We Are Nature

Herbaria for Humanity

• Carnegie Museum of Natural History • Season 2 • Episode 6

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How do humans support some plants and endanger others? What do herbaria teach about climate change? How can people and plants collaborate towards livable futures? Featuring Mason Heberling, Curator of Botany at Carnegie Museum of Natural History, and Bonnie Isaac, Collection Manager of Botany at Carnegie Museum of Natural History.

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Michael Pisano:

You're listening to the Anthropocene Archives, a presentation of We Are Nature. In this special series of stories, we're delving deep into Carnegie Museum of Natural History's 22 million collection items, raiding cabinets and cases, sifting through objects and organisms in search of stories of stewardship, solutions, and scientific wonder. On today's episode, an endangered narrowly local, a thriving garden fugitive, and gratitude for our green world. We're hanging in the herbarium with two unbeliefable botanists. So turn it to the volume. This'll be an episode to remember. Welcome to We Are Nature, a show about natural history and livable futures presented by Carnegie Museum of Natural History. I'm your host, photosynthesis MVR Michael Pizzano, and today I'm joined by two botany experts. Friends will you please introduce yourselves?

Bonnie Isaac:

Hi, my name is Bonnie Isaac. I am the collection manager here at the Carnegie Museum of Natural History. I've been here since 1989, and my area of interest is endangered and rare plants of Pennsylvania.

Mason Heberling:

Wonderful. And? My name is Mason Heberling. I'm the Associate Curator of Botany here at Carnegie Museum of Natural History. My research is pretty broad. I'm interested in kind of global change, environmental change, impacts on plants, in particular invasive plants, and also impacts of climate change.

Michael Pisano:

Perfect. Thank you both so much for joining us and for bringing us behind the scenes of the botany collection here. And I was wondering if just to kick us off, you could tell us a little bit about the museum's plant collections.

Bonnie Isaac:

Yeah, we have around 550,000 specimens from all over the world. They are all pressed and dried and glued down to archival quality paper with a label on it that says what it is, where it was collected, and who collected it.

Michael Pisano:

That's incredible. And can you tell me about the kind of time scale that this was collected over?

Bonnie Isaac:

Our earliest collections are from the late 1700s. Our most recent collections are from like yesterday.

Michael Pisano:

And it seems like there's um a pretty consistent methodology here. Can you describe kind of what we're looking at here in terms of this preparation in an herbarium?

Bonnie Isaac:

What we do is we will collect the specimen that we're interested in and we will put it in a plant press, which consists of newspaper and cardboards, and we will press them and then put them in front of a heater fan to dry them. If we dry them quick, they'll keep their color better and they'll retain their DNA. And so once we have them pressed and dried, then we will glue them or linen strap tape them onto archival quality paper so that we can store them in all these beautiful cabinets.

Michael Pisano:

Do you have a sense of how many of these types of specimens you've prepared?

Bonnie Isaac:

I do not. I personally have collected about 30,000 specimens.

Michael Pisano:

Wow, that's incredible. And so you said 550,000 here in the museum. That is a pretty incredible amount of plants, obviously, but I'm sure it kind of pales in comparison to the species of plants, the biodiversity out there in the world. Can one of you tell me kind of about what we think the plant biodiversity out there is globally?

Mason Heberling:

So it depends who you ask, but probably the number of taxa or number of different species of plants in the world is somewhere on the order of 350,000, give or take. Depends again who you ask and how you splice up what's a species and what's not a species, and that's constantly changing. New species are always being described. What we know is now what you know what was two species may become one, and vice versa. So it's an ever-changing thing, and that's why the herbarium's important for that.

Michael Pisano:

Yeah, speak a little bit more about that. Like I know that it's almost an impossibly infinite answer, maybe, but maybe there's something you can do with it. Like, I'm curious about the types of research that can be done from this sort of specimen.

Mason Heberling:

