pressing plants, with herbarium curator linda lipsen

I SAW NEWS of a new book called “Pressed Plants” recently, and it got me thinking about my grandmother and one of the many crafts she enjoyed way back when. Grandma made what she called “pressed-flower pictures,” bits of her garden that she carefully dried, arranged on fabric and framed under glass. And some of those still hang on my walls. It also got me thinking of the 500-year-old tradition of pressing plants for science and the herbarium world.

Whatever the intention, pressed plants are the subject I discussed with Linda Lipsen, author of the book “Pressed Plants: Making a Herbarium.” Linda presses specimens in the name of science as a curator at the University of British Columbia Herbarium in Vancouver. (Above, a mounted specimen of Lilium leichtlinii from the UBC Herbarium.)

She’s carrying on a method of recording the botanical world this way as humans have for centuries. We talked about what information those centuries of pressings hold for us in today’s world and how and why we gardeners might want to give pressing plants a try, whether for art or for science.

Plus: Comment in the box near the bottom of the page for a chance to win a copy of “Pressed Plants.”

Read along as you listen to the Aug. 28, 2023 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify or Stitcher (and browse my archive of podcasts here).

pressing plants, with linda lipsen

Margaret: We’ve had fun. We did a “New York Times” garden column about this world of craft and science of pressing plants and what they mean to all of us in different ways. I’ve just been enjoying your book enjoying so much. It’s so practical and also gives all of the reasons behind it and some of the history, so it’s really fun.

Linda: Oh, thank you. That’s great.

Margaret: And so the backstory of my getting in touch with you recently to pester you and learn more [laughter] was that I have these pictures that my grandmother made 60 or so years ago on my wall [example below], and I’ve always known about “pressing flowers,” as she would call it. And then I know about herbariums because of my work all these years and wonderful places with all these archives and so forth of history, and I just want to learn more. And so I contacted you.

So what purposes do herbarium specimens serve? What do you learn from them and so forth? Because it’s this old tradition, as I said in the introduction, like 500 years people have been doing this. Yes?

Linda: Yes. So herbariums do have a long tradition, and a lot of it originally came from medicinals. So this was when the people who were taking care of the communities needed to be able to collect and make extracts for curing different ailments. And when they started to do this, they realized that trying to transfer that information to the next generation, or the next student, they would actually talk to them and say, “Oh, well why don’t you go out and go get that plant over there that’s got a blue flower and a green leaf that’s kind of shaped like this,” and that just really wasn’t enough. [Laughter.]

There’s too many things with blue flowers and this kind of shaped leaf. So to be able to make a specimen meant that you could actually really document what this plant really looked like, right? And all of its different stages, so not just in flowering, but also in fruit, because of course fruit becomes incredibly important for a lot of these medicinals. And so that was actually a really great way in which to start storing this information.

And then also what a lot of people don’t think about is many of these populations actually have different levels of extract. So even if all these plants are making these different chemicals that could be useful for us, different populations might have different constraints or strains on them because of predators. So they might make more of this extract. And so you actually start to get into populations with that kind of documentation. So it’s pretty astounding it’s been around for so long, but now it’s just opened up a wealth of information that I don’t even think the first person ever even dreamed of.

Because of course, nowadays in the modern age we can extract DNA, and so the level of extractions for plants and now out of a dried specimen, we can extract this DNA, it’s giving us more information than ever before.

Margaret: So I didn’t realize that the original impetus was medicinal; I didn’t know that. That’s really interesting. And you were just saying that for instance, different populations of plants might have more or less, because when herbivorous predators come to nibble on something, whether it’s an insect or an animal or whatever, I mean the plant has a self-defense that it mounts and it may make more, as you said. And that’s interesting because well, I just hadn’t thought about why that is one of the reasons behind…

Linda: The thing is I did population genetics, so of course I thought a lot about this. And being in the collection scene, the way people collect is always kind of fascinating, the way people collect certain populations and not others. And so yeah, medicinals were the beginning. It was the original doctors.

