So welcome, everyone, to this webinar Roots to Seeds: the Evolution of Plant Science.
Thank you very much for being here. My name is Helen Cook and I'm the Education Officer at the Bodleian Libraries.
Just to let you know a few practical things before we start. We are recording the event but as
this is a Zoom webinar, your video and audio are turned off and you won't appear in the video.
We will share a link to the recording about a week after the event.
This event is part of the celebration of the 400th anniversary of Oxford Botanic Garden
and Arboretum, marked at the Bodleian Western Library by a wonderful exhibition, Roots to Seeds, which is on until the 24th of October.
This evening we will be looking at a collection and expedition and the plants that have
contributed to four centuries of botanical teaching and research at the University of Oxford.
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So once again, welcome. The plan today is to discuss the past, present and future of botanical research and teaching through three fascinating items
and I'm delighted to welcome our speakers, Professor Stephen Harris. Druce Curator
(Herbaria), Associate Professor of Plant Science and curator of Roots to Seeds.
and Chris Thorogood, Deputy Director and Head of Science Oxford Botanic Garden and Harcourt Arboretum.
So our first object you can see on the screen is the Bobart the Elder Herbarium. Stephen,
please tell us more about Jacob Bobart the Elder and his herbarium. Who was he and
why does the herbarium feature in the seminar this evening? Thank you, Helen. So Bobart the
Elder was the first gardener at the Botanic Gardens.
He was appointed in 1642,
twenty-one years after the garden was founded. They didn’t really start growing any plants for twenty-one years.
Bobart, he was a German, he was a German soldier publican.
In fact, he had the pub across the road from the Botanic Gardens.
He was close to home and he built up this collection of plants, medicinal plants, a whole range for different purposes.
And in addition to the living collection, what he did was he also collected dried samples.
And this was really unusual at the time. And he built up this object that's in front of you.
This is Bobart the Elder’s personal herbarium, the founding herbarium of the university
And it dates from about the late 1650s, about three and a half thousand specimens in it.
And the page that you can see open, you can see a whole range of different Auriculas at the top.
And in fact, Bobart the Elder was a very well-known Auricula breeder of the time.
And so what we have is this collection that he was building up,
It was evidence of the things that were growing in the gardens and of course, herbaria have continued to build up.
So I am the curator of the University's Herbarium.
The University’s Herbarium is about a million specimens today.
Over the last 400 years or so, we've built up this collection and this collection continues to grow.
And we go onto the onto the next slide.
What we will see, in fact, is a modern specimen. So you'll see that it's not a separate book.
They're housed as individual sheets.
And this is one of about a million specimens in
our collection, it's about one of three hundred million specimens worldwide.
So these specimens, each specimen tells us when and where something was collected.
It becomes fundamental to our understanding of all of the biological diversity that is on the planet.
And they can be used in a very wide range of different ways.
And so this specimen is a recently collected specimen from Gabon.
And in fact, it's a new species. So this is, in fact, the specimen that was used when this new species was described.
And we have lots of these so-called type specimens.
So it's a dynamic living collection, but it has its origins in that book Herbarium that we saw earlier in terms of Bobart’s work.
And again, Bobart’s work was a very novel thing to be happening at that time in Britain.
Thank you. So, you mentioned it's a kind of living collection,
so I wonder, Chris, if you could tell us a little bit more about the living collections in the Botanic Garden today?
Yes, of course. So to start off, I'll acknowledge, of course, that it's our 400th year.
So we're the oldest botanic garden and Oxford Botanic Garden was established first as a physic garden,
as we're hearing about from Stephen's piece, in 1621. And some of the plants were grown for teaching purposes. Preceding that,
the first botanic garden was founded in Padua, in Italy, in the fifteen hundreds.
And like Padua,
Oxford Botanic Garden has been a centre of botanical research where people have been able to marvel at plants and the wonder of plants for centuries.
And of course, that's really what the Roots to Seeds exhibition is all about.
And today, four and a half centuries later, there are about two and a half thousand botanic gardens worldwide.
And together with the herbaria, as Stephen was talking about, they hold many millions of living and dried plant specimens.
They're fundamental. I read a report recently that estimated one hundred and seven thousand living species were held by the world's botanic gardens.
So you can imagine the incredible conservation value they hold.
So today, in the Botanic Garden and the Arboretum, we hold a collection of about five thousand different types of plants,
both species and varieties and cultivars, and they’re temperate, they’re tropical,
some are exceptionally rare or endangered in the wild.
And like other botanic gardens, our collections,
they are sourced from different places around the world and from different, what we say, phylogenetic divisions or families.
So we've got a really assorted, a real diversity of different plants, which is what Botanic Gardens hold.
So if, for example, we think of our conservation collections for a moment.
We carry out conservation locally here in Oxfordshire.
So we've got some rare plants growing just about 10 metres where I'm sitting now that are very rare in Oxfordshire.
And we've also got plants that we've collected with other botanists from around the world.
So we do conservation work, for example, in the Canary Islands and in Japan in particular,
For quite a few years now, a conservation-related project has been ongoing.
Japan is, by the way, a biodiversity hotspot.
So one of 30 odd places around the world where there's a particularly rich diversity of species in quite a vulnerable or sensitive area.
