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cc >> Welcome, everyone to Wednesday Nite at the Lab. I'm Tom Zinnen. I work here at the UW-Madison Biotechnology Center. I also work for UW Extension Cooperative Extension, and on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite at the Lab. We do this every Wednesday night, 50 times a year. Tonight it's my great pleasure to get to introduce to you Dean Peter Crane. He is the dean of the Yale School of Forestry and Environmental Studies. He's also an author and most recently the author of a book

called Ginkgo

The Tree That Time Forgot, which will be the topic of his talk tonight. He was born in England in a place I can't remember. >> Kettering. >> Kettering. Thank you. He went to school at the University of Reading, and for the rest of us, that looks like Reading, but it's pronounced in England as the University of Reading. He got his bachelor's there and his PhD. From 1992 to 1999, he was the director of the Field Museum in Chicago. And from there he moved on to be director of the Royal Botanic Garden in Kew, England, which is-- Yes. It's not every day that people get really excited about a botanic garden, but there is none finer. His appearance here tonight is in part due to a friend of his who lives over in Mineral Point. I appreciate that, Jim. And I'm looking forward to his talk. Please join me in welcoming Dean Peter Crane to Wednesday Nite at the Lab.

APPLAUSE

called Ginkgo

>> Thanks, Tom, very much. It's a great pleasure to be here and to have the opportunity to talk about ginkgo. Kind of a little bit of introduction to start with. I work on fossil plants, and particularly the integration of information from fossil plants with information from living plants. And, as Tom said, my academic career has been sort of focused on doing research in that area, and I've written a couple of books before. Here are two of them. But probably not books that anyone other than a specialist would want to read.

LAUGHTER

called Ginkgo

And they were great for my CV, maybe good for my career, but they probably weren't of very broad interest. And so I thought a few years ago that I might try to write something that was of a little broader interest. And casting around for different topics, I eventually decided that it might be good to try to focus on ginkgo. And I hope by the end of this evening you'll agree that the story of ginkgo is a pretty fascinating one from many, many different perspectives. Now, as Tom said, one of the difficult things about writing a book is deciding on the title. You'd think that would be straightforward, but we went around and around on a whole bunch of sub-titles, and eventually settled on the one

that Tom mentioned

The Tree That Time Forgot. But what I really wanted to call

it was Ginkgo

An Evolutionary and Cultural Biology. That didn't work so well for the marketers, but it really does describe what the book is about. So I think of this book as a kind of biography of a very special tree. And like any good life story, it has its ups and downs. So in the case of ginkgo, you can talk about its origin and its proliferation and its spread across the planet but then, paradoxically, its decline and almost extinction until, through its association with people, it was not only saved but went through an amazing renewal and even a resurgence. So ginkgo today is a plant that just about everybody knows, and in a way it's kind of a good news story because we hear a lot about plants in trouble. Ginkgo is a situation where its association with people has really helped. Now, in thinking about the book, one place that I decided to start was with this particular tree. And this is one of the oldest ginkgo trees in the UK. Probably one of the oldest trees, ginkgo trees, in Europe. Was planted around about 1761. And it grew in Kew Gardens about a hundred yards from where we lived when we were based at Kew. And I like to think of it as one of those great trees that if you could interview it, it would have some amazing things to tell you. It would perhaps tell you about George III and Sir Joseph Banks who were there when it was planted. It would perhaps tell you about the Victorian era of Kew. It might tell you about Virginia Woolf, who liked to sit underneath that wisteria and write. It was a wonderful, wonderful tree, but if you want to see really big trees, big ginkgos, then you really go to the east. You can find huge ginkgos in Japan and in Korea and of course especially in China. And we all kind of know and love ginkgo. Once you've seen that leaf, you're not going to confuse it with anything else. It's just about one of the most distinctive leaves of any tree that we have. And it sort of captivated artists. Here's a lovely painting by Rory McEwen of a single ginkgo leaf. This is a huge canvas. Here's another one where the ginkgo leaf itself, this comes from the Chinese city of Suzhou, the famous gardens in Suzhou, and printed onto that ginkgo leaf is a little poem. And also an image of the so-called Master of the Nets Garden, very famous garden in Suzhou that's partly reproduced in the Metropolitan Museum in New York. And ginkgo is a tree that is very much associated with the east, and just to remind me to say that, I wanted to show you these two beautiful contemporary pieces of botanical art. One from China and one from Japan. But ginkgo is a tree too that many people identify with. Here's a memorial from the Brooklyn Botanical Garden dedicated to Dean Clay Osborne in 1939 by his wife, and it shows a little sprig of ginkgo leaves. So ginkgo is a tree that's distinctive, has this amazing leaf, and I like to think of it as kind of a tree that's got kind of a brand. So I'll talk a little bit more about this. But as I go around the country, I'm very attune to ginkgo now, and so I'll see the Ginkgo Spa, the Ginkgo Hotel, the Ginkgo Coffee Shop, and here is Ginkgo Land in Germany selling all sorts of ginkgo paraphernalia It's that amazingly elegant, simple, beautiful leaf. And I love to show this image, which I took on the boardwalk to a very famous ginkgo tree at a temple in South Korea. Do you see how easily it becomes sort of stylized and turned into this little T and, in this case, painted in yellow, and of course that's because at this time of the year ginkgo leaves are that color. Absolutely amazing. I can see that they're just turning that way in Madison right now. Absolutely beautiful. And when ginkgo is at that time of the year, it's worth its place in any garden. In the kind of gray days of autumn, it really sparkles. The leaves gradually turn yellow from the tips very often. But those of you who are sort of a ginkgo-philes like I am will know another thing about ginkgo, and that is that it has the most synchronous leaf drop of any tree that I know. So you'll go out there on one November morning, and overnight it will have dropped perhaps 80% of its leaves. And around the base of the tree will be this amazing halo of these extraordinary yellow leaves. So here are the seeds of ginkgo, and here are some that someone brought in this evening. You can come and smell it later.

