WATER SOUND On a cold winter day in New York City, I watched a video taken by one of our researchers from a recent fieldwork trip to Panama. MORE WATER SOUND ANA: I am Ana Maria Bedoya. I'm an assistant curator at the Center for Biodiversity and Evolution at the New York Botanical Garden The video opens on a small waterfall. Despite its size, the sound of the water is deafening as it rushes downstream towards the camera. ANA: Just imagine. The sound of the strength of the force of the water running, running, running. If you've been to the Colorado River, the rapids is something like this. SOUND OF DUNKING The camera dives under the water�s surface, and there appears a row of leafy green plants, somehow tethered to a rock in the fast moving current. A jackpot for Ana and her research. ANA: I've coined the term extreme botany to talk about the work that I do. I work with plants that are in extreme ecosystems like river rapids and waterfalls. Most of us probably haven�t willingly immersed ourselves in river rapids, but if you have, you�d know how hard it is to stay in one place. Impossible, even. And yet here are these plants, not only staying in one place, but thriving. ANA: To live in these conditions, they had to modify extremely. And it's not just the plants that are doing something extreme. Ana took a plane, a boat, and hiked for hours just to reach these plants. And now she too must stay put against the forces of the rapids. ANA: So it's extreme conditions that the plant needs to do. So we have to engage in extreme activities to get to where these extreme plants are. Welcome to Plant People. I'm Jennifer Bernstein, CEO & The William C. Steere Sr. President at the New York Botanical Garden. In this episode: Extreme aquatic plants, the people who study them, and what they can tell us about the origins of our world. JENNIFER: Anna Maria. Welcome. I'm so thrilled that you're here on the podcast and at NYBG. And I want to start with the question of how did you become a plant person? ANA: Jennifer, thank you so much for having me. I'm really happy to talking to plant people. I think it's fair to say that I was born a plant person. People that know me from elementary school were saying that was making up names for plants in gardens when we were growing up. And I have these flashbacks when I was in high school of building these botanical garden models for the electronics or mechanics course and putting pumps to create waterfalls in the botanical garden. So I think there was this natural love for plants. And I was just very impressed by the natural world as I was growing up. And so these passion for plants led me to then wanting to study biology. It was because of plants that I chose that career and the higher education system in Colombia, where I'm from, is different from the United States. So in here you go to college and then major. But in Colombia, you have to decide which career you're going to go to right from the start. And so I decided to go to biology. And then I was seeking calculus one and two, not related to plants. I was taking physical chemistry, analytical chemistry, biochemistry, and all these things because I wanted to study plants. I think it was a huge privilege to have been born in Colombia and have been trained as a botanist in Colombia, because I was learning about plant diversity, as I was going to incredibly remote places with unique plants. And so I was learning about plant diversity in one of the most remote and most biodiverse places on Earth. JENNIFER: Yeah. So speaking of interesting plants, most botanists stick to dry land, but you study aquatic plants. How did they become your focus and what is it about them that is so special? ANA: There's a British botanist that I often cite; he published a book in 1974 called, Water Plants of the World. And among the first pages, I read a quote from him that says, �botanists don't like to get their feet wet.� Because we know more about terrestrial plants than about aquatic plants. And think about it, when we're walking here in New York City and we see a pothole, we try to avoid that pothole because having our feet wet is uncomfortable. But, the same applies to being in the field. And as a result, botanical collections lack, in general, representation of aquatic plants. But when I was doing my master's in Colombia, I encountered this incredible opportunity. I was invited by my mentor at the time. He had secured funding for a project aiming to inventory the aquatic flora of the third largest drainage basin in the world by water discharge. This is the Orinoco Drainage Basin. And one quarter of that drainage basin is in Colombia. JENNIFER: So for the listener, what is a drainage basin? ANA: A drainage basin is a system of rivers that all drain to the same major river. So the Orinoco drainage basin, that's the main river, the Orinoco, and then there's multiple rivers that would drain into the Orinoco. So the area of drainage of all these rivers that then end or give the waters to this main river is, that's what we call a drainage basin. JENNIFER: Sort of a confluence of different rivers. Yeah. And I'm sure a place of a lot of plant diversity. ANA: It definitely is. It looks like a wetland full of grass. So it looks like a very uniform ecosystem. But it really isn't. They're highly diverse and largely unexplored in