And so we've worked extensively with Japanese colleagues in Japan and we've collected four hundred species.
And I wanted to show you, no, not that one, I wanted to show you a tiny one. It is actually really,
really beautiful, but I'm not sure I can do it justice, or not on a Zoom call.
This is an Aristolochia, Aristolochia Zollingeriana
and we collected seeds of it in 2018 in Okinawa, one of the tropical islands in the south of Japan.
And this is a plant that is quite basal in the language we use,
which means in a sense, it's one of the more primitive of the flowering plants.
And that means that this is a plant that not only has conservation value, it has teaching value as well.
A couple of minutes before we went live, I announced that I was going to share a surprise.
So I'm going to show you something that I think Stephen will find really exciting and he doesn't know what it is.
So you're about to witness his live reaction.
So this is something that we've been growing in the Botanic Gardens, and I hope you can all see that.
And I know that Stephen will know what this is, but perhaps some of the others won’t,
so I'm going to explain this and why it's so special.
This is a Broomrape. It's scientific name is Orobanche.
And in this case, it's called Orobanche Picridis, and it's very rare.
So this is the plant we're looking at, this sort of ivory coloured one, and it's a parasitic plant.
So it's parasitising this green plant here. And this one has no chlorophyll of its own.
And the reason I thought Stephen might like to see this is because some years ago, Stephen, Simon Hiscock and I did some work,
some research examining particularly the genetic structure of populations of these plants, and our work
was showing that these parasitic plants are actually in the process of forming new species on different host plants.
In this case, this one is growing on a Hawkweed.
But they grow on different things and they become isolated on different host plants that grow in different places,
and this is a barrier to them sharing genes. And then over time, they become separated, and they evolve new species.
And that's what some of our work show. But that's a plant that doesn't feature typically in botanic gardens.
It's often been ignored by conservationists. And so we're really excited to be able to grow plants like that.
And I'll just finish my answer to that question by saying that there's a related
plant to this that I can't show you because we're not able to grow it yet.
But it's a plant called Cistanche that grows from the Middle East eastward to China.
And it looks a bit like that, but huge. It's really, really big, robust looking plant that grows in the deserts.
And we're doing a project together with scientists at the University of Reading and also in China as well,
to examine the relatedness of these complicated plants.
And we look at both living specimens and herbarium specimens, just like the one Stephen was showing,
pressed specimens, which have enormous value in terms of looking at what we call type specimens, the true first one
that is linked to the description of a species. And so we look at those as well as the living representatives.
And it's really important that we do.
And I can give an example of an application, this parasitic plant that I've described, it can grow on plants called Saxaul and Tamarisk,
which are being planted currently across the world's deserts to halt land degradation, which is a major global crisis, actually.
And if we can grow the Cistanche linked to those plantations, that's really exciting because Cistanche is potentially a famine food and a crop,
it's used widely for herbal medicine.
And if we grow it in a controlled way, it means that people no longer have to harvest them potentially illegally from rare wild populations.
So there's a conservation aspect too and all of that comes from examining the herbarium specimens like the one Stephen showed.
So sometimes these dried specimens, there's a lot more to it, I think, than necessarily meets the eye.
Thank you very much. That really helps make the connexion between the herbarium that Stephen was talking about and your kind of living collection.
We’ve got a moment or two for questions. And if any attendees would like to pose a question in the Q&A, please do.
And we've got briefly one, just asking again for the Latin name,
I think it was the first plant you showed from the biodiversity hotspots in Japan.
Yes, I'll say it and we can share the name after, but it's Aristolochia zollingeriana.
Thank you very much. So if anyone else has a question, please do write it in the Q&A.
So do you, I
was just going to ask Chris, are you actively using the herbaria that Stephen kind of looks after, and others in the collection
when you doing your research or looking at when you're growing new species and so on?
Very much so. And Stephen and I see one another regularly, more online now than before,
but that we very much see the collections as linked and actually I'd say inseparable.
You probably agree, Stephen? Yes, I would. And as of course, in the 19th century,
Charles Daubeny, when he revitalised the garden after a century or so of decline,
one of his big points was the fact that the living collections and, if you like,
the dead collections I look after, they complement each other.
So there are things that you can do with the living collections that you can't do with the dead collections and vice versa.
But together there's this great synergy between them.
The other thing that I think is really exciting on that point, as well as your question, is that the advances in technology
is such that extracting and using DNA from dried specimens is so much more feasible than it once was.
And that's opened up a whole world of possibilities.
Yes, so from our collections, we have had people being able to extract DNA from samples that are well over 300 years old.
It's amazing.
Thank you, so we've had a couple more questions come in and we've got about a minute or so just before we move on to our very exciting next item.
So firstly, there's a question about the parasitic plant.
Did you suggest then that it will develop into a completely different species if the host plant is changed?
And that's amazing. So what kind of causes that transition into a new host species?
So, yes, I'll explain more. So these parasitic plants can sometimes look very similar because they lack, for example, leaves.
So botanists have been deprived of some of the characteristics we might usually use to tease apart species.
So if we imagine you could have two different populations and they look the same,
you might have one that is growing on clovers in a field, you might have another that grows on sea carrots on a sea cliff.
And because of the different ecologies of those two different hosts and the fact that another dimension I didn't mention,
but in some cases they are self-pollinating and that means that there's a lack of genes being exchanged between those populations.