LAUGHTER

it was Ginkgo

It doesn't smell so great. And the Chinese common name-- Yeah, they're not good. The Chinese common name for these things is a silver apricot. And they do look a bit like a kind of apricot, but they certainly don't smell like an apricot, and they have this kind of silvery, waxy sheen to them. And we'll talk more about that in a moment. So I was just looking through the slides I might use. I like this one from the Central Park Conservatory. Someone was just telling me before we started about a female ginkgo tree that we cut down. It's a little harsh, really, to cut it down just because it smells a little bit in the fall. It's beautiful the rest of the year, but I do know people who've taken matters into their own hands and tried to get rid of that female ginkgo tree that might be outside their home. But one of the interesting things about ginkgo is the process that leads to these rather disgusting, smelly seeds that are produced at this time of year. The process starts probably, here in Madison, probably around April time just as the leaves are coming out. So just as the tree is starting to leaf out. And I should have mentioned already that of course there are two sexes, two different, there are male and female ginkgo trees. That happens in some other trees it's not so common. But on the male trees at the time that the leaves come out, you will see these little pollen catkins produced. They're produced on those little short shoots. Whether I can indicate that on the slide. So here's the short shoot, and then there's the catkin. And each of those catkins is in the axil of one of these young developing leaves. And on a nice dry spring day, those catkins will elongate dramatically. The little pollen sacks that have literally tens of thousands of pollen grains in each pollen sack will split open and the pollen grains, which are about 40 thousandths of a millimeter long, will blow away in huge clouds. So that's the beginning of the process the leads to these things. What's happening on the female trees is that the structures that will develop into these seeds are already there. They've been produced on the short shoots too on a different tree. And at the tip of these young ovules, soon to be seeds, you have this little projection, little opening into the interior of the ovule, and that produces a wonderful little droplet. And so one of those pollen grains that's floating around randomly in the air has got to find its way to that little droplet to start the process of reproduction in ginkgo. Pollen grains will then be drawn back into the ovule, taking with them the male gametes, the fertile cells. And then over the course of the summer those little ovules will develop into structures like this. So they're not apricot colored yet, but they're quite mature. So this is what they look like in around about August. But what's interesting about ginkgo is that by this time fertilization has still not happened. That is to say, the male gamete and female gamete have still not fused by this time even though ginkgo has gone ahead and produced the food reserve for the embryo, that's what that increase in size is all about, fertilization hasn't taken place yet. And that actually takes place around about the end of August, beginning of September several months later. And it's a kind of unique feature of ginkgo. And I show the picture of this man. This is --, the Japanese scientist who was the first to observe those last intimate details of ginkgo reproduction. So he was working at the University of Tokyo in the 1890s cutting up ginkgo seeds to try and understand them. He was really a sort of laboratory technician and illustrator, but a very, very good observer. And what he found was absolutely astonishing. So here's his drawing on the left, and here's a photograph on the right. And this is the actual male sex cell, the male gamete, that fuses with the egg cell inside the ovule. But what's so spectacular about this and what was so completely unimagined was that this little male gamete is a swimming cell. It's a swimming sperm cell, and that's very, very unusual for a tree. No other tree known at that time showed that kind of biology. All of the conifers we have, all of the flowering plants we have, none of them do that. They do fertilization in a different way. But what's interesting about this mechanism is it recalls the process of fertilization, for example, in ferns or in mosses. So this is an evolutionary holdover. It's kind of like the platypus producing eggs. It's like amphibians going back to the water to reproduce. So this is something that was really quite astonishing. A very important discovery, very well known in Japan, because, remember, Japan only opened its doors to the west in the middle of the 19th century and this was one of the very first major scientific discoveries that made an impact on the international scene. So this was one of modern Japan's first contributions to science. So this very interesting young woman who was in Tokyo in 1904, this is Marie Stopes. Marie Stopes, for those of you that don't know, was a great exponent of women's rights, particularly women's reproductive rights later in her life. But earlier in her life, she was a paleobotanist, and she was also very interested