When it comes to plants, it takes a lot to astonish someone like Elaine Solowey. The California-born horticulturist has spent decades living and working in the hot, arid expanse of Israel’s remote Arava Valley – one of the most inhospitable environments in the world, replete with temperature extremes, saline soil and low rainfall. At Kibbutz Ketura, near the southern end of the valley, Solowey spends much of her time tending extensive fruit orchards and other crops. She establishes healthy soil where she can, a slow and painstaking process in such an eroded landscape. In fact, as an expert in desert agriculture with an affinity for botanical challenges, Solowey often has any number of experiments on the go, mostly with wild plant varieties. She wants to see what might thrive, with a bit of coaxing, in a place like this. Already she has grown evergreen neem trees from India, and rare Tibetan loquats. She has even managed to sprout the near-threatened Boswellia sacra, famed for its production of frankincense resin and an exasperating reluctance to germinate. In short, Solowey has spent more than forty years revitalising the desert by inches – reclaiming the land, as she puts it, ‘from the dust, the heat and the salt’. Under her care, she has seen plants defy remarkable odds. She is no stranger to the difficult, the unlikely, and even the downright improbable. But one time, she was completely thrown for a loop by a single seed.
In January 2005, a scientist named Sarah Sallon arrived at Kibbutz Ketura with a very unusual delivery. Sallon is the director of the Louis L. Borick Natural Medicine Research Center at the Hadassah Hospital Ein Kerem in Jerusalem, and she had worked with Solowey on a few projects relating to medicinal plants over the years. Now here she was with a handful of unusually large date palm seeds that looked like they’d seen better days. Sallon explained that these were no ordinary seeds. They had been discovered during an excavation at Masada, one of the most historically significant archaeological sites in Israel. And they were nearly 2000 years old. Given their age and the location where they’d been found, it was likely they were seeds of the long-extinct Judean date palm.
Sallon had convinced archaeologists and archaeobotanists at Bar-Ilan University in Jerusalem to part with a few seeds from their Masada collection so she could give them to Solowey, who knew a thing or two about date palms. Date crops of the commercial Medjool variety help generate income for Kibbutz Ketura, so Solowey had grown and harvested many in her time. Solowey concluded that Sallon had brought these seeds as an interesting souvenir. Sallon, however, had something different in mind. She wanted Solowey to plant them.
‘You want me to do what?’ Solowey had asked, incredulously.
‘I want you to try to sprout these seeds,’ Sallon repeated, explaining she had a gut feeling that some of these seeds were still alive.
Solowey was unconvinced. They were talking about a time span of nearly two millennia, after all. But Sallon was persuasive. Solowey eventually agreed to help, promising only to do her best. Still, she couldn’t imagine that seeds this old could be any more capable of sprouting a date palm than a shard of pottery found at the same site. It was harder still to imagine what it would mean to reach into the depths of botanical extinction and bring back, of all things, a Judean date tree.
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Just before Passover in 70 CE, as Jerusalem’s residents prepared feasts and the streets swelled with pilgrims, the Romans attacked. For three months, the walled city was surrounded and under siege. It’s said that the Roman general Titus ordered every tree within 15 kilometres cut down for the construction of a siege wall in order cut off supplies, as well as any means of escape. Many nearby crops were destroyed and whatever remained could not be reached. No seeds could be sown, no crops tended – nothing grew, nothing was harvested. Within the city, the situation became increasingly desperate. Fight, submit or starve? No one could agree. Infighting led, catastrophically in one instance, to the burning of most of the city’s food stores. By August, the Romans had breached Jerusalem’s famed walls and, with brutal finality, burned the Second Temple. Of the many thousands of Judeans who died during the siege, most succumbed to starvation. It was, in the end, one of the deadliest summers in antiquity.
In Rome, they celebrated. A new coin was minted to commemorate the occasion, with the insignia ‘JUDAEA CAPTA’ (‘Judea captured’) encircling an image of a woman mourning beneath a date palm, the latter being a well-known symbol of Judea. But Judea had not been entirely conquered, not quite yet. Remarkably, some rebels had escaped and found their way to the fortress of Masada.
Perched high on an isolated plateau between the harsh expanse of the Judean desert and the lifeless shallows of the Dead Sea, Masada was a fierce marriage of geology and architecture set within a hostile wilderness. The plateau on which it was built rises an imposing 450 metres, within view of the Dead Sea’s salt-crusted shoreline. It was defended by 1300 metres of high stone walls, beyond which jagged cliffs plunged into barren ravines. In the first century CE it was connected to the world by only a few thin, treacherous paths. To those fleeing here, it must have seemed as though they’d reached the end of the world. And in a sense, they had. It was only possible to shelter and survive in a place like this if you were well supplied. Fortunately for the rebels, Masada was kitted out nicely.
