape Town saw the pressed specimens there and wondered whether, perhaps, it might still exist. Soon his quest to find the lovely Erica became a personal obsession. Eventually he found four different individuals, all in different locations—one was actually growing at Kew and another was right under his nose in the Kirstenbosch Garden!

  It had been relatively easy to propagate new plants from cuttings from each of these four survivors, but although they produced seeds, the seeds did not grow. Victoria Wilman, a botanist who helped with the plant’s revival, told me that it had taken a while to figure out what was necessary to germinate the seeds. They found that throughout the historic range of Erica, periodic fires had occurred naturally every five years or so. And not only did these fires sweep through the thick vegetation, leaving open areas that were then colonized by new plants, but horticulturists found that chemicals in the smoke, coupled with the autumn change in temperature between day and night, stimulated Erica seed germination as the winter rains began.

  To mimic this situation, material from the plant itself, including old flower heads and green leaves, is ignited and the smoke is collected and allowed to settle. This concentrated smoke extract is then dissolved into the water, which is used for germinating Erica seeds. The scientists at Kew told me that they get some of it each year.

  The efforts of the South African team have been so successful that Erica has been successfully reintroduced into the wild—the seeds, dispersed by the wind, are viable, and plants are appearing all over the place. And this very beautiful plant is now being grown in gardens.

  This is what I love about so many of the horticulturists of the world—the way they are willing to watch and learn from the plants themselves. The innovative experiments they devise, the patience they demonstrate. And they understand the interdependence of life-forms, and realize the need to study the plants in their natural environment. But despite all their scientifically based investigations, some discoveries are made by accident.

  As was the case with another endangered South African plant, Serruria florida, charmingly named “Blushing Bride.” At one time it was listed as extinct, but then one or more populations were discovered between 1891 and 1914. In 1943 the only known wild plants, in the Franschhoek Valley, were destroyed by a bush fire. Three years later, to botanists’ amazement, sixty plants were thriving there. The conclusion that fire was necessary for germination seems, in hindsight, obvious. But at the time such an idea seemed inconceivable, and the area with the precious plants was rigorously protected from fire. The plants decreased in number. Undergrowth was cleared to prevent competition from other plants and give any other seeds a chance to grow. To no avail.

  Then an accidental fire again swept through the area—and massive germination took place thereafter. At which point the botanists finally realized, to their amazement, that fire was actually necessary for the propagation of the Blushing Bride—as it is, we now know, for all fynbos species. It is the heating of the soil as the fire sweeps across the ground that breaks seed dormancy.

  War, the Tower of London, and a Red Leather Wallet

  His understanding about the role of fire was helpful to Dr. Matt Daws when he was put in charge of an exciting project: to try to germinate some old seeds that had an extraordinary history. They had been collected in Cape Town by Jan Teerlink, a Dutch merchant, at the time of the Napoleonic Wars in the early 1800s. Teerlink’s vessel had been captured by the British navy while sailing back from Cape Town.

  Everything, including a very large red leather wallet, was seized. The wallet was handed to the Tower of London and eventually ended up in the British National Archives, where, in 2004, it was found by Roelof van Gelder, a visiting scholar from the Netherlands. Inside the wallet he found forty packets of seeds, most of which were labeled with scientific names, but including some that had not been identified. Carbon dating showed they were two hundred years old.

  What an incredible find: thirty-two species of plants were represented by those centuries-old seeds, and a few of each were sent to the Millennium Seed Bank. There, Matt Daws first exposed the seeds to smoke. Of twenty-five seeds from one legume, sixteen sprouted. There were eight seeds of another legume, and one of these sprouted. There were just two seeds of Acacia type—one had been damaged by insects, but the other sprouted. Two years after germination there were two tiny shrubs, each about four inches high, and a waist-high acacia.

  “If seed can survive that long in poor conditions,” Matt Daws told the Royal Botanic Gardens, Kew, “then that’s good news for those in the Millennium Seed Bank stored under ideal conditions.”

  A Story of Two Humble Grasses

  I want to give an example of a simple European field plant that would have quietly faded into extinction—indeed it was deemed extinct for decades—if not for the existence of seed banks as well as the passion of one botanist.

  In the first half of the nineteenth century in two different parts of Europe, two genetically different species of brome were recorded for the first time. The interrupted brome (Bromus interruptus) appeared in England, and the more picturesquely named brome of the Ardennes (Bromus bromoideus) in Belgium. Each of these grass species had, it seemed, evolved quite independently of the other as a result of sudden major genetic changes. Both were growing in the countryside, where they shared the fields and meadows peaceably with other grasses, including wheat, barley, and rye. But unlike those cousins, the two new bromes were of no use as human food.

  Which is presumably why, some 150 years after their discovery, both of the new bromes had become extinct in the wild. For farming methods changed after World War II, and farmers treated their fields with the new agricultural poisons to make the land more productive (in the short term) and to make the farmers themselves more money, and thus the bromes gradually disappeared with no one noticing. By the time people did notice, the bromes were officially listed as “extinct.”

  Before the bromes were deemed extinct, back in the early sixties, I was working for my PhD at Cambridge University. I used to take a little tent and camp, on weekends, at the edge of some field in the country, brightened by the red of th
e poppies that grew there. I remember lying in hidden places in the hay fields and watching the skylarks as they flew higher and ever higher until they were the tiniest of black specks against the deep blue of the summer sky. And still their song could be heard, that glorious spilling of joyous music. I would recite to myself in a quiet voice a few lines from Shelley’s “Ode to a Skylark,” because poetry was so important to me at that time in my life:

  Hail to thee, blithe Spirit!

  Bird thou never wert—

  That from Heaven or near it

  Pourest thy full heart

  In profuse strains of unpremeditated art.

  The bromes might have been lost to us forever but for the fact that botanists not only care about the showy, exotic plants but are also interested in the smallest and most humble of them.

  In 2005, David Aplin, a British botanist who was working in the National Botanic Garden of Belgium, had to give a talk at a conference on plant conservation and wanted to give some examples of Belgian species that had become extinct. He selected the brome of the Ardennes, which had been gone for about seventy years, and began to research its history.

  After an exhaustive search he found that even those that had been grown in various botanical gardens had vanished. And then by accident he found a handful of seeds of the brome hidden away in a drawer in the seed bank where he worked. I asked him how he’d felt, and he said he’d experienced a real sense of awe as he looked at them, for they were almost certainly the last seeds of that plant anywhere in the world.