in ginkgo. She spent a whole year at the University of Tokyo by herself in the early part of the 20th century. Pretty extraordinary woman. And she describes in her diary going back to the same tree that -- studied, and cutting up the ginkgos to see those motile sperm cells working. So that's the story of how you get these. So what's happening in these right now is that fertilization has now happened. The embryo inside is starting to develop, and these things will be shared in a few weeks time often. And then in the right circumstances they probably will germinate. I don't know whether they do germinate around here. I'd love to hear from you afterward about whether they do. They certainly do in Chicago. They certainly do in places in Korea where I've watched them. They certainly do across the street from my office in New Haven. And you get these wonderful little seedlings coming up. And take a look at those leaves. They're kind of interesting. Compare them with the one that I showed you at the beginning on the front cover of the book. They're much more deeply divided than the sort of characteristic leaves of ginkgo. And ginkgo, as it grows, I pointed out the short shoots, has leaves of different shape on the short shoots versus the long extension shoots. The extension shoots have these deeply divided leaves or bilobed leaves, and the short shoots bear leaves with a more fan-shaped profile. This is one of my favorite illustrations of ginkgo because it also comes from Japan and it's painted on a board made out of ginkgo wood. So we had a whole collection of these at Kew, and every illustration was on the wood of the species being illustrated. And this is the one of ginkgo, and it's framed with those little shoots. And it shows very nicely the developing ovules here and then the pollen cone up here, the leaves and the short shoots just here, and then the mature seeds. This one actually shows two seeds on a single seed stalk. Most of these just show one, and we'll talk about that in a moment. I love this illustration because through a little bit of detective work we figured out where these were made, when they were made, and for what purpose they were made. They were made, again, at the University of Tokyo. We don't know how it came from the University of Tokyo to Kew Gardens, but they were painted in 1878 by an early botanical illustrator at the University of Tokyo, Chikusai Kato. And last year I went back to the University of Tokyo, and in their archives we found some of the sketches on which those drawings were based. Here's one of his preliminary sketches. Here's a more finished one, and then here's a black and white. We think that these were prepared, the boards were prepared for teaching, and a Harvard professor who is at the University of Tokyo at exactly this time notes them in his diary and actually illustrates one of them. But we also think that Chikusai Kato was preparing a whole series of illustrations to illustrate the plants from the University of Tokyo's Koishikawa Botanic Garden. So one of the things the ginkgo does well is it suckers well from the base. So it sends up sucker shoots from the base. And this is a photograph of some of those sucker shoots from a tree in China. And again, you can see the very deeply divided leaves. And I show them to you, again, to compare in a moment with the fossil leaves. But I just want to say that ginkgo is a tough old tree, and this is perhaps the best example that I've found. This is the second life of a ginkgo. So this was an 80-foot tall ginkgo tree that was cut down, and they left a three-ton stump to be turned into a memorial plant. And as they left it there, it had been cut off at the roots and it had been cut off above. So it was just a stump. It started to sprout again just fine. So it now has a home on the Reed College campus. It has its own nickname, and the last time I looked, it was doing just fine. So ginkgo is a tough resilient tree. One of the things that you may not have seen, though, is this curious mode of growth. So in all ginkgos, in some of the old ginkgos that I've seen in China or Japan, you get these downward growing branches. And you rarely see them in trees in North America, but here are some. And what happens is when these hit the ground, they then start to root, and then they send more suckers back up. So when you see one of these big old ginkgos, for example one that I saw in northern Japan, you can hardly tell where the central truck is anymore because it's just become an enormous great big thicket. So in addition to this mode of sexual reproduction, ginkgo will also reproduce itself vegetatively very effectively. And, of course, when you get obsessed with anything in biology, you start to see little details that may be kind of important but that don't get reported in the textbooks. So this is actually from the male tree at Kew. But you see all of a sudden it's started to produce a few seeds. So the sex of these trees is not fixed. So I was taught when I was an undergraduate that ginkgo had an XY chromosome system just like we do, but obviously there's more flexibility there. And so in some male trees you get the production of a few ovules. As I like to say, that might be a useful trick if you're a lonely male without a mate.