When King Herod the Great ordered construction of the fortress to begin in 35 BCE, he had been hedging his bets. As the Roman-appointed king of Judea, he was neither trusted nor accepted by the Jewish people. With enemies everywhere, a remote desert fortress seemed like a good backup plan – especially a stronghold where Herod could live comfortably with family and friends in the event of a drawn-out insurrection. And so it was that, in addition to the defensive walls and towers, Masada’s original builders had constructed ample living quarters, Roman baths with a central furnace, an administrative building, and an opulent three-tiered palace descending the northern cliff.
The ‘Hanging Palace’ was an extravagance, of course. Masada’s true value lay in its storage facilities. An elaborate network of channels and small dams had been built to catch both stormwater and winter floodwaters, both of which were priceless. The water was collected in a series of massive cisterns, some with a capacity of 4000 litres, that had been dug into the rocky foundation. It was said to be so effective that a single day’s rain could provide water for a thousand people for at least two years.
Masada also possessed a large complex of storerooms, many of which were used for food storage. These, too, were well designed and benefited from the uniquely dry and salty environment afforded by Masada’s proximity to both the Judean desert and the Dead Sea. As the story goes, when the rebels first arrived, they found perfectly preserved dates and other foodstuffs left by those who had resided there in the final stages of construction nearly a century earlier. According to the scribe Josephus, who would chronicle what came to pass at Masada, the rebel population grew to 967 in the two years immediately following the fall of Jerusalem: supplies were sorely needed.
As the archaeologist Jodi Magness describes in her book Masada: From Jewish Revolt to Modern Myth, despite its impressive infrastructure, daily life at the fortress would have been harsh, and a great deal of energy would have been dedicated to procuring, storing and preparing food. The Judeans built and tended gardens at Masada but even small-scale agriculture must have been challenging on that dusty, sun-bleached mesa. Other supplies were not so far away – Date palms grew surprisingly well near the otherwise barren coast of the Dead Sea, and the variety of dates they produced were nutritious, amenable to storage and very nice to eat, and a little further up the Jordan Valley where the land was more fertile, there was barley, wheat, legumes and figs. Yet it would have been increasingly treacherous to venture from the relative safety of Masada as the Romans drew ever closer.
In the centuries leading up to the rebels’ final days at Masada, dates had become one of the most important crops in Judea. This wasn’t so unusual. At the time, date palms were grown across the entire region extending from North Africa up through the Middle East. Prized for their ability to grow in hot, dry environments, date palms were cultivated in Egypt, on the island of Cyprus, and in Ionia, which is now the western coast of present-day Turkey. Date palm groves also skirted the northern curve of the Arabian Sea and could be found as far east as the Indus Valley, in what is now southern Pakistan.
Dates, in their numerous varieties, were an important source of nutrients. They were eaten fresh and dried, smashed into paste, and used to make date cakes and date porridge, date honey and date wine. The archaeological record is filled with such recipes and serving suggestions. The rest of the tree was highly valued, too, and used in its entirety. The trunks were used in the construction of buildings and boats, as well as in carpentry and fencing. Date palm logs fuelled fires for warmth and cooking, and bronzesmiths were sometimes known to use date stones in lieu of charcoal. The fronds were used as brooms and fans, and for thatching roofs. The long fibrous leaflets were woven into ropes, fish nets, baskets and sleeping mats. The list goes on. Indeed, in the first century BCE, the Greek geographer Strabo wrote of an old Persian song that listed 360 uses for date palms.
An ancient poem titled The Assyrian Tree, which originated in Parthia, now part of Iran, is told in part from a palm tree’s perspective as she lists her many attributes to a foe, a rather unimpressed goat. The scene takes place in Xwanirah, which at the time referred to the central continent in the known world.
In Xwanirah land there is no tree of my build.
For the king eats of me when I newly bear fruit.
I am ships’ planking; I am the mast for sails.
They make brooms of me which put in order house and home.
They make pestles of me which pound barley and rice.
They make fans of me for the fires.
I am shoes for farmers; I am sandals for the barefoot …
In summer I am shade for the heads of governors.
I am milk for farmers, honey for noblemen.
They make boxes of me for medicines.
They carry (these) province to province, physician to physician.
I am a nest for little birds, shade for wanderers.
I cast down my stones; they grow on fresh ground.
If people allow, so they do not harm me, my top will be green until the day eternal.
And those persons who lack bread and wine eat fruit from me till they become filled.