So there are many uses of herbarium specimens, some of which we are only recently kind of realizing or appreciating. So when the kind of institution of herberia, which is the plural of herbarium, kind of began, you know, probably, you know, in the 1600s, give or take, really was about plant exploration, right? And also the novelty of plants growing far away. This is from a European perspective. Right. A couple decades in, it really did become a very strongly scientific enterprise, and that is naming, describing, cataloging plant diversity across the world. And so that kind of core use of specimens remains. So kind of taxonomy, naming plants, where plants grow, where plants can be found, where plants were found, which I'm guessing we might talk about here later. And so that's kind of the core is taxonomy and systematics. And that's kind of what you think of usually when you think of a specimen or a natural history museum in general. But there's a lot more than that that's that has been happening. So though that's remained the core, a lot of other uses, so in particular, kind of ecology, so using these specimens in some ways, um, it kind of acts they're kind of accidental in a way. So we can look at like flowering times as one instance, you know, as Bonnie said, each plant has the label of where it was collected, when it was collected, with physical material. So there's kind of a lot that you can do with that looking at in particular looking at change, but not only looking at change. So in the case of phonology, I mean, by phonology, we mean kind of the recurring biological cycles in nature. So, you know, bird migration, for instance, or in the case of plants, plant flowering times, or leafout times, or leaf drop times. So from these specimens, we have a record of if the plant was flowering at a given time and in a given location. And so, with you know, a couple dozen, hundred, thousand specimens over the last couple decades, hundreds of years, we can look at long-term changes in flowering time. So, one kind of gut hypothesis is that as springs get warmer, plants respond by leafing out and flowering earlier and earlier. So we can use your variant record to look at that kind of at a species level or even at a regional level. And then the neat thing about that too is it also kind of might seem simple, but it's actually quite complicated. Different plants respond to different phenological cues. Not all plants respond the same. How does their pollinators respond, for instance, or how do their competitors respond? So it's kind of this um it's it's much more complicated than just earlier springs equals earlier flowering times. But that is just one example of many, which I could continue um blathering on with other examples. That's great.

Michael Pisano:

We'll blather more, I think, throughout the hour. Um I'd love to move into the kind of collection items that we've brought. And Bonnie, maybe we could start with what you've got here.

Mackenzie Kimmel:

Prior to being flattened and affixed to a piece of paper, collection item one grew almost a foot tall from sandy soil. Its signature narrow leaves are opposite, meaning they grow in pairs originating at the same level on the stem on opposite sides. If you encountered this item between September and October, you might be mesmerized by a unique blue flower. The blooms and stamens curl up and over the petals in an elegant swoop. The anthers are suspended in space like a pollen-laden lure. What is collection item one?

Bonnie Isaac:

This is trichostoma cetaceum, the narrow-leaved blue curl. This plant has a blue flower that has a nice little curl on the end, and hence its common name, blue curls. It grows on shale barrens, so very open, hot, dry areas. We have three species of trichostoma here in Pennsylvania. Two of them are fairly common, and this one is endangered on the on the state's endangered list. So I was doing some uh survey work for Kate's Mountain Clover, which I had a grant to do a few years ago, and so we were at a site where we had there was a historic record for Kate's mountain clover. And while when I'm out doing rare plant surveys, I like to look at what are the associated species and what else is there. And I collect voucher specimens. So voucher specimens, I think, are critical for any kind of plant work you're doing because it documents what you have, and then we can actually physically look at it again later. And in this case, it became super critical. We'd found the Cates Mountain Clover and we were documenting the surrounding vegetation in addition to this plant, which I thought was the common blue curl, and so I collected a voucher, and then I also collected a vine that I had no idea what it was, and I brought it back, and we are now putting QR codes on our labels, which link to iNaturalist records. And that plays in on this one because I identified it on iNaturalist as one of the common blue curls, and the the expert for trichostema is uh active on iNaturalist, and he looked at my photographs and he said, I think you've got the narrow-leaved blue curl. And so I went back and looked at the specimen, and absolutely he was right. And one of the reasons I didn't originally even consider it to be the rare one is because the only other sites for this in Pennsylvania are in the Far East. And I was in uh Fulton County, which is in the South Central. So it is known, I know now that it's known just across the line in Maryland, but just looking at Pennsylvania, it wasn't anywhere near there. So I didn't even cross my mind that it could be the rare one. And then when I came back and brought the vine that we found, we discovered that it was a plant, a galactea, that hadn't been seen in Pennsylvania for like a hundred years. Incredible. And this, the previous known voucher specimen for it, was like 80 or 90 years. There was a site record for it 20 or 30 years ago, but there's no voucher specimen, so I can't verify if that's really what it was or not. Gotcha.

Michael Pisano:

So you're setting up someone, hopefully, in the future with these voucher specimens to be able to go back.

Bonnie Isaac:

Absolutely. I mean, that's what I like to do, is I'm looking at historic voucher records and then I'm trying to go back to those same sites and see if the rare and endangered plants are still there and if the habitat is still intact. And that's an issue with a lot of our rare plants is that there's been habitat destruction or habitats being taken over by non-native species.

Michael Pisano:

And so with this specific blue curl, can you tell me what kind of factors lead into it being endangered in this state?

Bonnie Isaac:

Part of it is that it is it occurs on Appalachian shale barons, which is an in uh fairly rare habitat, which the clover that I was looking for, the Cates Mountain clover, is also an endangered species in Pennsylvania because it is a limited habitat in the state.

Michael Pisano:

Aaron Powell What makes this kind of barons habitat less common than maybe it once was?

Bonnie Isaac:

People building on them, you know, bulldozers.

Michael Pisano:

Sure, development.

Bonnie Isaac:

Development, yeah.