LAUGHTER

it was Ginkgo

To be able to do that every now and then might be a really useful trick. And then a friend of mine at Kew who germinated a bunch of ginkgo seedlings, took this picture. When the pollen grain gets into the micro pod, it's actually carrying two male gametes. And, of course, more than one pollen grain may get in too. And there's more than one egg there waiting to be fertilized. So occasionally, as you see in this picture, a ginkgo will have twins. So this is a single ginkgo seed with two embryos emerging from it. So back to the sucker shoots. So here they are, deeply divided. And here are the leaves of fossil ginkgo from the early Jurassic of Ishpusta in Afghanistan about 190 million years before present. And I don't think anyone would mistake these for anything other than ginkgo. One of the reasons that ginkgo has such a good fossil record is that the leaves are relatively tough. We think that ancient ginkgo, much like its modern counterparts, was a plant like to live near water, and therefore it was growing close to water. Its leaves were dropping into sediments, and so there's a high probability of them being preserved. But also, crucially, ginkgo is a very distinctive leaf. And so when you find something like this, you associate it immediately with ginkgo. And in fact, at that time, 190, 180, 140, 150 million years ago, ginkgo was widespread. Here are some ginkgo leaves from a very famous locality in Yorkshire that I've often visited, and it's the most common thing in those river sands to find these deeply divided ginkgo leaves. And you see the material here is black. You can actually pick that material off the fossil. There's still organic material left, and with the right techniques you can prepare those leaves and you can produce, this is actually from a modern ginkgo, but you can produce something that looks very similar to this from a fossil ginkgo. The cuticle, the waxy covering of the leaf, can be extracted, and if you look very carefully on this, you'll see these little hulls here and here, here, so on, those are the stomata that let the CO2 into the leaf and let oxygen out of the leaf. And you can find those same distinctive features in the fossil material. People have used fossil ginkgos and looking at how many stomata they have to try to get a rough estimate of what the CO2 concentration in the atmosphere was like in the past. Higher CO2 concentrations, you need fewer stomata to get the same amount of CO2 into the leaf. So ginkgo is around a long time ago, 190 million years ago. So where does it sort of sit in plant evolution? I like to show this to my students. I wish someone had shown it to me because it just sort of summarizes the whole of the plant kingdom. If you can memorize that, you've kind of got a good map to find your way around the plant kingdom. So these are all land plants, and I just come over to this one here. So, seed plants. So there's only five groups of living seed plants. Angiosperms down here. 350,000 living species of flowering plants. Gnetales, an obscure group, a little over a hundred species. Conifers, 600 to 700 species. Cycads, 100 to 200 species. Ginkgo, one species. So if we'd have lost ginkgo, we'd have lost a very, very important part of plant diversity. We're lucky that it made its way through. It's still here for us to study and enjoy and try to understand. So where did it come from? I don't have a very good answer for that. This is where idea. This was by Rudolf Florin, a very famous Swedish paleobotanist. He focused on a plant called --, and he thought that might be related to ginkgo based on its very deeply divided leaves. And these are peculiar seed bearing structures. The Russian paleobotanist thought that this is ginkgo here, this one going up to the recent. Thought it was the last remaining survivor of this once much more diverse group in the fossil record. My own view is that ginkgo may have had its origin in plants that look a little bit like this. And that's something that we're kind of actively working on right now. But you see the similarity in the leaves, the way the seed bearing structures are born here. This is actually material from the Triassic of South Africa. I love to show this picture. This is a good friend of mine. He's now well into his 80s. And when I was a student at the University of Reading in 1981, he had just come out of China, one of the first paleobotanist, one of the first scientists to come out of China. We worked together in the lab, but then when he went back, he focused a lot of his efforts on working on the fossil history of ginkgo. And I'm just going to show you some of his beautiful specimens. I have one of his students working with me at the moment who gave me these beautiful slides. So this is some of the material that he worked on. These are beautifully preserved ginkgo leaves from a Jurassic mine in China. And again, you can see that there's lots of organic material there, and they could be lifted off and prepared beautifully. But what was important about Zhou Zhiyan's work was that not only did he have the leaves but he also had the seeds. And he was able by very careful collecting to show pretty convincingly that these leaves, because when you're dealing with a fossil deposit everything is rarely attached to each other so you have to figure out which seed goes with which leaf, he was able to convince just about everybody that these were the seeds that belonged to that ancient ginkgo leaf. And they're kind of interesting. So you see three of them here, but you see they're on these long stalks. They're born singly on these long stalks. And here's modern ginkgo. They don't have those long stalks. The individual seeds aren't on long stalks. There's a single stalk and then you got two seeds left on the end, and they're set what we call sessile. They're right on the stalk. So here is his reconstruction, not of the one that I've just shown you, but of two other kinds of ancient ginkgo plants that he described. And he actually found three different kinds of ginkgo-like plant in the same coal mine in China that he was working on. This is the one that I showed you. This is what he calls ginkgo yimaensis. This is another one that he calls Yimaia. And this is another one that he calls