And over a period of evolutionary time,
they become physiologically adapted to those different hosts and different environments and they become genetically differentiated.
And so they're on the path to new species. And I think sometimes we think of species in a very fixed way.
But of course, speciation, the formation of new species, is a process.
And so perhaps what we're looking at here is something that's in that process,
what we call incipient speciation, is on the way to become a new species.
That makes sense. Thank you. And then one practical question.
What procedures are used for transporting plants across borders?
So certainly with the dead material,
there's a lot of rules and regulations about what we can move,
how we can move material, what we can do with it when it arrives,
what sort of sanitary procedures that we have to go through in order to make it safe.
And this type of thing, in fact, probably far,
far more procedures are associated with the way that we move material inside the herbarium collection
and probably also in the Botanic Gardens and the way that people move material between gardens and in,
if you like, in real life. Thank you, we've had a comment just that biodiversity hotspots are not a new concept.
And one of our attendees remembers references to centres of creation being used in the early 1830s.
So I don’t know if that's a very early equivalent. Thank you.
I think we'll move on to our next item, so we'll bring this up on the screen.
And so this is a very beautiful illustration. So, Chris, could you tell us a little bit about this plant and why you've chosen to share it today please?
I can. I think it has a sort of curious beauty to it.
And I'm sure that many of our listeners will, even if they don't know the exact species, they'll recognise the form that this plant takes,
because I'm sure many people be familiar with either some of the native relatives that
grow in our hedgerows or indeed some of the cut flowers that we buy in from florists.
This is a type of Aroid, which is a name that we use to describe plants in the family Araceae or the Arum family,
which is a very large family, plant family, of over three thousand species, particularly in the New World tropics,
but they're found all over the world. And the reason they're very familiar is because they have this distinctive floral structure.
So what we're looking at, all of that purplish bit in the middle that we might be tempted to call a
flower, from a botanical point of view is not quite accurate because that isn't a single flower.
And so I'll break it down into parts. So that slightly spotted purple structure is what we call a spathe.
It's a sort of leafy sheath-like structure. And then the blackish spike poking out is a spadix or spadix and the blackish part is an appendix.
And at the base of it, if you if you look at that part on the right, the true flowers are clustered around the base.
And so if we work our way up from the bottom of that spike-like structure, those creamy little flowers at the bottom, those are the female flowers.
And then there's a ring of sterile ones, which look like spines. Then you've got a purplish band of the male flowers and then some more sterile spines.
So those are the flowers. And you'll notice they're separated, the sexes, but they're also separated in time as well as space.
And I'll explain a bit about what that means. But before I do, I'll say that many of these Aroids smell very unpleasant.
So we tend to think of pollination as flowers that smell lovely and attract bees and
bees get nectar and everyone's happy. Pollination sometimes works a bit differently.
So there's a phenomenon called sapromyophily where flowers mimic something decomposing to attract, for example, flies to pollinate them.
And the flies are duped into thinking that they found something to lay their eggs on, for example, or to feed on.
And they pick up and spread pollen to the plant. But there's no reward for the flies whatsoever.
Now, in this case, this plant, which I realise I haven't told the name of yet, is Arum Dioscoridis.
And it grows in the eastern Mediterranean. And you find this in Cyprus, Turkey, Rhodes, Syria, Israel, Palestine.
And it smells of manure and it attracts little midges.
The blackish appendix actually heats up to emanate this cow dung-like smell and the little midges, they crawl into that green pouch-like chamber.
And if you were to cut that in half, you'd see that it was a hollow chamber in which the flowers that we just talked about,
they grow in that chamber and these midges become trapped in this floral sort of prison cell, if you will.
And if they visited another Arum before this,
they will they will distribute pollen around those female flowers and half the job is done because it's pollinated.
And then I mentioned a time switch. So what happens
overnight is that the female flowers shut off their receptivity and then the male flowers shed their pollen,
and then these midges are released by withering hairs the following day and they fly off and do the whole thing again.
So that's how it's cross pollinated. And if we pan to the next slide
there are some whopping examples.
So this unusual looking plant, this is called Amorphophallus konjac, and it's really quite enormous, actually.
I'm not sure you can see from the scale on my photo but this was growing in our nursery houses a few months ago here at the Botanic Garden.
And this is one that smells like rotting meat to attract flies. And I promise you, it does.
It's just as well we have face coverings at the moment, I'll tell you! And then on the next slide, there's another one.
So we go on one more.
And that one, yeah. This is Helicodiceros muscivorus, but it's commonly called the dead horse arum, which is a misnomer.
It should be called the dead gull arum, because it smells like dead gulls.
And I'll just finish my answer to this question by saying that we do research,
we carry out research on our living collections with other scientists here at the university.
So we're working with, for example, Professor James McCullough in the Chemistry Department and Luciana Carvalho, his student.
And we've been examining some of the compounds that these structures produce to understand more about the chemistry of these strange odours.
And we found all sorts of unusual things. Dimethyl disulphide, which smells revolting, but also beta-pinene, which has a nice pine-like smell.
There is a whole cocktail of different chemicals in this chemical signature that these plants are producing.
And perhaps on another occasion, in another talk, I can explain a bit more about why we're doing that, but they're fascinating plants.