Michael Pisano:

Um and can you kind of speak to, I guess, other you you've already mentioned a few, but other reasons um that plants become endangered? I mean, I just I feel like they're so left out of conservation narratives. Um I'd be curious to kind of fill that in a little bit.

Bonnie Isaac:

Yeah, the the main reasons why plants become endangered is one, it could have just been a rare thing to begin with. Sure. You know, but two, there is the development issue, and there, you know, which is uh habitat destruction. You know, so a lot of places where the rare plants grow are things, you know, places where, like, you know, if it's a limestone cliff and we need limestone to make cement or whatever, you know, so it could be mining. It and a lot of the barons have special minerals in them, so they do get mined. And so there's can there's development, there's invasion, there's just people not knowing and mowing it for their lawn, which was one of the sites. The the site record for this, we went back to visit, and the guy had been mowing everything. So that's so tough.

Michael Pisano:

Yeah, it's gotta be kind of heartbreaking.

Bonnie Isaac:

Yeah, but you know, it's private property and in in most states, yeah, the landowner owns the plant. Got it. And they can do what they want.

Michael Pisano:

Sure. And you know, you're coming up against a pretty entrenched culture of how people manage land.

Bonnie Isaac:

Yeah. And most people just are unaware. They don't really know that there is even a possibility that there's a rare plant there. Because you normally, if you find a landowner and you talk to them about the rare plant, you tell them it's there, then they're like, oh, that's cool. You know, and then they'll maybe protect it. But there are also landowners that are like, I don't want that here because maybe the government will tell me what to do with my land. And so they remove them on purpose.

Michael Pisano:

Interesting. Wow. I would not have thought that happened. Um, but of course, I understand. Um, again, I guess I feel like, you know, these I don't hear many stories about rare plants, endangered plants, right? There's obviously like a charismatic megafauna uh monopoly on a lot of conservation narratives, which is not to say that, you know, those are bad narratives or that they don't protect the habitats that also contain rare plants or rare insects or less charismatic things. But I am kind of curious about what you would each well, maybe we'll start personally. Like, what's charismatic about this plant to you? And what's charismatic about this plant to you? Maybe we'll start with you, Mason.

Mason Heberling:

Jeez.

Michael Pisano:

Yeah.

Mason Heberling:

Uh I mean, I don't know because I must say I don't know this species. Um hearing Bonnie's story is beautiful and I have a respect for it. I think every species kind of has a story to tell. And even at the local level, every kind of local environment, the the different organisms in it really do have a story to tell. And the closer you kind of look and pay attention, I think that there's a certain level of inspiration there. Um that's kind of my general um philosophy on it. I feel like even the most boring of plants that you might think is boring and unexciting upon closer inspection has something really interesting about it. It could be, you know, how it's pollinated or how it grows or its life cycle or the color of its flowers or the diversity of the different leaf shapes and sizes within the same species. I mean, the list goes on and on, so I feel like there's just like a ton to observe. And dare I say plants are the landscape, so there's a lot of um, there's a lot to work from. And without without plants, um, our landscape is um non-existent, really.

Bonnie Isaac:

So without plants, life on earth would be pretty much non-existent. You know, we we we very much rely on plants. They're the basis of our food chain. Um, we're all wearing plant-based clothing. We breathe oxygen, which is thanks to plants. Our houses are made out of plant material.

Mason Heberling:

I mean, we pretty much other organisms rely on plants too. Yeah. Right. Pretty fabulous. So yeah.

Bonnie Isaac:

Yeah, it's I mean, it's the base.

unknown:

Yeah.

Michael Pisano:

Uh I'll take I'll take us back to that question that I posed to Mason. I'm curious why you personally, you know, outside of those obvious I couldn't be alive and this planet wouldn't be here enough.

Mason Heberling:

Is that not a good enough for you?

Bonnie Isaac:

No, I need more. You want more. Okay.

Michael Pisano:

Like, why should people slow down and and you know take the time to see that story that Mason's talking about? Why do you do it?

Bonnie Isaac:

If you really get close and look at some of the plants, I mean, when you're just walking by, it might look like a green blur. But if you really stop and get close, you can see the intricate details. I mean, you can see that on this specimen, the flowers are not very big. What are they like? Maybe a you know, a quarter inch. But when they're, you know, in full bloom, they have this absolutely gorgeous spiral curl flower with the anthers and the you know, stigma sticking out. And there's usually a story to that too, that the way the flower forms is how the insect can come in and get pollinated and carry the pollen around. So it's just it's just an intricate story of how things interact.

Michael Pisano:

I bet it's super satisfying too, right? You've you make that loop, and I think people make those uh outside of nature very often in their lives where you gain some expertise, then you see the thing, and you identify and you say, Oh, I know that. And yeah, that's a nice, that's a special feeling. In terms of kind of practical steps, I wonder how we might go about conserving and revitalizing populations of this and other endangered plants.