Date palms, it seems, were central to the daily functioning of a vast swathe of the ancient world. Perhaps unsurprisingly, they achieved widespread cultural status. For thousands of years, the date palm appeared in mythology and sacred texts where it was, by turn, a symbol of prosperity, fertility and immortality. A date palm represented the Mesopotamian goddess Mylitta and her Phoenician counterpart Astarte. Egyptians decorated murals and columns with date palms to signify life and longevity. Indeed, the hieroglyphic for ‘year’ was an image of a single date palm branch. According to some versions of a Greek legend, the gods Artemis and Apollo were born beneath the boughs of a date tree.
And yet, not all date palms were considered equal. Of the numerous varieties, those that grew in Judea – in what is today southern Israel – were the most popular. The dates they produced were renowned for their good flavour and large size, with some reaching 11 centimetres in length. Judean dates made better honey and better wine than did other dates. The famed Greek physician Hippocrates praised Judean dates for their medicinal qualities. So, too, did the Roman physician Galen. Even the Babylonian Talmud mentions a date variety named ‘Taali’, which was cultivated in Babylon and Judea. These dates were said to heal, strengthen and purge the body.
Perhaps the real key to the popularity of Judean dates was their long shelf life, which provided a critical economic advantage. According to records from the time, dates grown in Egypt and Cyprus were soft and sweet when eaten fresh but did not store well, often becoming rotten when transported. The slightly drier Judean dates not only tasted better, they lasted. They could be stored for months on end and endured long-haul passage – remarkable considering the slow, halting pace of ancient international shipping at that time. This meant the dates could be transported further down the Nile to Cairo and Thebes, as well as to Anatolia (Turkey), mainland Greece and as far as Rome itself.
Intriguingly, Judean dates primarily grew in three specific areas in the Jordan Valley: Ein Gedi on the western coast of the Dead Sea, Jericho near the northern shore, and Beit She’an, which lies further north towards the Sea of Galilee. Ancient geographers, physicians and botanists noticed that the salty soil of the valley and the Dead Sea environment most likely had something to do with it. There were attempts to grow this cultivar elsewhere, but the plants just didn’t take. With trees producing a bounty of dates every growing season, grove owners prospered and planted more and larger groves. According to Strabo, groves in the vicinity of Jericho extended over 100 stadia (17 kilometres). In fact, Jericho had such an abundance of these crops that it was often referred to as the City of Dates or the City of Palms.
Such a source of wealth did not escape the Romans’ attention, of course, and while control of the date trade was not their primary reason for first conquering Judea, it was most certainly a significant benefit. Access to the delicacy itself didn’t hurt either. Once Judea was under Roman rule, its dates were regularly served at the emperor’s table. In 35 BCE, while the first bricks were being laid at Masada, the Roman politician Mark Antony gifted Jericho – plantations and all – to his lover Cleopatra VII of Egypt. Cleopatra, ever the shrewd strategist, leased it back to King Herod in return for a hefty cut of Jericho’s profits. The date trees were far more than a valuable commodity to the Judeans, however. Only dates grown in Jericho, Ein Gedi and elsewhere in the Jordan Valley were carried to the temples and offered reverently as First Fruits. Date palm leaves, which came to symbolise peace and sanctity, were used in holy rituals and featured during religious observances and festivals. And ultimately, at a time when siege warfare was commonplace, Judean dates offered a chance for survival.
By the first century CE, the Roman army, known more for its twin talents of engineering and destruction than its horticultural nous, saw little point in seizing the vast and valuable date groves of Judea, and instead chose to decimate this central feature of the region’s economy. Date palms were burned in their thousands. Some groves were spared but few people remained who knew how to tend them – most had been exiled or killed.
Certainly, cultivating dates requires a lot of work and specialised knowledge. Date palms are flowering plants – they reproduce sexually. The overwhelming majority of flowering plants have bisexual flowers, meaning they possess both male and female reproductive structures in the same flower. A rose, for example, has a pollen-producing male structure called a stamen, as well as a female pistil that produces ovules. By contrast, around 10 per cent of flowering plants have uni-sexual flowers, which are either male or female. Some of these are monoecious, which means they produce distinct male and female flowers that both grow on the same individual plant. Corn, which is a monoecious flowering plant, produces both male and female flowers on the same stalk. The rest are dioecious plants, where the male and female flowers grow on entirely separate individual plants. Around 6 per cent of all flowering plants are dioecious, palm trees among them. Thus, any given palm tree, including any given date palm tree, is either male or female. Only the female trees produce fruit.