And actually, sorry if we go back again to the painting, because I think in a moment,
Stephen is going to tell us a bit more about the painting itself, because I think you'll agree
it's very beautiful. And I'll just say that I was pointing out some very minute structures on there.
And I think Stephen's going to tell us a bit more about that.
But what I will say is it belongs to the Flora Graeca.
And it's fair to say, isn't it, Stephen, that this is being described as amongst the most magnificent Floras ever written?
Absolutely. So you're quite right.
This is an image, it's a watercolour, in fact, by Ferdinand Bauer.
So we go back to the prints, though, and I suppose to put that in context, it's useful to think about, well, why was it made?
What was it? What was the purpose of producing this watercolour?
It wasn't there to produce a pretty picture but for scientific purpose.
So and this was part, this was a result of an expedition and it was an expedition that
was planned by one of the Professors of Botany here, John Sibthorp,
who was the third Sherardian Professor. And John’s justification for going on this expedition to the eastern Mediterranean
was that ultimately he wants to be famous. That was basically what he said.
And at that stage, to be famous as a botanist, one way was to go and explore a part of the world that was very poorly known botanically.
He was also interested in the medicinal plants that came from that area,
and in particular the medicinal plants that were contained within a book that was
produced, or a manuscript that was produced, in the first century A.D. called De Materia Medica,
and it was written by Dioscorides, a Greco-Roman physician.
And in fact, that's who this plant is named after.
And that book, that manuscript became a total, if you like, of medicinal knowledge about plants for fifteen hundred years.
And people were discussing and arguing about what plants he was actually referring to.
And there are tomes and tomes about discussions about these plants.
And Sibthorp had the idea that the best way to find these plants is actually to go into the
eastern Mediterranean where Dioscorides worked and to see what he could find.
And this is what he did. So he was based in Vienna
at this stage. He had access to the best extant manuscript Dioscorides that is known.
And it was in the Imperial Library. And he also got copies of all of the illustrations in it.
He also was introduced to an artist and that artist was Ferdinand Bauer and Ferdinand Bauer and
his brother Frans have been described as probably the best botanical artists who ever lived.
And they started out on this expedition in March, 1786,
and they basically went from Vienna to Trieste down the spine of Italy through the Straits of Messina.
And then at that point, they entered this world where botanically it was very poorly known.
And so they explored Crete, they went across to the Aegean islands.
They went into Turkey. They over wintered in Constantinople. They came down the Dardanelles.
They then went down to Cyprus, did the first botanical exploration of Cyprus, went back across the Aegean,
and then were collecting plants in Greece as well.
And so they were collecting herbarium specimens. And we have Sibthorp’s
herbarium collections, they were also collecting and antiquities and rocks and animals and all sorts of things.
And Bauer was actually also sketching.
And what you see in front of you now is one of Bauer’s sketches.
We've got hundreds of sheets of Bauer sketches. And he worked,
he only made sketches in the field. He didn't do any painting.
So he made these sketches. And you see they are rather beautiful but you see lots and lots of numbers around them.
Those numbers correspond to colours. And so when they came back in 1787, Bauer started work.
At the end of 1787 Bauer started transforming these sketches, these pencil sketches with their numbers into the watercolours that you've seen.
And he did that transformation actually in Cowley House, which is Sibthorp’s house,
now part of St Hilda's college.
And he did nine hundred and sixty-six of these watercolours.
They're all folio size. They are amazing,
in fact, as watercolours. And he took on average, about one and a quarter days to do each one, a phenomenal rate of work and of quality.
And if we can go back to that, the watercolour image, what you will see is that he has this thing.
Bauer is really good on detail.
So the flowers that Chris was talking about, they have
a huge amount of detail there, and they are absolutely exquisite.
He was less good when it comes to covering large areas of surface with paint.
So he's less good, for example, on the spathe to put the purple spotting.
But when you get down to the absolute detail, it's amazing.
The detail is there. And Sibthorp dies in 1796 and Bauer doesn't work for Sibthorp for very long.
And yet you start to see some of that detail in there.
It's absolutely gorgeous work. And Bauer stops working for Sibthorp in 1792.
They really don't get on with each other. And Sibthorp dies in 1796.
When he dies, he leaves a will. And in that will he wants all of Bauer’s work plus his own notes and
everything to be to be published in this thing that he wants to call the Flora Graeca.
It becomes a nightmare, essentially, for the editors, because Sibthorp is, and what we can see here is just some of those images,
some of the additional watercolours, bits of the watercolours that Bauer was producing.
So the executors of the will hand on to the editor
nine hundred and sixty-six of these unlabelled watercolours.
You've got hundreds of pages of sketches. You've got thousands of herbarium specimens all unlabelled.
You've got Sibthorp’s diaries, and Sibthorp’s handwriting is awful.
To try and translate and produce this thing to become the Flora Graeca and eventually the Flora Graeca is published.
And the images are published in sets of 50 between 1860 and 1840, a really huge project.
And if you have wanted to buy a copy of the Flora Graeca in a complete set in 1840,
you would have paid about six hundred and twenty pounds.
To put that in context, the average wage at that period was thirty-nine pounds a year.
It was enormously expensive and in fact only twenty-five copies of it were produced.