Bonnie Isaac:

It's protecting the habitats and you know, keeping the non-native things that may be crowding them out, you know, so it's going to be active management. I think it would be really nice if we could get some kind of policy where native plants are protected, because right now, like I mentioned, the plants are owned by the landowner, so it's totally on the landowner to maintain what they have or to protect it. The state can only protect what's on state properties. Right. You know, so which is pretty limited. Which is pretty limited.

Mason Heberling:

Yeah. But that does place a bigger value than on public lands, I suppose, given that context. Yeah. Which would not be so bad. There's something else I wanted to say, actually. And this was um just to give Bonnie a shout out in particular, because she's so humble. But I would say a big part of this too is just inventorying, no knowing what's out there. So I mean, if Bonnie didn't collect this specimen and have this story, we wouldn't know potentially that that population was there. I like to think that's part of our contributions, our professional contributions to the story is really this baseline of what's there, when, and why. And I think that knowledge is of course important to then inform these some of these higher-level complicated decisions. But if we don't know that it's there, then kind of flying blind.

Michael Pisano:

Right. And that has been proven in land management and wildlife management to not be the greatest way to fly. Um, same in a plane. I would also say that that data, the baselines, are what policymakers will end up looking at. They're not here in the herbarium looking at each specimen or in the woods thinking about those plants. They're reading that aggregate. And so, yeah, I really appreciate you bringing that up. And I think if there's anything else you want to say, because I know the collections are kind of you've been here working with them for a long time. Is there any other something you want to say about uh you know how these collections contribute to conservation efforts for native plants and maybe more broadly to bolster environmental health?

Bonnie Isaac:

As Mason mentioned, you know, every specimen has a story to tell. But by looking at where the plants occurred and when they occurred there, we can actually track, you know, the distributions of the rare plants and the common plants and what common plants might be getting rarer, or what rare plants could actually be getting more common based on, you know, maybe environmental change or habitat manipulation. Because there are some plants that we thought were rare, but they really like disturbance, and there's a lot of disturbance going on now, so some of those are expanding. So it's not necessarily that because it was endangered, it's always going to be endangered, because it just with habitat manipulation, things are changing. The flora is dynamic, and the herbarium is basically our way of documenting that. We can document and see how the flora is changing over time and over distance and throughout the world, really.

Michael Pisano:

Excellent. And yeah, make informed decisions about what to do to be good neighbors to all of it. Excellent. I do want to move on to this other specimen that we have here.

Mackenzie Kimmel:

Collection item two is a small squished snipping of a plant that easily grows past 10 feet tall. Often mistaken for bamboo. Its edible shoots are segmented, hollow, and broad-like. Its heart-shaped leaves are arranged alternately, meaning only one grows from each node on the stem, and they alternate between opposite sides. This collection item was likely taken from a dense, thicket-like stand, which this species is known to form, especially alongside bodies of water. This herbarium sample includes the plant's bright white clusters of delicate bushy flowers, which are reminiscent of a pointalistic painting in their flattened form. Can you identify collection item two?

Mason Heberling:

So here is kind of a slightly more tinged paper than Bonnie's, slightly older specimen collected in 1920. Some kind of medium-sized leaves smashed to the on the sheet with some seeds, some fruits there, and a stem, and it's a pretty full sheet, otherwise. Collected September 18th, 1920. This is a knotweed specimen collected by Otto Jennings. And on the handwritten label it says Established and Forming Thickets along Lowry's Run above Emsworth, Allegheny County.

unknown:

Wow.

Bonnie Isaac:

Just a curious note that it just you just said September 18th, 1920. Is that today? No, it was yesterday. This one was collected September 18th, 2020. They were exactly a hundred years apart.

Mason Heberling:

We actually didn't.

Bonnie Isaac:

It was totally accidental. They were a hundred years apart.

Mason Heberling:

We didn't plan that.

Bonnie Isaac:

It's kind of um 100 years ago yesterday.

Michael Pisano:

Type of wonderful coincidence that could only happen in this room. That's very cool.

Bonnie Isaac:

Exactly a hundred years apart.

Mason Heberling:

So that's fun. Um but yeah, so kind of this is kind of the opposite side of the coin of um Bonnie's example of a species of conservation concern. This is kind of the opposite. It's a non-native species also of conservation concern, but because of the impact that this species has on the native flora.

Michael Pisano:

And before we get into talking about its story as an introduced species, I do want, I'd love to hear about it as a species. Because I think most people hear knotweed, they have a feeling, yeah, they have a vision of it, but uh, you know, living where we live here in the United States, we don't know about it in its native range. Yeah. Can you just tell me about this as a plant?