karkenia. So the importance of Zhou's work is that he not only had the leaves but he had the seeds. He was able to see how the seeds were born, and they were born very differently. Here you have relatively few seeds, and they have individual stalks. Here you have a kind of cluster of seeds, and they're born together. Here you have an almost cone-like aggregation of seeds, and the seeds are actually reflexed so that the pollen catching part is facing inwards which doesn't seem like a good idea if you're trying to catch the pollen grains, but actually that's the way that most conifers work. They have their ovules pointing in that way too. So his work, I think, has been really very, very important. And then he described this one, which are really strange. These leaves are very, very small. From the early Cretaceous. His point here in putting this diagram that was published about a decade or so ago in Nature is that there's a sort of pervasive trend towards reduction in the number of seeds born in the seed stalks. And also, instead of being born in individual stalks, they're born almost sessile. So this is an area that's kind of interesting to me at the moment from an evolutionary point of view. And just back in September I was in Japan working with a colleague, and we turned up an old Japanese paper, which shows that these are all the seed bearing structures of abhorrent seed bearing structures of ginkgo. Living ones now. So even though living ones, again when you look closely, there's more variation there, and there's are really quite elaborate structures. And he studied them in good detail, and we're hoping that next spring we're going to go back and collect some of these and look at them in a bit more detail. These are the kinds of things that we need to compare with our fossil material to try and understand how ginkgo fits into plant evolution. And while I'm sort of doing this kind of little riff on plant evolution, I just want to share with you some other things we were talking about in Japan last month, and that is, again, early Japanese authors had sort of recognized this but it hasn't been worked on before in any detail, and that is occasionally on some ginkgos, there's an area outside of Tokyo where there's a whole cluster of ginkgos, and here are the young seeds, but they are born not on stalks but here they're actually on things that look like leaves. So the seeds instead of being born on those naked stalks are actually being born on little leaf-like structures. So these are kind of like the homeotic mutants that you sometimes see in insects. And here's the male version. And so in some cases, here's the male pollen catkin, but here's a few pollen, if I can just get it to work, here's a few pollen producing organs born on a leafy structure. So these reproductive-- Here's a closeup of that. So these reproductive aberrations are really quite interesting. Here's a leaf with a young ovule developing. These are quite strange. And here's one with a mature ovule. So all of these details, which are kind of huge fun to look at, are going to help us figure out this problem, which is where ginkgo belongs in the grand scheme of plant evolution. And this is just a little summary that I put in the book. I have no idea whether it's right, but something like this is what's needed. There are only five groups of living seed plants, as I mentioned. You'd think that figuring out how they're related to each other would be pretty straightforward, particularly with molecular techniques. You can sequence the whole genome of these things if you want. But actually, the molecular results give us very equivocal results. Different genes give us different patents. Different methods of analysis give us different patents. And I think the reason is that these are divergences that happened a long time ago, and much of the relevant diversity has just plain gone. And it's like any other problem in science. If your sampling is bad, your result is probably going to be bad. And the sampling that we have of living plants with just those five living groups is not a good enough sample to answer these deep questions about plant evolution. So that's one of the things that I'm still very interested in. To the extent that I can still get any research done, I'm very interested in answering that question and have been for most of my career. Anyway, back to ginkgo. So you've already got the sense that ginkgo was widespread in the northern hemisphere. It was also widespread in the southern hemisphere. So here's one from the early Cretaceous of Australia, about 130 million years before present. And exactly the same kinds of leaves occur in India, they occur in southern South America. So ginkgo was a plant that was widespread in the southern hemisphere before those southern continents started to split up and go their own way. And I mentioned, too, the work of Zhou Zhiyan. And this is a little graph that he produced. There are all kinds of problems with this graph, but the message is pretty good, I think. So this is time, and this is the diversity of ginkgos measured in different ways. What it shows very clearly is through this middle part of the record here, through the Jurassic and earlier through the Triassic, you had a great diversity of ginkgo-like plants. Between the early Cretaceous and the late Cretaceous, let's say for the sake of argument about a hundred million years ago, before about a hundred million years ago there were quite a lot of ginkgos, quite a lot of diversity of ginkgos. Different kinds of ginkgo species. After about a hundred million years ago, I think we're down to one or two species of ginkgo. So the diversity declines. And that's probably because flowering plants were radiating at that time. So there's a massive vegetational change going on at that time, and ginkgo was one of the groups that declined. Now, whether it was environment or whether it was competition with flowering plants, it's hard to say, but that's where the diversity seems to go out not later. Not at the end of the Cretaceous at the Cretaceous-Tertiary boundary, but much earlier. So then you go through a very interesting phase in the late Cretaceous, let's say between a hundred million years ago and 65 million years ago, where you've got this