Sibthorp wanted to be famous and he wanted to be famous for his science In fact,
what happens is because the volume took so long to produce, it was so expensive,
there were so few copies, it becomes, in fact, almost a work of art.
It becomes and it's Bauer who becomes famous associated with the Flora Graeca.
It’s not really Sibthorp and the science that was conducted,
but that doesn't detract from the sheer quality of these images.
And when you see a published copy of the Flora Graeca,
A published copy of the Flora Graeca is the absolute pinnacle of natural history illustration in the UK publishing at the time.
But it's still doesn't have the same quality as when you compare it against the original
watercolours. We are just extremely lucky to have the original watercolours for these images.
And then the Flora Graeca is on display in Roots and Seeds, so if people want to see it, it is well worth looking at.
Then I think we were going to talk about the living collection of plants at the Gardens Stephen
Yeah. So, yeah.
So one of the things obviously that I didn't mention with Sibthorp was that it wasn't just the dried material that he was collecting.
He was also collecting seed material to bring back to the Gardens and what he wanted to do with the Gardens,
which, of course, was to grow some of this material. And he grows a little bit of this material, but it doesn't really survive very long.
But I think, Chris, that Gardens are going to have a better go at it.
Stephen, so I'm sure many of our listeners will be familiar with this part of the Botanic Gardens.
This is in our lower garden. The photograph we're looking at to the moment is, is the Rock Garden.
And the Rock Garden was first constructed in the 1920s.
And it's been redesigned a number of times. And it had quite an eclectic collection of plants growing in it a couple of years ago.
And what we've been busy doing and the team here in the last couple of years particularly,
is reconfiguring the rock garden and replanting it with a Mediterranean-themed flora inspired by the very work that Stephen has just been talking about.
And what we really wanted to do here was to create a living representation of the Flora
Graeca, to bring some of this literally to life, in a way, for our visitors.
And so what we've done is we've planted the rock garden out with new plants inspired by those that are featured and illustrated in the Flora Graeca.
And this gives people an opportunity to walk through it. And there's a there's a geographical theme as well.
So we've loosely divided the areas of the Rock Garden into, for example, mainland Greece, Turkey, Cyprus and Crete.
And it really was quite beautiful, actually, this summer.
So what you're looking at there is a photograph of some tulips from Crete.
That's Tulipa saxatilis. Stephen, does that particular species feature in the Flora Graeca?
No, it doesn't. No, it doesn't. OK, so not the best example for me to highlight.
But it is actually from that part of the world. And it's a beautiful living collection.
And it's also a very sensory experience, I think, because there's something about the Mediterranean flora that you can hear it.
It buzzes with crickets on a warm day.
You can smell it. Certainly there are lots of aromatic oils that volatilise under the sun.
And particularly we've got some gum cistus and things like that.
You can really smell it. And it's sort of bespangled with splashes of yellow and purple at the relevant time of year.
So it's a small part of the garden, but it's one that the team have worked very hard on and we're very proud of.
And I do recommend for people to come and see it and experience it.
Thank you. I think we've got a close-up of that beautiful tulip so that we can look at that and we'll take another few moments
for questions now, so we've got an attendee asking about whether they're any good mobile applications you can
recommend to identify plants when you're going around the Botanic Garden or anywhere,
really, if there's any good plant identification apps that you know of.
I'm afraid I can't at all because I don't use them.
But what I can say is that I am prepared to admit that I was sceptical about them.
But a couple of times when I've been giving a tour or showing people, they've sort of in a light-hearted way tested me against the app.
And I've never known for the app to be wrong.
So, I think depending on what it is you're looking at and how complicated, I believe they can be quite effective.
Actually, I'm afraid I've never used one and I suspect without speaking for Stephen that he hasn't either.
So I'm not sure we’re best placed to advise that one. No, I guess you didn't need to, but it's good to know that they're accurate.
And we've had a question about tangentially about the Herbarium and the Flora Graeca,
about the kind of paper that they're made of and how expensive it would be to produce and with the materials that they are made of.
And then as a secondary question. Were the watercolour paints plant-based?
So what was the actual paint made out of as well as the paper?
They are really, really interesting questions. So starting with the something with the Bobart paper.
So most of the paper gone into producing the Bobart paper is either French or Dutch in origin.
And it's very high-quality paper. It's a rag-based paper and it would have been very expensive.
So there's a huge financial investment in that volume at the time.
And of course, from the point of view today, it's beautiful paper because it's essentially acid-free, which is a problem
we have later on with some of the papers that we used. The papers end up eating away at the specimens and everything.
But we don't have that problem with the Bobart collection.
The papers that were used in the Flora Graeca are in fact Whatman papers.
And again, it's really interesting looking at the watermark dates for the paper against the publication date.
And what we can see when we do that analysis is in fact that that there must in very early stages have been a problem with
the run because there's a whole load of the images that are in fact on paper that post-dates the publication date.
So they must have been replaced.
And in fact, if we look at the accounts and we do have the accounts, really, sadly, we can see that sort of being slipped into the accounts,
that replacement. The paper that was used for the sketches of Bauer’s are different
again. He was picking up paper as he went around.
And so you can actually track where they were when they were picking up blocks of paper.
So they essentially picked up blocks of paper, if I remember rightly, from five different sources.