Mason Heberling:

Yeah, it is a species that has a long history, I guess I would say, a long human history. But the the plant kind of species complex can be found in East Asia. So China, Korea, Japan, and the Russian Far East. So also a temperate forest ecosystem like ours, but on the other side of the world. A lot of people don't in the native range don't necessarily think too much about it, to be honest, which is kind of an interesting thing considering its commonness here and and um not so much in its native range. The complexities, the social human complexities of non-nativeness. But if you didn't know of non-native, I mean you might actually quite you you would have a different, perhaps a different opinion of the of the plant just seeing it, because it does form very dense thickets, especially along like riparian areas, along the rivers of Pittsburgh, for instance. There was a vine that swallowed the south or whatever. I would say this might be a um an herbaceous shrubby thing that swallowed Pittsburgh. I don't know for sure. Um, but it's quite quite fascinating, and it's got a really interesting um taxonomy, biology to it. Um, so in Pittsburgh, we kind of are this um, dare I say, this haven for this incredible morphological and perhaps genetic diversity of this species complex. So we have um the two parent species, um, giant knotweed, um, Japanese knotweed, what we call Japanese knotweed. Um, and then they also hybridize, which is Bohemian knotweed. And in fact, this is has been identified as Bohemian knotweed, the example I have um here in front of us. So there's kind of like this huge range of morphological variation, leaf size. So giant giant knotweed has giant leaves. Japanese more kind of circular, come to a tip, and then the then they hybridize and there's kind of variation. Even within stands, there's considerable variation. But it's really quite impressive how how the plant grows and spreads and how it seems to do pretty well in a lot of different contexts. I mean, sometimes you look at a stand and you might think, oh, what could have been here? But in all reality, I don't know. Some of the locations are what could have been here? I don't know. Not without significant restoration because the site has been kind of muddied up in a variety of ways. It's kind of impressive that the plant is doing so well.

Michael Pisano:

And is uh the presence of a plant there at maybe like a fringe of where a plant is comfortable growing in our region, is that remediating that space at all for another plant? Or no, no, that's not really the case.

Mason Heberling:

No, not really. I don't think I'd be comfortable saying that. I don't really think so. Um, so at one of my field sites, there there are like an actually an impressive amount of wildflowers, forest wildflowers growing under some knotweed. And we're studying that, but we really think it's kind of an ephemeral, a short-term thing, and probably um things in the in the understory of this shrub probably would be much happier without um the competition from the knotweed, and probably the long-term, long-term outcome probably won't be great for those plants growing under there, but it is kind of an interesting, it's an interesting dynamic.

Michael Pisano:

Culturally, this word invasive has some baggage to it. I've heard some scientists really trying to get away from the term itself. I'd just love to hear your thoughts on you know the dynamics there, and for maybe people who haven't heard that discourse. What how is it shifting? How is talking about invasives more nuanced than it was 10 years ago?

Mason Heberling:

Yeah, for sure. I don't know. It's really complicated, I guess I would say. And it's something we're like really exploring here. We have a um an ongoing active ongoing project about invasive species communication. And that originally started when we redid the um some of the labels in the hall of botany here at the museum with these fantastic dioramas of different vegetation biomes of North America. They're really like, really beautifully done. As we were writing, updating the labels as an invasion biologist, somebody who studies introduced plants myself. I figured, oh, we should write something in the labels to kind of at least bring up this topic of non-native introduced plants. Because actually, what was in the label before was something along the lines of herbs escaping a garden might become a fragrant addition to the landscape, was in there. And I so I was like, ah, that's an that's an interesting take on it. But then, so then anyway, we we wrote some very short text that actually was on Japanese knotweed. You know, something along the lines of, you know, Japanese knotweed is is introduced, is now quite common along Pittsburgh's waterways, or something along those lines. And then some others at the museum, you know, as we're like reading the labels. This also was around the time of um a lot of anti-immigration sentiments in the US. So it was kind of like, ooh, I mean, it wasn't our intent, but we also didn't want a museum visitor to perhaps misread that or take it a step further, that we don't want Japanese people here, for instance, or very xenophobic or something. So that kind of brought it to my attention, I guess. I had very much had my narrow lens on of seeing um introduced plant, you know, all about natives and all against non-natives in terms of this kind of binary and and thinking, you know, even if this plants aren't, we don't know that they're doing bad right now, they they will eventually kind of like kind of thing. And so now as I think about it more and more, I realize that the language that we use around invasives, which I'm I'm okay with the term invasive, I will say, but kind of how we talk about it, and maybe it's important to put it in context and to also kind of frame it in a way that is not that is inclusive and not um xenophobic. And in fact, one of the ways is what you did is kind of talking about the plant as a, you know, an invasive, you know, as a plant and not vilifying the plant per se, but instead actually taking a step back and not being like Japanese knotweed, what a horrible plant that's taking over, but instead be like, you know, humans, what have we done to bring this plant here and to make like, you know, the plant is not to blame. So this kind of villainization of the plant, I think, is is one way around it. And in fact, realizing that it's not the fault of the anyone from Asia, even, right? It's um it's the fault of trans of transport and this species. We could probably talk for an hour easily about the the um the introduction history of this plant.