kind of situation going on. So you've got this kind of rather overweight T Rex here in the foreground with a triceratops in the background. These are the kinds of animals that you would find if you went out to the Hell Creek formation, for example, in North Dakota or in South Dakota. And then you've got a vegetation that includes not only ginkgo, drawn behind the T Rex here, this is the famous Zallinger mural at Yale, but also flowering plants. So if we'd had been wandering around on that landscape, we would have found the plants pretty familiar. Ginkgo, magnolias, all kinds of other things that we'd recognize. The animals, that would be a different story. So anyway, I like to kind of, when you go and stand and look at those ginkgo trees on this campus, remember these guys knew ginkgo too. So then they all disappear 65 million years ago. Cretaceous-Tertiary boundary those dinosaurs are gone, and a lot of other major changes in the animal world too, particularly in the marine realm. Lots of extinction. Ammonites gone, many other things. Ginkgo didn't seem to care about that one bit. So this is from a fossil I collected in North Dakota in beds that are about 55 million years old. It's unmistakable what it is. It's ginkgo. And, yep, the seeds are there too. And in this case, I don't have a good photograph of it, but I just show this to you. In this case, we had these, we were able to, this is ginkgo with its mature seed and a little aborted ovule. So this is one that didn't work. And then when the seeds fall off, you're left with a big scar and then the aborted ovule. We found structures exactly like this in those North Dakota deposits. So we're pretty confident that that ancient ginkgo bore its seeds in exactly the same way as modern ginkgo. One of my colleagues, actually Zhou Zhiyan, very kindly named that plant after me. He called it Ginkgo cranei, which is very nice, but I think if I was to tell the truth, I think it's just Ginkgo biloba. So it probably just needs to be sunk. Those kinds of plants were widespread around the northern hemisphere between 65 million years ago up to around about, at least in North America, 15 million years ago. So we still had ginkgo growing in North America 15 million years ago. Here's a big chunk of ginkgo wood from Washington state. There's a little ginkgo fossil forest there. So the sort of history of ginkgo is it's sort of appearing somewhere in here between about 250 and 200 million years ago. At one point you've got a lot of ginkgos on the landscape, a lot of different kinds of sort of ginkgo-like plants. They decline about a hundred million years ago as flowering plants start to radiate. Then you've got probably just one or two different kinds of ginkgo, excuse me, surviving, and they go all the way nearly to the present, within 15 million years in North America, within a couple of million years in Europe, but they're totally gone in North America and Europe now. And they almost are gone in Asia too. So the only wild populations, according to the Chinese scientists who are studying them, of ginkgo right now are in two isolated populations. One not far from Shanghai, West Tianmu Mountain; one inland at Jinfo Mountain. There are lots of old cultivated ginkgos, of course, across China. And the early explorers, the early plant explorers, from the west, for example Ernest Henry Wilson, who was exploring for the Arnold Arboretum around about 1900, was photographing these remarkable trees. Here's a big ginkgo that he photographed. And he found that they were often associated with temples. And so this is where this idea came from that ginkgo is often a plant associated with temples. It's actually much more widespread than that. It certainly is cultivated, associated with many Buddhist temples, but you also get them in what are seemingly wild situations. This is the population from West Tianmu Mountain, and here's a photograph, this is a photograph that Ernest Henry Wilson took in 1908 in Szechua. Here's that same tree today. You don't get a sense of how big it is. Here's my friend Tony Kirkem at the base of that tree. This is a big ginkgo tree. So, how old are these ginkgo trees? If you look in the Chinese literature, you'll sometimes see them thought to be 2,000, maybe even 3,000 years old. I think that's too old. But I think it's quite plausible that some of these trees may be pushing a thousand years old. Very difficult, often, to find the age of these trees. Here's one that I photographed not far from Nanjing a few years ago. And often, even in China today, still strongly associated with Buddhism. So here are the little prayer ribbons tied to the branches, a little Buddhist alter at the base. And, also, great significance attached, particularly related to fertility, attached to these chi chi. At this time last year I was in Beijing, and just outside Beijing I photographed this one in all of its glory in its fall foliage. Well, moving on quickly. People have been using plants in China for medicines and a whole variety of purposes for thousands of years. But the first time we see ginkgo represented in Chinese literature is not that long ago. It's a thousand years ago. Not 2,000, not 3,000 years ago. And then it comes with these names. Duck foot, that's a wonderful name. Think about the leaf and a duck's foot. Silver apricot, I've mentioned. White fruit, white eye, grandfather-grandchild tree. The tree that the grandfather plants, the grandchild gets to harvest. But what's interesting is that there's good literature records from about a thousand years ago in China, but only for the last 600 years or so in Japan. So ginkgo appears to be one of many plants that were moved from China up into Korea and up into Japan during medieval times. There are many plants in Japan that are of Chinese origin. Here's a couple of large ginkgos in Seoul, South Korea, and they take that ginkgo for the motif of, in this particular case, Confucian university. And so where ginkgo by medieval times, late medieval times, was getting incorporated into Japanese arts, there are lots of these beautiful ginkgo stylized crests. I like this one. Particularly this combines a ginkgo leaf and a crane, which I'm kind of partial to. If I was going to have one, I think I would have this one.