So an Italian source, a Greek source, and then there's also, if I remember rightly, two Turkish
as well. And the other question was about the paint, were they plant-based? Well, some of them, some of them were.
One of the things that we found by doing research in collaboration with the Bodleian
is that we've been able to work out essentially the pallet that Bauer was using.
And that pallet is tiny.
He had about eight or nine pigments that he was using in order to create the full spectrum of colours that he was using.
And in the case of the plants, it’s about 300-odd different colours that he's creating.
But most of those pigments are, in fact, they're not plant-based.
One of the blues that he's using is indigo, which is, of course, is plant-based.
But that's about it. Thank you very much.
So I think we'll move on now to our final item, so we're going to show a photograph.
And Stephen, could you tell us about this rather curious looking building and what was it built for?
Right. And so this is a photograph that was taken in the late 19th, probably very early 20th century.
We don't know exactly. But what it is, it's the second incarnation of the Lily House and any of you that know the Botanic Gardens,
I'm sure will know the Lily House and this concrete pond that's in the middle of the building.
And the Lily House was constructed in the very early 1850s and it was constructed for one purpose.
And that purpose was to grow, in fact,
the great show-off lily of the period which was the Amazon water lily and the Amazon water lily was this thing that was being discovered
at the beginning of the 19th century in North and South America and had become this thing that people wanted to grow in the big gardens,
wanted to grow in the UK. And the race was won, in fact, by Joseph Paxton at Chatsworth in 1849 when he got it to come to flower successfully.
And it caused a sensation and Daubeny saw this and he wanted to grow it in Oxford.
And in order to grow it, he had to reconfigure the Gardens and they had to be able to construct glass houses
and they had to be able to maintain water at a constant temperature. To do that
he constructed this concrete pond and
initially, he started off by growing only the Amazon water lily, and he charged people to come and see it in his glasshouse,
and if you made the conversions, it's roughly about the same cost of getting into the Gardens today.
And people complained about it, but he soon stopped growing it because he decided, in fact, that it was a waste of space.
There's this plant with these enormous leaves, metre-wide leaves.
I’m sure Chris is going to talk a little more about them in a moment.
And they were covering the surface of this and he decided that what he wanted to do was to actually grow a greater diversity of water lilies.
So we have here a very large diversity of water lilies being grown, probably, in fact, a much greater diversity than is growing today in the Gardens.
But other aspects of the planting, look rather familiar, but the
water lily, the pond itself proved to be a bit of a problem for Daubeny. Got his plant growing beautifully,
great sensation, but given the location of the pond,
it was continually subsiding and he was pouring large amounts of money to underpin the foundations of this.
And in fact, he ended up using his own money to underpin the foundations of this pond to stop it slipping into the river.
And but at least it stopped doing that, that day.
So that's what the building that we see in front of us.
Fantastic, thank you. So. Yes. Chris, could you tell us a little bit more about the plants that are grown in the glasshouses today?
So what are they used for and why are they important?
I can and before I do, I'd love to actually highlight that in some respects it's not so different.
I can recognise plants in this very photograph that Stephen and I know grow in that same pond and around it today.
So just on the left for the first time since, actually, I think I can discern Nelumbo nucifera, it looks to me,
which is the sacred lotus. We've got Nymphaea water lilies filling the pool itself, which we still grow today.
And this papyrus, which grows about three metres from where it is now,
around the same pond and bananas and gingers and various other things in this photograph, which you can find growing in this exact location.
So it's really wonderful, actually, to be looking at this photograph.
Your question, Helen, was about what we grow today and sort of linked to the answer to the first question I gave.
We grow plants from all around the world for conservation teaching purposes, but also for research purposes as well.
And is it the next, what's the next photograph, the next dramatic image of the year?
So we've got build up to that. There we go. I couldn't remember when it was coming.
So this this is the underside of the giant Amazonian water lily that Stephen was referring to.
And it has an archetypal beauty. And so much so that the night that I can say that when our horticulturist take these leaves out,
which is quite regularly during the growing season, because they fill the pool so quickly that we have to remove them.
And when we do and we flip them over, I've had visitors gasp at the beauty of the underside because they don't expect it to look quite like this.
It's a wonderful structure. Yesterday we had a seminar in the garden and I put one in a paddling pool to show people the weight that they can
hold because people will possibly have seen or read that these giant leaves can sustain the weight of a small child.
And I think people think in an era of manipulated digital imagery that it's not true.
But I can promise you that it is, because people's toddlers from the Botanic Garden have been sat on these leaves, and yesterday to prove the point,
using a rather small leaf, but by these standards, it was about a metre across.
And we put in the paddling pool and I put one kilogram bags of sugar on it and we reached six and comfortably because that's all I had,
because I didn't want to clear out the local Sainsbury's of people’s sugar.
But I'm sure that we could at least get up to seven and a half, seven and a half or eight,
which we've done before, which is the weight of two newborn babies. And that's on a relatively small leaf.
So these are incredibly strong. And your question, Helen, was how are these plants used today?
And I work, in an area of my research, which is quite new to me, actually is interdisciplinary.
And I work with, what that means is I work with scientists from other disciplines, in this case physicists.
And I've shown some physicist friends of mine around the Botanic Garden.