Michael Pisano:

The U.S. Department of Agriculture's formal definition of an invasive species is, quote, an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health, end quote. I wonder, by the USDA's formal definition, what else in the American landscape becomes invasive when viewed through the lens of the current ecological crisis? For example, climate science is clear that industrial-scale monocultures of non-native soy, corn, wheat, cattle, pigs, and lawn-their crises all cause environmental harm. The concept of invasiveness is contextual, and it merits an update if we actually want to deal with the material problems posed by some neobiota. The current approach of check your boots or kill it with fire is frankly insufficient for some of the really vigorous invasive species, like knotweed, the ones with a special talent to overwhelm, outcompete, and otherwise wreak havoc. Which brings us to colonialism. Invasive species. Both the large-scale human-driven global spread of organisms and the concept are legacies of colonialism. Take the post-1492 Colombian Exchange. Picture European ships bringing livestock and seeds to remake the new world in the image of the old. What else could our landscape look like? The word invader carries its own meaning, an implication of malicious intent to seize and consume and remake a foreign image. Exactly the colonizer's ethos that logged the American old growth, tried to eradicate the buffalo, and committed genocide against indigenous Americans to make way for European grasses and livestock and lifestyles. Colonialism is inextricable from the problems and concepts of invasive species, not to mention from natural history as a whole. And so solving the material problems with invasive species must include decolonizing our response. A decolonized relationship is one of coexistence, not control. It's collaboration between peoples, disciplines, and species towards mutual benefit. It's creating new practices together in service of collectively established goals, setting aside old ideas that no longer serve us, to make room for what might be born next. This is not to say that we should just believe the knotweed, the lanternflies, the trees of heaven, to do what they will unimpeded. Rather, it's to say that our response to the alien should be based in our curiosity, not fear, and in what we can create instead of what we must destroy. Importantly, this means gathering many voices at the table, especially indigenous voices, to find the right way forward. So please take all of this with a grain of salt. That's just my personal contribution to what needs to be a collaborative conversation. We must learn to care for the native plants that are stressed by the presence of alien competitors. We cannot completely shut out neobiota. Globalized trade isn't about to grind to a halt, so it will continue to shuffle species around. And as the climate shifts, species ranges are shifting with it, including the plant species that we rely on for food. We will need to accommodate these range shifts and find ways to welcome climate refugees. This work doesn't need to wait for permits, policy, or approvals, nor should we expect anyone else to handle it. Biodiversity needs investment from many hands, and there's no better time than now. In focusing on plants and their rich, small, interconnected world, our interconnected small hands have ability to make huge differences. By electing active participation, we can uncover our potential as a great constructive force for good. This is an old specimen. I would have thought that Notweed was more uh introduced by globalization in maybe the last 30, 40 years, but I am wrong. Tell me.

Mason Heberling:

Yeah, well in Pittsburgh, I mean this is so I guess I should have said too, this is the earliest specimen. We actually have a couple specimens from around this year, but it's the earliest specimen that we have for the Pittsburgh region. But in North America it was introduced much earlier, so like the 1860s. But its history is definitely very colonial and probably multiple points of introduction, but into the horticultural trade. So at a time when Europeans in particular were um interested in bringing new plants back, either for their beauty or for human use in other ways, in more practical ways. But yeah, this plant was brought to um actually to the Netherlands from Japan in the 1800s, kind of made it into the horticultural industry, was actually just sent to um Q in the UK, and then it was then introduced subsequently to the US from the UK. But then there also is some evidence that there's some direct introductions too from Japan directly to the US. So it's quite complicated, and there's a lot of different genetics. So it's said that you know Europe is largely one maternal clone and doesn't produce seed quite as much as in North America. Um so in some regards they hybridize post-introduction as well, perhaps in different ways than they would in their native range, too. But in terms of like invasives or non-natives in general, I just think Yeah, there's a lot to it. There's a lot of nuance about how we talk about it, and also kind of on one hand, you know, being inclusive and kind of you know being careful about how we talk about them, but on the other hand, also kind of communicating the the real environmental concern that non-natives do pose. And so by invasives versus non-natives, I could maybe give a little definition there as you know, non-natives is are organisms that are don't have an evolutionary origin in the in the region. Right. And then upon introduction, they may or may not be able to sustain without human, without human intervention in gardens, for instance, or farms. But sometimes they spread either on purpose or or accidentally and become naturalized. So these are species that a subset of these introduced species that can form self-sustaining populations, so they can grow in the wild and and reproduce seed or however they spread. And then a subset of those are these, is are this kind of invasive group, which is a much smaller subset. And it's the invasive group that is like of most concern because by definition, these are species that are actively spreading across the landscape and cause some sort of economic or ecological harm. So oftentimes we think of weeds as being, you know, a plant out of place, which may or may not have an economical, you know, it might be a pain in your garden, or it might be an economic problem in the farm field, which has huge implications. Or like this species, for instance, has certainly an economic cost, but definitely an ecological cost for the reasons that we said before, you know, crowding out natives or changing the landscape in a variety of ways. Yeah.