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it was Ginkgo

So, when did the west first learn about ginkgo? Well, the first western encounter with ginkgo came in the, that we know about or that was recorded anyway, came in the early 1690s. And this was through the Dutch trading post. The Dutch had a monopoly on trading with Japan after the Portuguese had been kicked out. The Japanese didn't like their Catholicism. After the Portuguese had been kicked out, the Dutch had a monopoly with trading with Japan for several hundred years. But it was strictly regulated, and it was all controlled through this little island called Dejima in Nagasaki Harbor in southern Japan. And Engelbert Kaempfer was a physician botanist assigned, obviously medicine and botany were closely intertwined at that time, assigned to look after the Dutch on Dejima. And he arrived there in 1692. And you've got to go on the web and read what he wrote about his experiences there, which were pretty fantastic. But when he came home, before he died in 1712, he was able to publish this illustration, which is the first western illustration of ginkgo. He may have drawn it himself. He illustrated the seeds. It doesn't have the male parts. He doesn't understand that the leaves are on short shoots. And he was probably had very little material to go on. He was a very good observer. But he was stuck on that damned island, and they were strictly controlled. They wouldn't let him off. The only times he got to go off was when the Dutch went to what's now Tokyo to pay their respects to the shogun and offer their gifts to the shogun. But he had a good translator, and we think, for various reasons, that his translator was a local young man who became a rather famous translator later in his life. And this is where we first see the word ginkgo mentioned. So this is kind of, ginkgo is the only medieval Japanese word that most of you know, and with a slight Nagasaki accent.

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it was Ginkgo

And he also recorded it as ginan which is another name still used in Japan and --. And then he says arbor nucifera, a nut tree. Folio Adiantino, leaves like adiantum, the maiden hair fern. And that's where the common name of ginkgo, the maiden hair tree, comes from. Kaempfer probably didn't bring living specimens back with him. He brought some scrappy dried specimens. So we're not sure when ginkgo, as a living plant, first made it back to Europe. But we know that it was being grown there as early as maybe the 1830s but certainly the 1850s and 1860s. And we know that James Gordon, a nurseryman in London, was growing it at that time. And Linnaeus, when he described all the plants that he knew in 1753, did not include ginkgo. He probably knew of it from Kaempfer's work, but he'd never seen a specimen And this letter from James Gordon, this nurseryman operating in the East End of London, written in October 1769 to Linnaeus, sends him a specimen of ginkgo. And then Linnaeus had it. He made a herbarium specimen out of it. It's got bi-lobe leaves. It was probably a young plant, that's why he called it Ginkgo biloba. And he gave it that official name, Ginkgo biloba, in 1771, one of his last botanical works. So this tree that we mentioned earlier on at Kew really is one of the oldest in Europe, and certainly one of the oldest in UK. Now, where did those living specimens of ginkgo come from? Well, we don't know. They could have come, there are some old trees in the Netherlands and Belgium. So they could have been brought back by the Dutch from Japan. But equally, there were other European powers operating in Asia at that time. So the British were in Canton, and many of the ships captains were being asked to bring back living material. And I've become particularly interested in this man. This was a young man who never got out of his early 20s but was a very promising young scholar called John Bradby Blake. He was working for the British East India Company, and he was based in Canton. And he was sending living material back, and he was using Chinese artists to make illustrations of the plants that he was sending back. At the Oak Spring Garden Library in Virginia and also the Natural History Museum in London there are illustrations created by anonymous Chinese artists for John Bradby Blake in Canton in the 1770s that were never published, and this is the one from the Natural History Museum that shows ginkgo. So certainly by the 1770s it was being grown, and by 1785, ginkgo was growing in North America because wealthy North American landowners were bringing over horticultural materials from Europe, and they, by the way, were sending American plants back to Europe to be grown there. And this is a 1930s photograph of one of these old trees planted just outside of Philadelphia. Later, another physician on Dejima in the 1820s. This is Fran Sebold, when he got back, did this beautiful illustration of ginkgo. And by the early 19th century, ginkgo was becoming more widely known. And this very famous poem by Goethe was written in 1815. And you see he puts on these two ginkgo leaves. I'm happy to talk more about the poem later. But I mention it here because if you want to see a place that's really pretty obsessed with ginkgos, you need to go to Goethe's hometown in Weimar, Germany, where you can see lots of ginkgos planted on the street, and the only place where there's a ginkgo museum, that I know, with just about every variety of ginkgo for sale there. And just about every jewelry shop in Weimar has ginkgo type jewelry, which my wife is modeling for us this evening.