Ancient cultivators learned how to determine which trees were male and which were female. They needed to know when and how to collect pollen from male flowers and use it to manually fertilise female flowers, and when to harvest the dates. Moreover, while date trees can be grown from seeds, propagation by planting a palm’s early offshoots was a more productive and common practice. So farmers needed to know which offshoots were ready, how to remove them without killing them, which conditions were best for planting, and how to tend the growing trees. This knowledge likely took centuries to amass and would have been passed down within families and in local communities.
After the fall of Masada around 74 CE, Judean dates were still harvested for a few hundred years, but nowhere near previous levels – these were just echoes of what had come before. And as the region endured further waves of conquests, knowledge of Judean date palm farming faded away. By the 11th century, the ancient Judean cultivar was most likely extinct. Historical accounts from the 19th century reveal that date groves in Israel consisted mainly of wild trees or low-quality seedlings and the fruit was described subsequently as ‘bad’ and ‘not fit for ordinary consumption’.
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Israeli archaeologist Yigael Yadin and his team arrived at Masada in the early 1960s and found a scene of devastation preserved in dust and salt and ash. Masada had certainly burned, though not all of it. Among the rubble and the charred debris, the scientists found broken pottery and shields, arrows, silver shekels (coins) and remnants of clothing. They even found scrolls, religious texts mostly, along with papyri on which Latin had been scrawled. Among them was a fragment of Genesis in Hebrew and, more banal, a payslip belonging to a Roman soldier named Gaius Messius; it appears he hadn’t earned much for his services. They found bones, too, and ash – so much ash. And in one room near the Northern Palace, beneath a 60-centimetrethick layer of ash, they found ‘a big heap of whole dates’.
Along with the many other things found at Masada, the dates and date seeds were meticulously catalogued, transported and stored. By the time Sarah Sallon showed up in 2005, they’d been sitting in room-temperature storage for four decades. The archaeologists at Bar-Ilan University had taken some convincing, but at last, with their hard-won permission, Sallon picked the dates she believed had the best chance of germinating. This was mainly an exercise in intuition: as is the case with seeds in general, save for those with obvious physical damage, it was not possible to tell which ones were still alive just by looking at them.
In the days following Sallon’s intriguing visit to Kibbutz Ketura, Elaine Solowey considered the unusual task before her. ‘It took me a while to think of how I was going to do it,’ she tells me.
It didn’t matter whether she believed the seeds were alive or not. She had to treat them as though they were. She reasoned that sudden hydration might be a shock after two millennia of dormancy, so she began gently, hydrating the seeds very gradually. Next, she added a plant hormone called gibberellic acid, which is sometimes used to ‘jump-start’ seeds. Then, after adding a bit of fertiliser, she planted each seed in its own carefully labelled pot and quarantined them in a greenhouse. Then she locked the door and got on with other things.
Solowey checked in from time to time, of course, but the pots just sat there like a collection of unremarkable black plastic containers full of soil. Nothing to write home about, and certainly nothing to write to Sallon about. But one cool morning in mid-March 2005, Solowey entered the greenhouse and stopped in her tracks. In one container, the pale tip of a palm tree seedling was poking out of the dark soil.
‘I was completely astonished!’ she recalls. She had to remind herself of all the precautions she’d taken, ticking them off as assurances that what she was seeing was real: ‘It was new pots, new potting soil, new irrigation and it was locked up, so I knew it wasn’t contaminated.’
It was real. This seed had been alive for almost 2000 years, just waiting for the right conditions. And yet, something was wrong. Healthy date palm shoots are usually green, but this shoot tip was so pale it was almost white. In a heartbeat, Solowey’s excitement evaporated. Her efforts had clearly activated the seed’s ancient germination mechanisms, but what if not everything was working as it should? A lot can go wrong in two millennia. A shoot had pushed upwards and broken the surface of the soil, but Solowey knew that sometimes even perilously damaged systems can work for a little while, until they don’t. She was worried the seed had lost the ability to make chlorophyll, which meant it would be unable to use photosynthesis to turn sunlight into essential carbohydrates for growth. Every now and then this happens with seeds, even new ones. It’s basically a death sentence for the plant, says Solowey.
Then, as if some drowsy primordial cog had been nudged into motion, the shoot slowly began to make chlorophyll and became greener. Solowey didn’t breathe a word of it until June. In part, she wanted to make sure the seedling would truly keep growing, but mostly, she confesses, she still didn’t realise it was all that important. She only mentioned it in passing to Sallon one day after they’d been speaking about something else entirely.
‘I happened to say to Sarah, “Oh, by the way, one of your seeds came up.”’
‘What?!’ Sallon had blurted. ‘One of the seeds came up?’