Michael Pisano:

Which has these ripple effects through the ecosystem, definitely. I'm glad you brought up the word weed, I think, while we were kind of on words, just for a second. The word weed is included in plant names. What do you what do you think?

Bonnie Isaac:

Well, the definition of weed is a plant that occurs where you don't want it.

Speaker 4:

Yeah.

unknown:

Okay.

Bonnie Isaac:

And so and bringing it up as as part of the common name is a whole nother issue because common names vary from different localities. Right. And a lot of times the common name for the plant has nothing to do with what the plant actually is. So I personally don't know that there are any weeds per se, because I like all plants, even if they're native, non-native, because they're interesting. You know, it's like, why is that here? How did it get here? You know, so there are a lot of plants in my yard that I wish were not there. Sure. But I'm still like, how did they get there? You know, and it it fascinates me, things like how garlic mustard and stiltgrass, how they spread so fast. I it just it's mind-blowing to me how fast they spread. And a lot of people consider those weeds, and if they're a plant that's where we don't want them, then by definition it is a weed. But having the word weed in the common name is that's uh kind of a colonial thing there too.

Mason Heberling:

Right, like milkweed, for instance. I think the whole um the I think there's been a changing narrative around like milkweed in particular with monarchs and things. Um so I think I think the the term weed is not quite, maybe not quite what it was, you know, several decades ago because maybe because of milkweed, I don't know, or this embrace of plants.

Michael Pisano:

Hopefully, yeah. I think I still encounter plenty of people who hear weed in a plant's name and say, oh, like why would I buy that? Coming back to knotweed. Yes. Uh I'm curious from both of you. You know, you hinted at this idea of like being curious about why something pops up in your yard. Um, what do you kind of take away from the predicament around knotweed and its presence here?

Bonnie Isaac:

That's kind of a loaded question. Um I I really pass. Sure.

Speaker 4:

Mason, you've got to meditate.

Mason Heberling:

Well, I'm fascinated by it, and I'm like shifting a lot of my research towards this species in particular. You know, it has a fascinating biology, a fascinating introduction history, um, and also it's it's an interesting predicament. And what do we do about the problem of even just this one species, for instance? I mean, it's a species that is kind of like hard to control. So that's what people ask. Again, I don't really know that that much about it. I'm not like a practitioner, um, but people will ask, you know, how do you control it? And it's like, well, kind of the latest recommendation is a herbicide spray at a particular, I mean, there's some science around it at a particular time. So late season herbicide spray, no cutting. They find if you cut it, the plant actually seems to do better because it's maybe not to better, but it's it's encourages its spread, which is not what you want. So there are there is like a careful management thereof. But it's hard when you look at like, I mean, acres and acres of knotweed, and it's kind of like, well, is the solution to spread? Like, what's our goal here? Is it eradication? Is it specific management? I mean, I think a lot of the communication, I think it's a great kind of poster species on the importance of understanding that us humans have a big impact on how plants spread and preventing new invasions, but also a more kind of curating, also like doing management in a very targeted way, though. Because I think I don't think the goal is to spray all of Pennsylvania with herbicides once a year continually. So there is, and you know, then of course that also brings up some people are very anti-spraying, some people are are you know for it. Like, I don't know, it brings up all of this these things. And in fact, this last summer, it was it was pretty, it was pretty fun and interesting. There's a a knotweed festival in southwestern Pennsylvania, and we had a table there. It was it was really kind of cool just to talk about the species and what it what it means to people. Like a lot of people also have no idea why the festival is called the Knotweed Festival, so that was kind of a fun thing to bring to it, be like, well, look, and this is when it was introduced in the region, and da-da-da-da, and that's what it is. And they're like, Oh, yeah, I know that, I've seen that. But also, you know, others bring up positive things about knotweed, like, ooh, it flowers at a time when my honeybees don't have as many flowers and we love knotweed honey. And so it adds this like extra layer of like, you know, am I supposed to uh, you know, like yeah, place that in some into some context and not um, yeah, I don't think we should be propagating knotweed for honey production. So yeah.

Bonnie Isaac:

I mean, it is taking over habitat of native plants and some that are endangered, you know. Yeah. So it's it's discouraging some of our native plants that we're trying to encourage.