Margaret: So do you get calls or emails or whatever from other institutions that say, “Can we look at your specimen of such and such?” I mean, is there cross-comparison among institutions, because there’s all this history and some of these places are just massive. I mean, I’ve been to the one at New York Botanical Garden in the Bronx, and it’s like, whoa. I mean, I don’t know how many zillions of mounted specimens are in that collection.

Linda: Yeah, I think they’ve got a couple of million in their collection. It’s amazing. And we have cross-pollination; we have tons of cross-pollination. We exchange material all the time. So we have kind of two different systems we loan to anyone in the world. You just have to be at an institution. So I could even loan a specimen to you if you wanted to go to New York Botanical Garden to examine it, because it’s a safe environment.

I also do exchanges. So we actually collect and we want everybody in the world to see our cool stuff in our environment. And so we’ll collect extra species and we’ll send them off to different institutions if they want to have examples of what’s in our flora so that we can have comparables, right?

Because when you don’t have that exchange of information, you can get very isolated, and you can make mistakes, because you’re not really looking at the flora around the earth, you’re only looking at it in your region. And so to have those exchanges going on is incredibly important to keeping the information flow between researchers, but also artists, historians, again, whoever wants to access these collections, they’re open.

Margaret: Exciting. So in terms of what we can infer from it, and especially in such fast changing times as we’re in right now, I mean, you’re in British Columbia and I mean you’ve been experiencing a lot of drastic fires and all kinds of things going on, speaking of things that would change plant populations or their ranges potentially or who knows what impact. And I think it’s one of the things you’re interested in is the shifting ranges of plant populations.

Are you comparing to X-hundred-year-old specimens when you do new collections in some way to say, oh, this is what happened, or there’s this new invasive present that wasn’t here the last time someone collected here. Is that also done?

Linda: Yes, and it’s amazing because this is one of the things that I love about herbariums. So they are just time shots of earth over a long period of time. So they’re the timekeepers of our biodiversity on earth. And so we are able, depending on how much people collected and how good their notes were, we’re able to track. So I have a great example of John Davidson, who was our founder, and he made a little note about an invasive that’s in the Okanagan, which is a quite beautiful ecosystem here. It’s actually one of our only deserts in Canada. And he noted that there were three individuals in this area of the Okanagan. We now, because of that note, can map how much spread has happened over the last 120 years because of that note on the specimen, right?

Margaret: Wow.

Linda: Yeah, I know. And then we have things like, we are definitely shifting. We are losing tree line, so more species are going higher up in elevation. We also are having broader extensions. We’re also seeing loss of habitat where we know certain plants are not going to be able to make it because their habitats are actually disappearing. So we are, we always are going out and collecting and trying to add information.

And then on top of that, there’s crazy things that are in these collections, like we’re noticing flowering time changing. So we know that seasonality is changing, and that the plants are responding to that. And then also sizes of things. Things are either getting bigger or they’re getting smaller. And we’re able to see those fluctuations of morphology over time, which actually again can affect the health and the longevity of these plants and other species that we’re noticing this with.

Margaret: Wow. A lot, lot of inferences to be drawn. In your book “Pressed Plants,” I read about one example of a type of collecting, I guess a strategy or something called I think “first bloom, last bloom” records. And it made me, speaking of what you were just saying, about I guess it would be called the phenology or whatever, the timing of what’s happening when.

I mean, I’ve been in the same garden 35 or so years, and so I know there have been shifts instinctually, but I don’t have the data in all cases, unless I find old journals or something. And so when I read about that first bloom, last bloom record keeping… tell me about that.

Linda: So I love this one. So what a lot of people who I know who start getting into this, what you love and I think we all love is first bloom. Because when we see first bloom, we know spring is coming [laughter]. And so for me it’s always like, “Oh, first bloom, first bloom.” And for us it’s actually fairy bells. It’s a beautiful little shrub here, and I’m always waiting for the fairy bells to come out.

And so I’m always looking for first bloom. And I love what you said, Margaret, because I think a lot of us who’ve been gardening for a long time, we have seen these shifts. We feel them in our bones, we see them in our gardens, but yet we haven’t documented it. But there have been people who have been documenting this. And so they go out and they look for their first blooms, and we see that shift, whether it’s later or earlier. Some species are reacting to the climate change differently.