The next thing Solowey knew, she was on CNN.
As the date palm grew at Kibbutz Ketura, surely and steadily, so too did the anticipation. Could this palm produce dates? Six years later, Sallon and Solowey would have their first clue.
When a date palm is mature enough, it produces clusters of flowers that grow along closely crowded branchlets. At first, these clusters emerge inside a protective sheath called a spathe. In the early days of flowering, the spathes appear like large papery pods, arising high up the trunk, shaded by the tree’s expansive leaves. In time, each spathe dries and splits open to reveal its floral bounty. Although there are distinctive differences between the male and female flowers – the presence of pollen sacs in the male flower, for example, and the more compressed structure of the female – you don’t need to wait for the blooming to find out what you have. The shape of the spathe itself gives everything away, says Solowey. The male spathe is shorter and broader, the female spathe is longer and flatter.
When the Judean palm produced its first spathe, Solowey had the answer: ‘I knew immediately it was a boy.’ With a nod to the long-lived patriarch in the Bible’s Book of Genesis, Solowey and Sallon named him Methuselah. Being a male date palm, Methuselah could not produce dates, but it was hoped that he could, like his eponym, become a father. All they had to do now was find a female.
Sallon paid another visit to Bar-Ilan University and also contacted archaeologists at the Hebrew University of Jerusalem. She returned with thirty-two ancient date palm seeds that had passed her scrutiny. Not all were from Masada. There are other historical sites where date palm seeds have been found, and Sallon wanted to give these a try as well. Some were from the Qumran Caves, where the Dead Sea Scrolls had been discovered. Others had been found in caves at Wadi Makukh and Wadi Qelt, just north of the Dead Sea, near Jericho.
Solowey planted all of them and, to her delight, six new shoots came up. As the years passed, they grew and flowered: four males, two females, ancient date palms all. Radiocarbon dating of the seed shell fragments revealed the youngest among them was from the first or second century CE at the latest. The two oldest were dated to sometime between the first and fourth centuries BCE. In a stroke of luck that verges on the poetic, the oldest of them all turned out to be female. Her seed had been found at Wadi Makukh, and she was estimated to be around 175 years older than Methuselah. They named her Hannah.
When Hannah was old enough, Solowey collected pollen from Methuselah and brushed it gently over some of Hannah’s flowers. Just a small cluster, mind you. It was far too soon to pollinate the whole tree because Hannah was still relatively young and Solowey did not want to cause her too much stress. It was spring then – April of 2020 – and the world was in the midst of the pernicious first wave of the COVID-19 pandemic. Israel, like many other countries, was in lockdown. Days passed like months, months like years. Although the globe was in turmoil, the tough landscape of the Arava Valley seemed to enclose Kibbutz Ketura like a spathe. Gatherings were put on hold, not an easy measure given that a kibbutz is meant to be communal. But life otherwise continued: crops were tended, date palms grew. It is a remarkable thing to realise that this is not the first pandemic to occur in the lifetimes of these ancient date palms – it isn’t even the eighth.
As summer edged towards autumn, Hannah became a mother and Methuselah a father. In all, Hannah had produced 111 dates that collectively resembled a cluster of large amber jewels. And so it was on a warm September morning, when the dates were wrinkled with ripeness, that the first harvest of Judean dates in many centuries took place. Sallon, Solowey, members of the kibbutz and others gathered as Solowey’s husband Michael recited Hebrew blessings over the large platter of dates – a traditional harvest blessing for the fruit tree and the Shehecheyanu blessing to offer gratitude for new and unusual experiences.
And then, the first taste. They were semi-dry, just as the ancient records had suggested, a quality that likely afforded their legendary shelf life. Solowey describes them as having a nice honey aftertaste. ‘It’s a good thing it tasted good, because how would I have explained it otherwise?’ she laughs as she imagines the predicament. ‘“Oh, we have these ancient dates, but they’re terrible!”’
It’s worth pausing to consider how astounding it is that these seeds survived as long as they did, to not only germinate but also to grow and thrive and produce a new generation. Now that she knows what is possible, Solowey is quite taken with the idea of germinating ancient seeds and wants to know what else she can bring back.
Solowey tells me that, so far, she has managed to sprout a 1000-year-old seed from another species entirely. Neither she nor anyone else knew what it was at first. Date seeds, even ancient ones, are easy to identify. They are large and long, with a characteristic groove running down the centre. But this was a tiny, teardrop-shaped thing, its distinctive features mostly worn away by time. Even as the seedling first emerged from the soil, Solowey remained puzzled.