Michael Pisano:

It's clearly here, though, and it's not simple for it to not be here. It's ingrained in our culture, I'm hearing. That those aren't the reasons to let other things fall away. So this is clearly tricky. You know, I think um to wrap things up, I would like to kind of zoom out and think around a similar theme. Um, envisioning a world, I guess, in which humans have worked out some better ways of relating to plants. What do you see? What's kind of a vision of uh, let's just say, a city for an easy boundary, this city that you know people are getting along better with plants, they're helping that foundational part of the ecology and being better neighbors to it.

Bonnie Isaac:

Well, one of the things that we could do to be better neighbors for plants in that is to not give people tickets for not mowing their yard and encouraging native plants so that we have native pollinators, birds, and native animals have passageways to get from one block of woods to another, you know, so that we can like encourage their habitat to be nicer for all of us.

Michael Pisano:

Punish people for something that's probably not, you know.

Bonnie Isaac:

No, not punish people for doing things that are probably good for the environment, more than mowing and having acres and acres of monoculture grass where you're not going to have very many birds or insects, you know. So we just need to encourage governments to uh encourage citizens to take care of the ecosystem.

Michael Pisano:

Gotcha. So in this kind of utopian, plant-friendly city, we've got top levels of you know systems that say, hey, it's good for you to do this and you disseminate the right uh information instead of maybe some outdated ideas about keeping nature at bay or out. Right. Wonderful. Yes.

Mason Heberling:

What do you see in this city? Yeah, what Bonnie said. Um yeah, no, I mean I think also just the importance of of green space, I think, for for both for human health but also for plant health. I think they're kind of one and the same a lot of times. And so trees are good. Trees are good in a lot of different ways. The importance of just having shade is is um becoming even more important. So yeah, but that's not to say it doesn't like come without work, and in in today's today's world, I mean it comes with some intent. So it's not just to say, oh let let's reduce the amount of pavement and just let things happen. Because in the case of like like knotweed, for instance, and and other things, um, it's kind of hard to look at concrete, you know, parking lot area and say, we should have all these, like this this is a native habitat. Like what I don't know, ultimately, like the city isn't a quote native habitat. Right. It is a very different habitat. So we can't like get upset that we can't plant this rare plant that Monty has in in the parking lot of the museum. But I would think we there are certain kind of urban planning things that could be done to make it such that we have green spaces that maybe plants like like this can flourish even in urban settings, but also just maximizing the amount of local ecology that can happen in a city. And I think through green space and your own lawn has an important contribution, it's pretty surprising just planting a couple, a couple hot plants for pollinators and hummingbirds that they show up even in the middle of the city. Yeah, it really is kind of like each vote counts, and in this case, it really does. It's like doesn't take much, honestly, and then it's addicting. And if you've got a good thing going, the plant, the plants also. I mean, I say it's you know, you kind of have to do some curation, but it really does the the plants do it themselves and they spread on their own, and like it's a miracle.

Michael Pisano:

It's the original vegetative miracle, right? It's like there's something so you know ecologically beautiful and you know that we rely on, but it's also spiritually extremely filling, I think, to be surrounded by plants. And um we really miss out.

Bonnie Isaac:

I think there have been studies done that show that people who go outside and interact with plants are healthier.

unknown:

Definitely.

Michael Pisano:

Yeah, no doubt about it. Um great. And so just to kind of take us out, are there any people already doing some aspects of that good work that you want to plug or you know, say, hey, if you want to get involved in this, you're not sure where to start, you don't have to do it alone. Who should we look to?

Mason Heberling:

Support your native nurseries, I guess I would say, and support your land trusts, your local um parks and and things like that.

Bonnie Isaac:

Right here in Pittsburgh, we have Tree Pittsburgh, which will help get trees out and about.

Mason Heberling:

And you know, in the Pittsburgh area, we also have like Allegheny Land Trust, for instance, Audubon Society, Western Pennsylvania has a uh native plant center, for instance, and they provide a lot of important information as well. There are resources out there that are only increasing, and they'll increase with with your and with your interest, you know.

Michael Pisano:

Excellent. Thank you both so much for spending this time taking us again behind the scenes of the collection. Appreciate you both.

unknown:

Thank you.

Bonnie Isaac:

Thank you.

Michael Pisano:

Approximately 550,000 thanks to Bonnie and Mason for inviting us into the Carnegie's botany collection and to the amazing plants therein for inspiring us to grow towards better futures. This whole season of We Are Nature was recorded in one of the museum's barbarian spaces, just about 15 feet away from Mason's office. Mason, many, many thanks to you and the rest of the botany crew for your most excellent hospitality. We are Nature is produced by Nicole Heller and Sloan McRae. It's recorded at Carnegie Museum of Natural History by Matt Unger and Garrett Schmidt. DJ Thermos makes the music. Mackenzie Kimmel describes the collection items, and Garrett Schmidt and Michael Paisano. That's me for edit the podcast. Thanks for listening.