And they asked me, how does this leaf work as they'll ask me with so many plants
And I told them what I knew, which wasn't a lot. And I said, I'm sure people understand more.
And to my astonishment, very little have been done on these to understand how and why these leaves grow so large.
And so we set out to tackle answering that very question, using mathematical modelling and experiments to understand the load bearing capacity.
And what I can say is that this giant structure is an economy of material.
It's a very small amount of biomass for very large amount of surface area.
And so what we think is happening here is that this water lily that grows in rapidly drying pools around the Amazon.
It doesn't necessarily go in the Amazon proper. It's in areas which are seasonally drying.
It has to grow very quickly. Hence we take leaves out to give it room and it occupies the complete area of the water and out-competes the other
plants to maximise it’s surface area for photosynthesis at a low cost because it’s a small amount of biomass.
So, and this has potential applications where you might want to cover a large
surface area with a small amount of material, floating solar panel for example.
And have I got time, Helen, to show you one more plant?
Of course, if you've got a live specimen, that would be brilliant. Yeah, a really beautiful one, actually.
I just wanted to show you, and I'm sure some will be familiar with this, it's a Nepenthes pitcher plant.
It is a carnivore. So this is a leafy trap.
So this is a modified leaf, from an evolutionary point of view, that has become fused.
It's evolved from something similar to a sundew, we think, if our listeners are familiar with those, and again,
we've worked to, we've examined this structure more closely, I think you could see that it's got ridges on it.
It's got quite a rough surface. This surface is super hydrophilic, so water sits on it.
It forms a lubricating film and insects aquaplane off it
down into the trap where they are caught and supply the plant with nitrogen.
And we wanted to examine in a little more detail how this structure works.
And so we, with my colleagues, they created soft polymer replicas of this surface and did some fancy mathematical modelling.
And we also examined insects and foreign droplets, i.e. oils travelling on the surface.
And together,
this body of work showed that things move on this surface in a way that is a lot more controlled and a lot less arbitrary than you might suppose.
So even at shallow angles, you can control with, with very fine precision how something moves along these railings.
I think it is analogous to whatever they call those strips that if you do tenpin bowling, keep the ball going in in the same direction.
I was never very good at that. But it's a bit like those.
So it drives things in.
And so from an evolutionary biology point of view, that's fascinating because it suggests that insects don't just randomly slide off.
They’re driven in a controlled way into the trap. From an applied point of view
this has applications in, for example, microfluidic technology.
So any technology in which you might want to move small amounts of fluid around with precision,
for example, in an inkjet printer or something like that. So there's a lot to learn from these plants.
Thank you so much. And we're coming towards the end.
So I just wonder if we could finish with both of you telling us a little bit about the relevance and importance of plant collections,
both held in Herbaria and in Botanic Gardens today. So then, Stephen, if you want to start us off.
Yeah. So I
started with a quote from an academic at the beginning of the 18th century who
described the collection I look at as a gathering of the refuse of nature,
and that was Joseph Addison and of course one superficial view of that is just you've got this huge pile of dried plants and what use is it?
Well, importantly, as I've said earlier, you've got information associated with that.
You've got data associated with that. You've got a fundamental level where and when something was collected.
And so, if you like, a herbarium and it's not just us, but it's this an international network of collections at two thousand five hundred worldwide.
We all talk to each other. There's a sort of database that allows us to move back in time.
And that's a really important way of thinking about how you might use this collection.
So it's not just the collection that is traditionally associated with plant biologists, plant taxonomists to name and describes things.
There's a whole range of different people who are now starting to use the collections and think about how to use the collections.
So in the collections in Oxford, we've got geologists, we've got archaeologists, we've got engineers, we've got philosophers.
We've got
English academics, we've got historians, obviously zoologist and plant biologists all using these collections in all sorts of different ways.
And the limit really on the use of the collections is well, obviously the sorts of material we have.
But in many ways, it's the imagination of the individuals who are thinking about using these collections for
in fact, both teaching research and public engagement, because as you've seen,
some of these objects are really an incredibly engaging as a physical object.
And I hope that's one of the things that comes across in the exhibition is how engaging these objects are in terms of public engagement.
But they are an active teaching and research resource as well.
Thank you, and Chris if you want to add to that. Now, so wonderful answer,
and I suppose I'll just say that from the living plants point of view, of the four hundred thousand or so vascular plants, that the different types of
plants that grow on our planet, there are like a living library for scientists to explore.
And one of the wonderful things about Botanic Gardens is that we grow quite
a diverse assortment of those from across groups and around the world.
And one of the things I've enjoyed about this discussion and that I hope that it's
come across is that the strong bond between living collections and the dried, or pressed,
the dead collections in the herbaria. And that's important as we describe new species.
We're quite reliant on herbarium specimens to inform that process.
And that's important from the point of view of conservation as well,
because at a time that new species are still being scientifically named all the time,
others are edging towards extinction and losing the fight against the threats that they face.
And so I think there's an urgency for botanists to quantify and understand what's there so that we can conserve adequately.
And you need herbarium collections to do that.
And I think also for collections, whether living or dried, building on Stephen's point there,
to engage people and to bring plants into focus. I think we have a harder time doing that than animal biologists.
Generally people, particularly young people, we know they identify more with animals.