‘Do you know what a Tinkertoy is?’ she asks me with a laugh. ‘It’s a little post of wood with a sort of slit in it. It looked exactly like a little green Tinkertoy! I realised later that it was a myrrh.’
Myrrh is another tree of biblical fame and has been valued for the scent and medicinal qualities of its resin since ancient times. Even today, myrrh resin is a well-traded commodity and is farmed in Ethiopia, Somalia and other East African countries. Solowey explains that there are a number of myrrh species, some of which were lost long ago. She wonders if this tree, whose life began a millennium ago, might be one of them.
‘We haven’t figured out what kind of myrrh [this is] yet,’ she says. ‘It may be extinct, in which case I have a genuine extinct tree.’
The seven Judean date palms and one ancient myrrh that Solowey has sprouted are not the only examples of extreme longevity in seeds. There have been others. Before Methuselah and Hannah came along, the previous record for the oldest seed ever germinated was held by a lotus flower seed that found itself in a rather unique geological situation.
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If you trace a finger along China’s coastline, beginning in the south at the border with Vietnam and ending at the border with North Korea, you’ll find yourself making a large, languorous ‘S’. Granted, it is a rather bottom-heavy ‘S’ and it leans to the right, but you get the idea. As your fingertip glides along, it will pass by four seas. First, the South China Sea, then the East China Sea, then the Yellow Sea, which rests between mainland China and the Korean Peninsula. Finally, at the very top, is the Bohai Sea. It’s more of a small gulf really, comprising a series of bays. Here, your finger will come to rest on the Liaodong Peninsula, which juts out into the Bohai, creating a final inward curl at the tip of the ‘S’.
Liaodong is a remote and geologically unsteady place. Historical accounts of earthquakes in the area go back as far as local records have been kept. Geological evidence of tectonic troubles goes back further still. One earthquake in particular, most likely the one that occurred in the winter of 1484, caused an entire lake to disappear. Up until then, Xipaozi Lake had sat several kilometres inland from the coast, as it had done for thousands of years. In its sudden restructuring of the landscape, the earthquake caused the lake to drain down the Anzi River and into the Bohai Sea. What remained would fascinate botanists for centuries to come.
The lakebed had been dry for well over 400 years by the time Ichiro Ohga showed up in 1923. Working as a botanist for the South Manchuria Railway Company, part of Japan’s territorial foothold in the region, Ohga was far more interested in plants than the geostrategies of empires. He was particularly fond of lotuses (Nelumbo nucifera). When he heard rumours that centuries-old lotus seeds had been found buried in the peat and sediment remains of a former lakebed, he wanted to see for himself. When he arrived he met a local man named Liu Guay San who explained that his family farm stood where the lake had once been. Liu showed Ohga some of the remarkably well-preserved lotus seeds he’d found and said there were more where those came from. It turned out there were thousands and thousands of ancient lotus seeds buried there – so many, in fact, that it’s likely the lake had long been used for lotus farming, maybe since the Sui Dynasty around 600 CE, and perhaps well before that. Lotuses were one of the earliest plants to be cultivated in China, with records of lotus farming going back around 3000 years. Fossil pollen from Xipaozi Lake suggests lotuses had been growing there for more than 2000 years.
Together, Ohga and Liu struck up an informal research partnership. Liu was happy to share local history with Ohga, such as the time there was a lake and then there wasn’t. Liu also collected thousands of seeds, digging them out of layers of peat and loess sediment and giving them to Ohga, who was able to germinate many of them in his laboratory in Japan. Ohga was deeply grateful to Liu, and the two might have continued their collaboration and friendship for years, absorbed in the marvels of ancient lotuses, but we will never know. By the 1930s the rising tensions between China and Japan escalated into war. Ohga could not return to Liaodong. Tragically, because of his association with Ohga, Liu was accused of being an enemy collaborator and was executed.
And still the lotus seeds quietly lived on. Over the years, Ohga shared his lotus seed collection with other botanists around the world, including palaeobotanist Ralph Chaney in the United States who, in turn, sent one to Willard Libby at the University of Chicago. It was 1951 by then and Libby was in the midst of developing a new technology called radiocarbon dating. According to Libby’s analysis, the lotus seed was 1040 ± 210 years old. Libby would go on to win a Nobel prize for his development, but unfortunately, early versions of radiocarbon dating were highly destructive and required a large sample. In pursuit of chronological accuracy, the entire seed was combusted – 1000 years, give or take, reduced to ash. We will never know if it had been alive.