We’re also now doing even more detections; even if there’s an early frost in February, that can really affect again the development that’s going to happen later in the spring. And then what I really love is as we know, we get really hot now in June and July at this extreme level, sometimes August as well, but in the Pacific Northwest, we’re now going to start a cooling period and a lot of things will re-bloom.

And I think people forget that, that there’s these re-blooms that happen once it cools off and we get water again. And that’s been a fascinating thing to see how long that will stretch out and what’s the last bloom you see of the season. And that can really give us these… Scientists need these extremes so that we can start to do the statistics of when are things really blooming and what are these shifts really happening? And we’re seeing it all the time. And it’s really lovely when people document these kinds of things, either in notebooks, people have floras, and they document first bloom, last bloom in there, and over time they’ve seen these shifts of the dates to earlier.

Margaret: So the book is kind of a how-to guide to pressing plants. And it also gives, as I said earlier, some of the why behind it and some of the history. And when we did the time story together, we also talked to a woman with a craft-based business. She presses things and makes artworks of bridal bouquets and other memorabilia kind of things, sentimental things for people, memory keeping. Lacie Porta is her name, of Framed Florals in Brooklyn. [A finished artwork between glass by Lacie Porta, above.]

And so I was thinking about your process and your book, and her process, and my grandmother’s process. You all have a wooden press, and it was always filled with lots of layers of absorbent kinds of paper [laughter], but there are some differences as well. So I want to talk a little bit about the sort of the process, the basic process.

If people want to give it a try. I mean, what is it that we’re trying to do? I mean, Grandma just stuck some in an old giant phone book sometimes [laughter], but she also did have a wooden press.

Linda: And that’s the thing. It’s funny, I have a little video I’ve been making trying to extend on the book. And one of the things I found is that I only have one press actually, and that often is in transit to do lots of different things, different collections I’m doing. And I was doing this one press because I wanted to make some cards for a thank you for my book, for my editors, and I didn’t have my press with me because it was at work because I had some other specimens drawing. And I take books just like everybody else. So I just put them in with the blotter paper and I just put my books on top. And that’s the best weight you can have. Books always are great, and that’s again why this is such an accessible science.

The tools are a little different, but what you’re really trying to do is just draw that water out. The idea is that the water in the cells is what’s going to make your specimen go black or be discolored. So you want to slowly draw it out. You don’t want to draw it out too quick, you don’t want to cook it in an oven or something like that. People have tried lots of different things. But really the blotter paper, paper that’s really absorbent. Newspaper is not great anymore, but even paper towels are quite absorbent. The only problem with paper towels is they can leave a texture, which is why you have to be careful with paper towels; they leave that extra texture on there, which is why the blotter paper is so nice. But blotter paper is expensive, but you can reuse it over and over and over again.

Margaret: So this is right up against the specimen. And if you have a big thick press, the other layers can be other things. It’s not like you have to have 500 sheets of blotter paper or something.

Linda: Not at all.

Margaret: Right? A top and bottom surrounding the specimen. Blotter paper? O.K.

Linda: Yes, to extract that out. Now, of course, we had talked about before that in the science world, we do use the newsprint, and it’s mainly because we’re processing a lot of specimens at once. So when we go out, we’ll collect about a hundred specimens. We need to push those through a system. So we’re not only drying them, but we’re also having to keep them really well organized. And to do that, we usually shift them through the newsprint so that we can keep track of who’s where. So it’s a kind of helpful thing. But for the gardener, I do this all the time. I go out, I collect things in my garden, also even when I’m collecting plants, you want to use that paper and the press, you need pressure on there.

I’ve talked about cell death. So when you go to put the specimen in and you start to dry it, I usually squish it pretty hard. And then I open it up a couple days later to have a look, and I’ll start rearranging if I feel like I need to see the stamens or the sepals in the middle, I need to remove a petal because it’s got this really important design on the inside of the petal that we need to see for taxonomy. And then I close it back up and I just let it dry for about five days, and I get the specimen I’m looking for. And again, if it doesn’t work out, then I make cards [laughter]. I make bookmarks, I make gifts. It’s the best part. There’s no waste in my job. It always goes towards something more creative and fun. [Above, plants going into Linda’s field press between newspaper layers.]