And perhaps because we all have a sort of anthropocentric zoo-centric view of the world because we are animals.
And so I think we need to think of plants as something other than a pretty backdrop against which animals exist.
And so I'm interested, as Stephen is, in finding ways that we can inspire and engage people with plants, plant science, plant biology,
so that we can start to foster a greater care and awareness of the importance of plants, because we need to as a human population.
Thank you both very much. I certainly think today would have inspired and engaged our attendees to spread the word about this
because I think, as you say, it's very, very important. Thank you.
We've got about, if people are happy to hold on for a minute or two, we've got a couple of questions still waiting.
And if anyone has one to add, do just pop into the Q&A now
But the two questions we've got relate to the specimens that you were talking about, Chris, from the water lily house.
So the first was about what would be the evolutionary advantage of being able to hold as
much weight as an Amazonian water lily can, why would these plants have evolved in that way?
Yeah, great, great question. I like that a lot.
And we thought about that very question, too.
So I think from an indirect point of view that the structure is also linked intrinsically to its size.
So in order to grow that big, you have to be strong.
And the reason you'd want to grow that big is to maximise your surface area for photosynthesis and keep other plants out.
So I think that's probably first and foremost. I think there's perhaps a secondary point to make around wading birds, for example.
So we thought about what is the habitat that this extraordinary plant grows in and it has to cope with wading birds,
but it also has to cope with flash flooding. And water is heavy.
What you can't see from this photograph is that there's a raised rim around the leaf and at one point
there's a sort of slit in it that we call a sinus and that allows rapid drainage of the leaf as well.
So it's an extraordinary sort of multipurpose leaf that works and functions in an astonishing way.
Very, very interesting question. Thank you. Thank you. And then the second question relates to the last plant that you held up for us,
and I'm probably going to pronounce this wrong, but does a Nepenthes release enzymes inside the pitcher to digest the flies?
If yes. what is it? Yeah, you know, I, I get asked this question a fair amount.
I wonder if the person asked me is a biologist from a different discipline because often they are. The answer is yes.
And so this is a newly opened one. This one's been open quite a while and
I can probably actually, just there are some digestive juices that you might see pouring out into the Botanic Garden Library.
Yes, they contain digestive enzymes which break down the insects that they catch to an extent,
particularly to release nitrogen, to a lesser extent probably phosphorous to feed the plants.
The suite of enzymes is enormous.
So I'm not a plant biochemist. I can tell you that there are chitinases, for example, that break down the hard chitin parts of insect exoskeletons.
There's a whole range of enzymes. And actually with Renea Antonet, the Department of Plant Sciences,
we actually sought to try and understand a bit more about those enzymes and what they are and how they work.
But it was quite difficult, actually, to do.
And so we didn't perhaps get the results that we wanted in that project, but we were interested in that.
So, yes, we can think of it as acting a little bit like a plant stomach in a way.
Brilliant, thank you.
And one's just come in. Would the larger surface area of the water lilies also help to reduce evaporation if the water it’s growing in might dry up.
So could it have been adapted to cope with less water?
Yes and no. So if the water dries up, the plants will die.
So it's a no, it can't cope with that at all, actually.
But in a sense, the way I see it, the reason I say yes or no is because that is actually part of the cycle of the plant.
So it doesn't grow in nature as a long-lived perennial.
It actually has a short life history, which is perhaps surprising when you look at it.
It grows very, very rapidly. And then the habitat it grows in often will dry seasonally and then the plant dies and then the whole thing starts again.
And actually that's how we grow it here incidentally because we can't sustain the
light levels that it needs to throw out those enormous leaves all the time.
So we grow it as an annual here at the Botanic Garden. Thank you.
And then we had a question, do you maintain seed banks for threatened species at the Botanic Garden?
Yes, we do hold seeds and we don't have an extensive seed bank and we don't have the facilities to keep large amounts of seeds,
so it's not something I'd say we do, we do well. We do keep seed particularly linked to,
so, for example, that plant that I showed you earlier. We’ll be collecting seed of that and we'll be sticking it in the
fridge and we'll be making sure that we keep it on a rotation so that we can keep on regrowing it.
So we do we do hold seeds. But what we tend to actually do is work with partners who have the facilities to be able to do it really well.
And so, for example, for some of the projects that Stephen and Ben Jones, the operator and others and I work on,
we might collect seeds from a given plant and we deposit those seeds in the
Millennium Seed Bank with the partners with whom we work and work in that way.
Good question. Thank you very much. So I think we're going to unfortunately have to end then due to time.
But thank you very much to everyone for joining us today. And it's been a real pleasure to connect with friends of the Bodleian from all over the world.
We've had people from all over different countries today and kind of share your enthusiasm with them.
Thank you so much to Stephen Harris and Chris Thorogood and the behind the scenes technical team as well, Karen,
Rebecca, and Neil. Please do look out, everyone, for an email with a link to the recording of the session.
And please take a moment to fill out the questionnaire when that link comes through to you.
And it's also in the emails that you had for booking. Do sign up to the Bodleian newsletter to find out more about upcoming events.
And do you come and see the Roots to Seeds exhibition and visit at the Botanic Garden and Arboretum
if you haven't already done so, and you're able to. And we hope to see you all again soon.
So thank you very much. And have a good evening. Thank you.