terms of aquatic plants, because again, botanists don't like to get their feet wet. And so he came with a proposal of, would you like to travel to remote places for two years? Would you like to write a book about it? Would you like to learn about plants and then collect them and then build collections for herbaria? And so, of course I said yes. And so for two, three years, we were collecting plants in the field. I got to do horseback riding collecting, where we had water up onto our knees, even though we were on the horses. I got to fly a Cessna myself. I got to fly in DC3s, which are these low wing, metal monoplanes that you have cargo in between, and then the passengers are on the sides. It was the most incredible experience of my time as I was growing up as a botanist, yeah. JENNIFER: Yeah. What an incredible experience. So to do your research, you've had to really become a pioneer of what you call extreme botany. So, what is that and why is it a necessary part of doing your work? ANA: Yeah, I think there's this misconception that botany is not as extreme as zoology, maybe, because, you know, we're not chasing after monkeys, we're not chasing jaguars. And so botanists, we're not moving with our organisms, for the most part, but we're moving towards organisms. And so to get to where the plants are and plants like to be in extreme places. So they like to be on cliffs and places that not necessarily just need to walk to, but you have to take multiple planes and get a boat. And so I would say that botany as a whole is quite extreme. If you have people that study tall trees, they have to climb on the tree and then they use pole pruners, these long metal poles with clippers on the top to cut off branches. In my case, to get to where they are, I have to kayak. I have to raft. I've employed security systems, inspired by what firefighters do. And so with harnesses and carabiners, and I had to learn a lot about water rescue. And so, what is a tension diagonal? What is a dry treated rope? So that we can actually get inside of these rapids. JENNIFER: So have to get sort of into the rapid, you have to get underwater basically in order to find the plants. Is that right? ANA: Yes. That's, and, before I used to kayak and I used to raft to get to these places in many cases, but I decided that I wanted to not just pass by, but I wanted to get inside of the rapids, which is how I came up with this idea of seeing what firefighters are doing for rescuing people in the water and so that we can go safely inside of these rapids. Because safety really is a very key term in there. I tend to say fun field work is safe field work. And so how can we have the most fun getting into a rapids but doing it in a safe way? JENNIFER: So, okay, let's take us to one of these places. Can you describe a recent journey you took to the field. How did you get there? What did it look like when you arrived? What did you find, how did the whole thing feel? ANA: Yeah. I engaged in a field trip in January. I was in Panama with NYBG graduate students. SOUND OF A BOAT ANA: We flew into Panama City and then we took a boat and then we, navigated through the Caribbean Sea and then entered the rivers through the Caribbean Sea, because there's no way of getting access to the rivers, but only through the ocean. And so that's what we did. That was really fun. Huge waves, though. So it was a little scary, because I like freshwater better than saltwater, I should say. Um, but then what it looked like on a regular day for us is we would wake up really early. 5:30. Bird people wake up earlier. So that's nice. We don't have to chase birds, right? We're going towards our beautiful plants that are just there. JENNIFER: I mean, 5:30 is pretty early. ANA: Yes, it's early. I like waking up early. We just want to just to take as much advantage as we can, because it's the limited amount of time that we have there. And then, we would walk, say, three, four hours. So imagine this scenario. It's hot and humid. And then you're been walking for three, four hours in the understory. Walking, walking, walking, and all of a sudden all our view opens to this incredible hidden gem, which is a huge waterfall. WATER SOUND The sound of the of the water falling is just a complete paradise. And all the people in my team started jumping in the water. And because you're in the tropics, you're not in a temperate region. So the water actually feels quite nice. So everybody's just jumping and playing and it's a moment of happiness. And turns out that this waterfall is completely full of the plants that you were hoping to collect. And that's what happened to us. The feeling that I get is whatever is happening here happens every day, all the time. And that's what I want to learn about when I go back to NYBG in my office. And so it's really inspiring and great. JENNIFER: Yeah so, the kind of plants you�re finding, can you give us a couple of examples in this waterfall? What sort of plants were you collecting and how have they evolved to thrive in that kind of an environment? ANA: Yeah, so I work with aquatic plants in general, but my specialty is in a family called Podostemaceae. Commonly called riverweeds or, uh, orchids of the waterfall. JENNIFER: Orchids of the waterfall or riverweeds? ANA: Or riverweeds. I like riverweeds. JENNIFER:You like riverweeds