Margaret: You just were speaking to the idea of you might a couple of days later take one more chance before it’s really dried to move things around a little bit. And that’s one of the differences between you and Lacie, who we talked to at Framed Florals in Brooklyn, because she might take apart a flower because her creative idea for the end product is to rearrange the petals. Or because the center of the flower, imagine a rose or a coneflower or sunflower is so thick, it’s going to dry on a whole different schedule, if at all, and it’s not going to get flattened and go between glass.

So she may be taking artistic license, which is great, but you’re trying to document and show us this record for the centuries ahead of an accurate… And you were just speaking about for taxonomic, for identification purposes and seeing the reproductive parts, seeing anything that’s important, all the important parts. And so it’s not as pretty, pretty, it’s as accurate, accurate. Right?

Linda: And it can be really frustrating when you first start. And this is why I really wanted to do the book, because I love the work that these artists do, and I get so jealous that they can pull apart these flowers individually. And like I talked about you lay them all out, they’re just gorgeous, they dry at the same time, they behave, and then you get to put them all back together like a puzzle.

And you can arrange them so much more lovely than you can in my case, where you really have to keep all the parts attached so that we can see if it’s opposite or alternate leafing, if the toothing of the leaves, even the thistles and all the little parts that you don’t want to touch. And even when we press cactus [laughter], it’s super-painful, seriously. But we have to keep all the spines and we can’t take those off no matter how much they punch through the paper and the cardboard, right?

Margaret: If you have a fruit, I think you told me, you have to squish it, you have to know how many seeds are inside that fruit, right?

Linda: Yeah. We need to know if it’s a pit, or what the inside looks like, and this is where that parchment paper or that wax paper comes in so that you can… I often do this with raspberries and things like that. I’ll have to stick it in there and it doesn’t look pretty, but it tells me how many seeds are inside. And taxonomically really important for us.

Margaret: So again, Lacie making her artworks for her clients, she wouldn’t be doing that [laughter]. And so you’re using, surrounding those juicier, stickier materials like that, you’re maybe using wax paper before the blotter paper. You’re giving it a chance to stay unstuck and so forth at first, or like you said, parchment is another possibility.

And then in between, I saw that you turned me on to an interesting supplier of everything from presses to glue to who knows what, called Herbarium Supply Company. And the presses are quite inexpensive. They’re sort of two layers for top and bottom of lattice wood and a strap with a adjustable kind of, I don’t know what you call that, but you can tighten it, and they’re not very expensive. And then you put corrugated cardboard and newspaper layers and so forth in between. Is that basically all you really need?

Linda: Yeah, that’s the best part about it. And like I said, we all start off with books and that’s completely valid. There’s nothing wrong with using a book. But the presses, and this is the difference, too, if you notice a lot of craft people will use the press, and you’ll see this in Lacie’s picture where it’s the screw-down type [above, a press at Lacie Porta’s Brooklyn studio], it’s more of a craft type, and that’s one that’s going to sit somewhere. Whereas I’m moving, so I’m in the field for 10 hour days, and I have to be pressing while moving. There’s different ways to do this depending on how far out I have to go that day. So I actually have my press and it’s portable, and this was always the idea is that this press is very portable.

So we have the early collectors, of course, the really early collectors were going out for months at a time, still coming back to press. But it had to be movable. You had to be able to strap it onto your horse. You had to be able to move it with you at all times. And my press actually, I have very long, a lot of people use rope, I do use the straps and they’re cloth straps. I’m biased towards cloth straps, but I actually tie it and then I can actually put it on a backpack so that I can walk around with it and then get to my next spot and then sit down, take all my samples, put them in my press, and then keep moving for the day.

Margaret: It’s a field press. Yeah, definitely. You told me also that you started in this as a volunteer 30 years ago, mounting specimens, I think at a community college in Oregon. And is there still an opportunity for laypeople, like gardeners, to engage with a herbarium like where you work?