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it was Ginkgo

But what probably saved ginkgo and why those Chinese were so interested in it a thousand years ago was probably its seeds. They're edible, and even though they're kind of smelly, if you wash that stuff off, you're left with something that looks a bit like a pistachio And inside the pistachio is the food reserve here, and here's the little embryo. So when you eat a ginkgo nut, it's not strictly a nut, it's a seed, but the meat you're eating is the food reserve for the little embryo that will develop there. So I'm sure you can buy them in Madison. You can certainly buy them on the web. You'll find them in Chinatown. So it was probably the nut tree aspect that was important earlier on. And you'll find ginkgo in the pharmacy too these days. These are extracts of ginkgo leaves that are perhaps good for your memory. But the cultural side of ginkgo is so fantastic This is in Korea, a little Buddhist alter, again at the base of an old ginkgo tree. And if you want to learn more about the cultural history of ginkgo and see some really amazing images, you should type in Ginkgo Pages on your browser, which will take you to this amazing site done by Cor Kwant, which has the most extraordinary collection of ginkgo related ideas and facts and images and so on. This is one of her beautiful images. This is I think from Prague where you've had this kind of applique on the outside of a building with ginkgo, complete, I just noticed, with the seeds as well. And ginkgo has been incorporated into Asian art and even some slightly wacky British art.

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it was Ginkgo

And you can have a ginkgo chair too, if you like.

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it was Ginkgo

And, of course, ginkgo, we know today, is a very popular street tree. And I've already seen it growing on the streets here in Madison. It's a tough tree. And here are some in Japan. And you'll see they can be heavily palisaded and they still will come back. They'll still produce those extension shoots. Ginkgo started to be cultivated widely in North America around about the turn of the century. This is from the 1912 Biltmore catalog where it mentions ginkgo, and it says, "has proved most successful in Washington city as a street and avenue tree." So if you look at sort of inventories of street trees, in Philadelphia there's 1,300 ginkgos, San Francisco 1,200 ginkgos. Most of them are pretty small, but in New York there's a huge

number

60,000 ginkgo trees in New York. And if you go to Manhattan, it's one of the commonest trees that you'll see. And those street trees have real value, and you can actually calculate that value in various ways. I won't go into it, but they're a valuable part of our urban landscape. And horticulturalists have had fun because the natural mutants will arise. Here's one where the leaves are kind of tubular. Here's another one where the leaves are variegated. Ginkgo is a favorite bonsai. And if you're really up for a bit of serious pruning, you can grow ginkgo up the wall, as it is here. This is the University of Cambridge in the UK where they're espaliering ginkgo up the wall of the plant science department. So here's my favorite ginkgo tree again. 1761. And what I like about this, and I think this is sort of central to why we like trees, is that they do cross generations. And they outlive us. And they outlive our kids and our grandkids. Here's my favorite ginkgo from 1889. A lot has happened in the world that that tree has seen since 1889. So I think the ginkgo life story is a really interesting one. It's got an evolutionary and cultural component, but what it really speaks to us about is time. And I finished the book with this. It helps to kind of calibrate the speed of change in our lives and asks us to think more carefully and more deeply about everything we lose when we're always so focused on the short-term rather than the long-term. So I hope you've enjoyed this tour through the life history of ginkgo. It's been a real pleasure to be here with you tonight here in Madison. Thank you very much.

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