better. I was just going to say I think orchids of the waterfall is very nice, but okay, riverweeds. ANA: That�s very nice. I understand the charm that orchids have, but these plants are so strange and interesting in different ways than orchids are, and so they're the only group of flowering plants in the neotropics, in tropical America, that live in River Rapids and waterfalls. To live in these conditions that are very extreme conditions, because it's fast moving water, they attach to rocks, supposedly with a biofilm of cyanobacteria. We don't know for sure, so there's research to do on this end. JENNIFER: So they're wearing sort of like an armor of cyanobacteria, is that it? ANA: At the base of the, of the thallus, and which is the other weird thing in these plants is we don't talk about roots, stems, and leaves. We talk about a thallus, and so they're flowering plants, but they look like lichens. They look like moss. They look like algae, but they have flowers. And so to collect these plants, because they're firmly attached to the rocks, one needs to use a knife to scrape the plants off the rock. Or sometimes we collect the rocks themselves. And actually, we have a really comprehensive and really nice rock collection here at the New York Botanical Garden. So they have extremely modified their morphology, so that they can withstand life in these extreme conditions. JENNIFER: So the attaching to the rock is one example of that. Are there other elements of their morphology that give you an indication of how they're thriving? ANA: One interesting thing about these plants is that they're restricted to tropical regions of the world. There's two seasons mostly in the tropics, the dry season and the wet season. So in the wet season when it's raining a lot, the plants are completely submerged and they're vegetative. So you'll see the leaves are beautiful. There's one species that is very well known in Colombia, Rhyncholacis clavijera. it changes colors. So the river that it is present is called the five-color river. And it's a major tourist attraction. JENNIFER: Yeah I�ve seen images of that. It is sort of otherworldly. I mean, it's absolutely beautiful. And it's the plants themselves that are giving the river those colors. ANA: It is the plants. Yes, it is a plants and they change color depending on the amount of sun that they're getting. But then in the dry season, when the water level drops, when tourists are no longer there because the river doesn't look that nice; when botanists are there, like me, the plant starts to dry up and we don't see the leaves that much. But instead they produce flowers that always project above the water surface. Those flowers don't have, for the most part, perianth. So sepals and petals are very reduced or absent. And it is the stamens that give the color to the flowers. And so it is a very aquatic plant with very non-aquatic flowers. JENNIFER: Hmm. Wow. That's fascinating. Where do you start if you're gonna plan your next trip? Sort of, how do you think about planning an expedition like this? ANA: Mhm. I think about a question. What do I want to know and what place can I go so I can answer the research question that I have? So right now I'm really interested in studying a project that I started. I contacted people at the Smithsonian Tropical Research Institute and so I'm studying a collaborative project with them. So that's the first part, establishing a network of collaborators that can support logistics of fieldwork. And then, because I've had experience before running expeditions, I usually check out the travel warnings by the U. S. Department of State. So that we can ensure that we're going to places that we're going to be safe at and then I contact local authorities as well. I always contact a local person, like a field guide, because people who are local to the places are the people that know better social norms, but they also know the plants better, which is also a really humbling thing that happens to us botanists. Is we can be as trained as we want, we can know taxonomy, but really, living in a place gives you this understanding of plant diversity that we need to be respectful of. JENNIFER: I think most botanists don't do some of the things that you've talked about, riding horses, and going into river rapids. It's very extreme. You've talked about how for a long time in history, botany was considered a sort of a soft science for women, something that was accessible to women because of the nature of it. What you do, I think, is in pretty stark contrast to that. So, can you talk a little bit about that dynamic? ANA: Yes, in 19th century America, it was said that botany was for the ladies because botany again, this misconception of being a soft science. And so, women like smelling good, I guess, and staring at plants and walking and skipping down the like prairie. Right? Um, and then shortly after, when botanists engage in these explorations to explore the plant world, women were actually deterred from going into the field and they were forbidden to going into the field. Because field work necessitated the strength of men, um, to carry pole pruners like we do, to engage in extreme activities like we do. And so, yeah, I'm really happy to bring the message that botany is extreme, and it is women that are doing this extreme botany. But I also