Linda: Oh yeah. Oh my gosh, yeah.

Margaret: Tell us about that, because I was surprised. I didn’t know [laughter].

Linda: We run on volunteers. Herbariums are notoriously, they are underfunded, but it makes us creative. And it also, to me, you just turn on opportunity. And so it means an opportunity for people to come in. So I have a team of volunteers. Every year I do an email out to about 20, 25 people, and they come from all walks of life, people who are retired, people who are students at my university. And we all get together in a room, and it’s one of my favorite things, and I kind of talk about this in my book, but it’s like a knitting circle.

So we all sit around and we mount specimens. And mounting specimens is absolutely the most therapeutic thing. So processing a specimen and processing its data is not always the most therapeutic thing, but mounting it and finalizing it, these students get to sit and read these labels about these beautiful specimens that were collected in remote areas by amazing collectors, and they get to tape them down and glue them down and arrange them in these beautiful manners that I put on my Pressed Plants Instagram, because I like to show this creative side that you can do at the end.

And we all talk about our life, we all talk about our day, we all talk about the podcasts we like, or the movie that was really cool, or the class to not take. There’s a lot of mentorship that happens in that room, and it really allows this closeness to happen and it allows everybody to slow down for about two hours.

And that’s really what I want to bring across to almost everybody is one of the reasons I want people to press plants is you slow down; you just slow down. And it’s lovely and it’s shareable and it’s easy to access and it’s everywhere. So anybody can contact their local herbarium.

There are 3,500 or something like that herbariums in the world. They’re everywhere. You wouldn’t even realize it. It’s in your backyard. Everywhere there’s an herbarium. And yeah, I started as a volunteer and it was the best thing I’ve ever done.

Margaret: It’s so interesting. I mean, because I would have thought you became a botanist and then that’s how you ended up working in it. But it was quite different. It was quite the other way [laughter].

Linda: Yeah. I was just taking a class and I saw somebody in a room and I was like, “What are you doing?” And they’re like, “We’re mounting specimens.” And I’m like, “What’s a specimen?” And it just starts from there. That was my Friday and it was my favorite day of the week was Friday for two hours mounting specimens. [Above, a mounted specimen of Scilla siberica from the UBC Herbarium.]

Margaret: Well, it’s pretty wonderful, and it’s been fun to learn more of the history as well. So just really quickly, when’s your next sort of field adventure? Where are you going? Going somewhere locally, or far?

Linda: So we’re going up to Squamish tomorrow. It’s a beautiful area that a lot of people go to up here near Vancouver. And we were just on iNaturalist. I’m working with an amazing student on a rare and endangered species across Canada called Bidens.

Margaret: Oh sure. Bidens, sure.

Linda: It’s a sunflower. It’s quite cute. But we are now detecting on iNaturalist that there’s some populations that have never been documented. So we’re going to head out and see if we can document some of these sites again, taking specimens, pictures, fitness measurements to see how they’re doing. And so that’s where I’m heading out tomorrow all day. Beautiful Squamish to collect gorgeous Bidens.

Margaret: Well I’ll be looking on Instagram to see what’s next. And thank you Linda Lipsen for making the time today. And I’ll talk to you soon again, I hope. Thank you.

Linda: Thank you so much for inviting me, Margaret. This has been a blast.

enter to win ‘pressed plants’

I’LL BUY A COPY of “Pressed Plants: Making a Herbarium” by Linda Lipsen for one lucky reader. All you have to do to enter is answer this question in the comments box below:

Have you ever pressed any plants or their flowers? Tell us.

No answer, or feeling shy? Just say something like “count me in” and I will, but a reply is even better. I’ll pick a random winner after entries close at midnight Tuesday, Sept. 5, 2023. Good luck to all.

(Disclosure: As an Amazon Associate I earn from qualifying purchases.)

prefer the podcast version of the show?

MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 14th year in March 2023. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Aug. 28, 2023 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify or Stitcher (and browse my archive of podcasts here).