Research by University of California, Los Angeles botanist Jane Shen-Miller suggests it might have been. In the early 1980s, Shen-Miller and her colleagues acquired four lotus seeds from the Beijing Institute of Botany, which were from the same lakebed. The hard casings were filed to allow water to penetrate, then the seeds were gently soaked. Three of them germinated. One by one, the seed casings split open to reveal a nascent shoot, a slender, hopeful thing seeking the light. Then, one by one, they were incinerated – radiocarbon dating was still a voracious process. But it produced results. The oldest seed was estimated to be 1288 ± 271 years old. It was the oldest directly dated, viable seed on record, and it remained so until Methuselah, and then Hannah. Fortunately for the Judean palms, radiocarbon dating now requires a much smaller sample: a discarded seed casing following germination suffices nicely.
Depending on whom you ask, the longevity records set by that lotus seed and the Judean palm seeds were completely blown away in 2012 when Russian scientists announced they’d successfully regenerated an ancient narrow-leafed campion (Silene stenophylla) from the tissue inside a small fruit that was tens of thousands of years old. Whether or not it has earned the top spot in seed longevity comes down to semantics: it is arguably the oldest viable seed tissue, but it is not the oldest germinated seed.
Silene stenophylla fruits were discovered in north-eastern Siberia, buried nearly 40 metres down in burrows dug by squirrels. Of course, these were arctic ground squirrels of the Late Pleistocene, which looked far more like sturdy, well-insulated gophers, with claws that could put out an eye, rather than the skittish, fluffy-tailed things you’ll find in New York’s Central Park. Their burrows were big and sinuous and, importantly, meandered deep into permafrost sediment that had not thawed since the last ice age. As a consequence, the fruits they’d taken into their burrows were incredibly well preserved. Radiocarbon dating of one fruit in particular revealed it to be around 32,000 years old.
Campions are not large plants. They are short-branching perennials and biennials that flower in late spring and early summer. Fields of white-flowered Silene stenophylla still grow in the Siberian tundra, although 32,000 years ago they were far more likely to be trampled underfoot by a woolly mammoth, or even a woolly rhinoceros.
The ancient fruit was tiny, only several millimetres long, but it contained scores of minute seeds, each smaller than a millimetre, as well as placental tissue in the centre of the fruit. The fruit was immature and not fully developed, which is perhaps why attempts at germinating the seeds were unsuccessful. Undaunted, Svetlana Yashina and her colleagues tried the next best thing. They extracted the immature fruit tissue and cultured it in a nutrient-rich mixture. From this, shoots and roots emerged. The seedlings were potted and the stems grew, producing narrow deep-green leaves. Still, after all this time, the young plants were in no hurry. Written in their ancient genetic code were certain immutable rules that had been set down far earlier than the Pleistocene, one being that they would spend most of their energy growing roots in the first year – reproduction can wait. And so, Yashina and her team waited too, until one day, well into the plants’ second year, tiny white flowers bloomed at last.
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Another story of seed longevity begins in 1967, when archaeologists were excavating the ruins at Santa Rosa de Tastil in north-western Argentina. One day, they discovered an intriguing necklace in one of the tombs. It appeared to be made of nuts from a Juglans australis tree, a member of the walnut family. Walnuts, as a rule, do not rattle, but these ones did. Further investigation revealed that seeds of the canna lily (Canna compacta Roscoe) had been placed inside the walnuts, perhaps as they were still growing, precisely so the walnuts would rattle.
All the evidence suggested the artefact was very old. Radiocarbon dating of human remains found in the same tomb indicated they were approximately 530 years old. This suggested the remains – and by association, the necklace – were from the early 15th century CE. This was consistent with what was known about Tastil, that it was decidedly a pre-Columbian site and arguably pre-Incan. The Incas, though contemporary, had not yet expanded beyond Peru, nor even contemplated great feats of civil engineering atop Machu Picchu, when Tastil was built by local indigenous peoples. By its heyday in the late 14th and early 15th centuries, the town had expanded to several hundred buildings housing a few thousand occupants, and it served as an important trading hub. Excavations have turned up peanut seeds from warmer climes, and even seashells. Those walnuts perhaps came from the subtropical cloud forests just on the other side of the Andes, where they still grow today.
Canna seeds are so compact and sturdy that they are likened to shotgun pellets. Anthropologist Eduardo Mario Cigliano and his colleagues at the National University of La Plata wondered just how sturdy these particular seeds were. They recovered three seeds from the necklace and were able to germinate one of them. But rather than kill the nascent plant in pursuit of a radiocarbon date, they let it grow. This earned Cigliano and his colleagues some criticism, as there were strong doubts that the seeds were as old as the surrounding tomb. In response, they radiocarbon-dated the walnut from which the seed had been extracted and found that the necklace was about 600 years old.