stand on the shoulders of women that have done this in the past. I don't know if you're familiar with the book, Braving the Wild River. That came out a couple of years ago. This is the story of the first women that traversed and rafted the Colorado River. And they were botanists. And they collected there and navigated the river because they wanted to collect cacti. And so extreme botanists, extreme female botanists, have existed for some time. This was in 1930. JENNIFER: Braving the Wild River. ANA: Yes, Elzada Clover was the name of this female botanist. JENNIFER: Yeah, that's great, you know, there's so many interesting stories about that transition in the field. Elizabeth Britton, as you know, was one of the co-founders of NYBG and she was a bryologist and among other things she started something at the time that was known as the Wildflower Preservation Society. And at that moment at the sort of turn of the century people were using wildflowers in hats. And so she began this organization which became a national organization to stop the practice of wildflower poaching. And there are these amazing letters, where a group of, male scientists at one point, the organization got significant enough that they felt that it needed to be basically taken over and they wrote to her and said as much. I mean, they basically said, you know, this has become serious. And now the men are going to take it over, you know, and we've got letters where in the marginalia she's writing, this is so rude, you know, it's like; but that transition from something that starts as being understood as a female pursuit and then becomes understood as a male pursuit and now reasserting today's scientists like you, women reasserting their role in it, which is of course never really, left. It's not like women ever left the scene, but it's a very interesting part of history. After the break, we'll dive beneath the rapids to understand more about how aquatic plants thrive. Plus, we'll find out how these river plants can help us understand more about how the earth was formed. We'll be right back. BREAK Welcome back to Plant People. I'm Jennifer Bernstein and I'm speaking with Ana Maria Bedoya, an "extreme botanist" and Assistant Curator at NYBG's Center for Biodiversity and Evolution. During our conversation, I asked Ana why it's important to study the kinds of aquatic plants that she works with. ANA: Aquatic plants have very important ecological roles. They're the primary producers in aquatic ecosystems. They're the place of egg-laying for fish. They're food for cattle. They're food for fish as well. And so they're extremely important for the integrity and the health of aquatic ecosystems. In 2021 there was a study by WWF called Rivers of Food, saying that one third of the global food production depends on the world's rivers. Any research that we can do to understand better how these plants have adapted to live in these conditions, how they have evolved, how long they have been in here, it's very important. In my case, I think it is so interesting to learn about botanical oddities. There's no other group of plants that live like this in the neotropics. How do you live like this? Why do they live like this? That was my main drive. But then later on, I realized that my work could have implications for conservation. Because I think I mentioned before a little bit about the life cycle of the plants. And so in the dry season, the rivers dry up and so they produce flowers; then they produce fruits, then the fruit opens up and releases seeds that are kind of dust-like particles. They're very small and they attach to the rocks right away. And so these aspects of the natural history of these plants are suggestive of a very limited dispersal ability. What I came to do with my work is to try and use genomic data to test these hypotheses that we had with natural history observations that they have a limited dispersal ability. And what I found is that populations in different river systems are genetically distinct. Meaning that any threats to a river because of dam building, for example, because of legal mining, could threaten a whole population that is unique, that has a genetic constitution that you're never gonna get back. JENNIFER: I have some very basic questions about aquatic plants that I think that the audience might have as well. How do they breathe? When they're submerged? ANA: Good question. So, here's this cool story. And it�s that aquatic plants are all terrestrial plants. So in the evolutionary history of land plants, some groups of plants venture back into the water, recolonized aquatic ecosystem. So all aquatic plants are actually land plants. And so to get back into the water, they had to get into again, the stressful condition of how do I breathe underwater? And so they have different mechanisms. One of those mechanisms is to have their leaves above the water surface. And so you have these floating leaves, for example, the water lilies. JENNIFER: Hmm, mm hmm. ANA: But then some other ones have tissue called aerenchyma, and it's tissue that is highly modified, so it looks like a sponge. And so some tissue dies and creates these air chambers that preserve water inside, but also, improve the diffusion of gases in the body of the plants. JENNIFER: Hmm. So they develop different mechanisms, but they have to breathe. ANA: Yes. JENNIFER: They're not unique in that way. Okay, good. And you've talked a little bit about how some of them reproduce through sending out spores. Are there other mechanisms that they're using to reproduce? ANA: So the plants that I work with are all flowering plants, so they all use flowers for reproduction, but there's different modes of reproduction of aquatic plants. There's super, super, super interesting, actually, because there's plants that reproduce under the water; they have female and male flowers that are separate and that are in different nodes of the plant; and then the male flower would send the pollen tube within the tissue of the plant and then reach the female flower and then the sperm would be releasing the egg. That's a very extreme, very aquatic way of reproducing by water, but there's some other plants that release their flowers just above the water surface like Podostemaceae do. JENNIFER: I know that mosses and lichens have evolved to attach themselves to specific rocks and types of rocks. Is that also true for these aquatic plants? ANA: That's such a nice question because we recently got a gift from Tom Philbrick. He was the expert taxonomist of Podostemaceae and he passed two years ago, and he knew about the relevance of the botanical garden and how important it was for him to actually pass his legacy on to. The future generations. I met him personally, learned from him about these plants. And so he gave us these rock collection. We have over 200 rocks with the plants on them that are coming from different places in the neotropics. And so when I got here to NYBG and saw that treasure, I invited geologists to come check out the collection. So we have geologists coming to check out a botanical collection so that they can tell us about the composition of these rocks, what minerals they have, what type of formations were those, and that's a project that is right now going on. I call it Podostemaceae Rocks! JENNIFER: So maybe we'll learn a little bit about the relationship between these rocks and the aquatic plants that are living on them. That's really interesting. So, you've talked a little bit about natural history, and can you talk maybe a little further about how understanding these plants helps us understand the history of the planet, its formation, the formation of these different ecosystems that you're operating in? ANA: Yeah. So one thing I'm really interested in science is in the question of how botanical research can inform geological research. There's this strong link between geology and biology. Organisms evolved in a changing world. As the landscape changes, the organisms change as the landscape is changing as organisms are changing. So there's this strong link. And so I'm very interested in how can we use information from genomic data of plants to actually inform geological models? And in my case, learn about the history of connections of rivers in the past. The plants that I work with, the orchids of the waterfalls� JENNIFER: River weeds. ANA: �the river weeds, yeah. They are bounded by the rivers. They cannot disperse outside of the rivers, and through my research, I've shown that they have strong population structure, meaning populations in different rivers are distinct from each other. There's no exchange of genes. There's no transportation of pollen, of seeds, of vegetative fragments across different rivers. And so that means that we, in theory, can use mother analytical tools to then trace back the time when these populations that are in different rivers split from each other and use that as a proxy for when rivers split from each other in the past. JENNIFER: So you can use these different populations to understand the timeline along which the rivers split. ANA: Isn't that crazy? JENNIFER: That is amazing. ANA: So when, so when we're in the field and I'm collecting, I collect voucher specimens, so sheets that we press, but I also collect silica dried samples. And so, leaves that I dry in silica and then DNA is preserved better that way. And then I extract DNA from that and sequence whole genomes. It's really exciting to think that when you're in the field, getting your feet wet, collecting this material, that material holds the secret to changes of the rivers in the past. JENNIFER: That's amazing. So what kinds of threats are there to aquatic plants and what are the consequences for us when some of these species become endangered? ANA: So different plants have different tolerances and requirements. They're plants that are quite hardy and actually indicators of something going wrong. There's plants that are very delicate and they're indicators of good water quality. And Podostemaceae may be one of those. I've been to sites where plants have been collected in the past and all of the sudden, when I go, they're not collected. And then I learned that there was a mining project there. With particles that are suspended, suspended particles drive these populations to extinction. Maybe not species, but yes, populations to extinction. And if species have restricted ranges, then a whole species can be wiped out because of these circumstances. They're very delicate to the chemistry of the water as well, even though we don't know that well the chemistry of the water that they live in. They always are only in whitewater