Then there is a somewhat explosive example of seed longevity. It concerns a handful of mimosa tree seeds (Albizia julibrissin) that had been collected along with numerous other botanical specimens during Britain’s first diplomatic mission to the Chinese Imperial Court in 1793. Given the mission’s novelty and importance, everything was meticulously documented, including the mimosa seeds, which were catalogued and stored in the Department of Botany at the British Museum in London’s South Kensington. They might have remained there, safely tucked away, had the German Luftwaffe not shown up. Early in World War II, the British Museum’s most valuable items had been evacuated to the London Underground in anticipation of German air raids. There was neither the time nor the resources to relocate everything, however, and priceless artefacts like the Elgin Marbles and the Rosetta Stone took precedence over seed collections of uncertain value. As such, the mimosa seeds were still in storage in the early hours of 9 September 1940, when German bombers dropped tens of thousands of bombs on London. The Botany Department was hit. The Herbarium, where plant specimens and seeds were stored, was on the top floor and sustained major damage. Firefighters and civilians spent hours dousing the flames with water, saving what they could.
I’m not exactly sure who made the discovery several weeks later, although there’s a good chance it was James W Ramsbottom, then keeper of botany at the British Museum. I can just picture him, in his round wire-rimmed glasses, gingerly stepping through what remained of the charred and water-damaged rooms. He must have been distraught to see what had become of the collections. But sometimes in the most ungenerous circumstances, life just persists. There, among the wreckage, were the mimosa seeds that had been collected in 1793 – and they had sprouted.
In this case, perhaps the environmental conditions had been strangely ideal. It’s now known that mimosa seeds will break dormancy when exposed to heat and soaked in water. The incendiary bombs and the fire-fighting efforts had provided both. All up, the seeds had lain dormant for 147 years. Ramsbottom later reported in the journal Nature that three of the seedlings had been planted at the Chelsea Physic Garden by the Thames. By the following spring they had grown into thriving young saplings. Unfortunately, the bombings continued, and in May 1941, during the final days of the Blitz, some bombs fell on the Chelsea Physic Garden. Only one of the mimosas survived.
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Not all claims of extreme longevity in seeds have stood up to scrutiny. In 1967, a team of Canadian scientists reported in the journal Science that seeds thought to be at least 10,000 years old had been found in Pleistocene lemming burrows deep in the Yukon permafrost. The seeds were germinated in laboratory conditions and grew into healthy arctic tundra lupines (Lupinus arcticus). For more than forty years, they were viewed as the most remarkable example of extreme longevity in seeds, but not everyone was convinced. The evidence for the age of the seeds was more circumstantial than anything else, and the seeds themselves – because they were germinated and not burned to a crisp in an early radiocarbon dating instrument – were never directly dated. The matter was settled in 2009, when radiocarbon dating of other seeds preserved in the same burrow revealed the plants had been grown from modern seeds that had contaminated the original site.
While this was clearly a case of closer scrutiny correcting an earlier error, there have also been some downright dubious claims of seed longevity. Take, for example, the case of Egyptian mummy wheat. One of Victorian England’s many peculiar features was a sudden widespread fascination with ancient Egyptian culture and artefacts. From museum exhibits and newspaper headlines to home furnishings and fashion, Egyptomania pervaded popular culture. During the 1840s, rumours emerged that wheat grains found in ancient tombs alongside mummified pharaohs were still viable. In a 2017 article published in Open Library of Humanities, University College London archaeologist Gabriel Moshenska explains:
The myth that wheat, peas, bulbs and other plants could germinate after millennia spent sealed in ancient Egyptian tombs was a popular and pervasive one in the nineteenth and early twentieth century in countries including Britain, France, the United States, Canada and Australia where the revitalised grain was claimed to provide extraordinarily rich yields.
Of course, there were sceptics, he says: ‘In the early 1840s, the British Association for the Advancement of Science had begun the first controlled experiments into the vitality of mummy wheat. Without fail these tests, and others over the following decades, were unsuccessful.’ Despite a steady stream of empirical evidence that wheat found in ancient Egyptian tombs was not viable, the myth, and indeed the sales, persisted quite strongly well into the next century.
These examples of extreme seed longevity make for a fascinating list, but not a long one. It seems 32,000-year-old flower seeds may be viable but do not germinate by themselves. Ancient lotus seeds do not germinate by the dozens. Judean date trees have only sprung forth from seven out of dozens of ancient date seeds that have been planted. These are exceptions. But how is it some seeds can achieve such life span extremes and not others? Well, for a start, seeds are a lot stranger than many of us may realise.