rivers. They're never in blackwater rivers, for example. At least the ones that I study. Some other species may be in blackwater rivers, too. JENNIFER: Well, we're very happy to have you. You're part of a community of new scientists that have joined NYBG and are doing really interesting work. So we're thrilled that you're here. What's next for you? ANA: I have so many projects going on. Like I mentioned before, I'm really interested in using botanical data to inform geological processes. So I started a project in Panama and this is an interdisciplinary project. So there's geologists working on it, paleontologists. And so we're very excited. We just submitted a proposal; knock on wood that it gets funded, but basically we are looking into using botanical data, geological data, and paleontological data to reconstruct the history of river connections across time and space in certain places of the world. I have other projects that deal with microfossils. This is the thing. I love plants, but these plants take me to crazy places that take me to learning about rocks. Now I'm learning about microfossils because aquatic plants, they are very flexible. They lack new lignin for the most part. Cause if you have� JENNIFER: Lignin like in wood. Like it�s a structure. ANA: � like in wood; imagine you have wood and you live in these rapids, you're going to break. So you need to be flexible, and so they lack wood, and because they don't have this lignified tissue, they don't preserve well in the fossil record. So we don't have any macro fossils of these plants, but it turns out they accumulate a lot of silica. So much as when you see the herbarium vouchers they are covered in these very nice crystals. That's all silica. And there's these, silica bodies called phytoliths, and phytoliths are microfossils, that are the silica bodies that are shaped in a certain shape depending on how the silica is deposited in the intracellular and extracellular spaces. And they are deposited in the fossil record. So you can find it in fossil soils. And so it turns out that the microfossils of Podostemaceae are diagnostic. So what this means is that we can now look at the fossil record of Podostemaceae and kind of have evidence for the presence of rivers in the past. So my work on that has been describing the morphology, seeing and learning about how is it that these microfossils are deposited. And for that, I've been working with Caroline Stromberg, who is a paleontologist that specializes in microfossils. JENNIFER: Okay, so let me get this right, because I want to make sure that I understand it. We've got small aquatic plants or pieces of aquatic plants that have become attached to silica that are then in soil that is fossilized? ANA: Yes, so the plant has cells and the cells accumulate silica. So there's silica inside and outside of the cells. And so when the plant decays and all the organic matter decomposes, these microfossils remain. And they remain deposited in the sediments. And then, through time, they will be buried in the sediment. And across millions of years, if you're able to date when that sediment was deposited, then you know that there was a river at that time in the past. JENNIFER: That's amazing. That's very, very cool. I have to ask, what made you choose to come here to NYBG? ANA: That's an easy question to answer. There's a very strong link between NYBG and botany in Colombia. NYBG is one of the meccas for botany in Colombia to the point that a lot of the botanists that have trained people in Colombia have received their PhD from NYBG. And so growing up and training as a scientist, I had that as a reference of a place that I wanted to visit. I never dreamt of working there. And then I guess pursuing my passion for plants, I'm so lucky that it took me to realize my dreams. My research is about exploring the world. That's what NYBG has done for years; and advancing our knowledge of the world around us through plant research. And so I am just a very lucky person. JENNIFER: Well, we're lucky to have you, so thank you for being here. To learn more about extreme botany, check out the links in our show notes. We also have a link there about NYBG�s graduate studies program that Ana just mentioned. In our next episode, my guest is Amy Stewart, bestselling author of books like the Drunken Botanist and Wicked Plants. We�ll discuss her latest release The Tree Collectors, and her conversations with the passionate plant people that inspired the book. Thanks for listening. If you're a plant person and want to give us a boost, please rate us on whatever podcast app you use, like iHeart, Spotify, or Apple Podcasts. And don't forget to follow NYBG on social media. As a special offer for first time members, use the code PLANTPOD on nybg.org for $10 off our most popular levels of membership. Plant People is a co-production of NYBG and PRX Productions. From PRX, Plant People is produced by Jessica Miller, Courtney Fleurantin, Genevieve Sponsler, Adriana Rozas Rivera, and Pedro Rafael Rosado. The executive producer of PRX Productions is Jocelyn Gonzalez. From NYBG, Plant People is produced by Charlie Nork, Cosette Patterson, Matt Newman, Kait Tyler, and Michael Crowley. Music from APM Music. Sound effects from Epidemic Sound. Views expressed by guests are their own and not necessarily representative of NYBG. 1