an up-close look at how flowers work: ‘florapedia’ with carol gracie

THERE’S THE so-called language of flowers, as in the symbolism or sentiment attributed to a rose versus a pansy or a daisy. And then there’s the actual language of flowers in botany, as in what’s a sepal or a tepal and a bract, or what’s a perfect flower, technically speaking?

Those are some of the many eclectic lessons, both scientific historical and just plant fascinating, that I took away from a new little book with a big name, “Florapedia: A Brief Compendium of Floral Lore,” (affiliate link) by Carol Gracie. We started out pretty geeky, getting a 101 from Carol on plant parts, and then talked about violets’ hidden backup set of flowers and Tulipomania and more.

Carol is a naturalist and photographer and popular lecturer who has written several previous books on wildflowers, including “Spring Wildflowers of the Northeast” and “Summer Wildflowers of the Northeast,” both in my cupboard here.

Plus: Enter to win a copy of her new book by commenting in the box near the bottom of the page.

Read along as you listen to the April 19, 2021 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).

‘florapedia’ with carol gracie



Margaret Roach: I think this new little book “Florapedia” is part of a series from Princeton University Press. I believe there was a “Fungipedia” first, if I recall correctly.

Carol Gracie: Right. That came out last year, and probably in June, there’ll be “Birdpedia,” followed by “Treepedia,” followed by “Dinopedia.” They intend to make a whole series of books based on natural history.

Margaret: It’s fun, they’re little books—they’re kind of a great little gifty kind of thing. The book is an A-to-Z of short entries, all kinds of topics. And if we’re talking flowers and the vocabulary attached to them, maybe we should just start with the word inflorescence. What is an inflorescence?

Carol: Well, an inflorescence is usually thought of by most people as a flower. They will look at for instance, a daisy, and say, “Oh, look at the daisy flower.” But in fact, a daisy is comprised of many, many flowers, as are most members of that family, the Asteraceae or the daisy family. They’ll do the same thing with skunk cabbage, they’ll say, “Oh, the flowers of skunk cabbage are up.” But in fact, skunk cabbage is an inflorescence that is made up of really a modified leaf, that sort of encloses a little ball-like spadix, it’s called, on which are the true flowers, many, many of the true flowers.

So you have to be careful when you’re talking about what is a flower. Sometimes what looks like a flower is actually many flowers.

Margaret: Sometimes it’s like there’s window-dressing, and we can talk about some of the purposes for that, that’s not the… and we say “flower,” if we’re thinking of a florist’s arrangement, “the flower.” But it’s sometimes the more subtle interior parts or some of them aren’t interior, but the more subtle parts that are the actual reproductive. Is a flower or reproductive part, is that what it technically is?

Carol: You’re right, the flower is the reproductive part of a plant. Essentially it has to have at least the male or the female part. In most cases, it will have both, in which case it’s called a perfect flower, which doesn’t mean that it’s perfectly beautiful or anything like that [laughter], it has both male and female parts.

Margaret: Funny. And you just mentioned skunk cabbage. Now that is a perfect, isn’t that a perfect flower. I’m trying to remember. My botany is a little rough sometimes. Is that a perfect flower that has male and female?

Carol: Right. Each one of those little flowers that’s studded on the spadix within that enclosing spathe is perfect. It has both male and female parts. Extremely simple flowers, that’s really, basically all they have.

Margaret: Right. It’s funny because I believe its cousin, taxonomically speaking, Jack-in-the-pulpit or Arisaema—even though they’re related, and even though it has the name Jack [laughter], it’s not a perfect flower, is it?

Carol: That’s true. They’re generally either male or female flowers on its spadix. Occasionally you’ll find a rare plant that has both. I’ve never seen one myself. Usually the larger ones are female, because they need the energy to develop fruits and seeds and the smaller ones are male. [Illustration, top of page.]

Margaret: Right. When people say “inflorescence,” it’s not that it conjures a specific, precise visual. It can be very different, and there are different types of inflorescences. I think there’s racemes and panicles and umbels. There’s these different types of them. As I said, it’s not just one visual. When I say in fluorescence, you don’t know exactly what it’s going to look like. [Examples above from Wikipedia illustration.]

Carol: Right. The inflorescence just refers to the arrangement or the grouping of flowers on the flower stalk. For instance, it may be just a spike in which case little flowers are attached directly to the stalk, but there are several of them. People may refer to it as a flower, but it’s actually several flowers along that stalk.

And if each flower has a little pedicel attaching it to the stalk, then it’s a raceme. There are all sorts of terms to describe how the flowers are attached to the main peduncle or, or stalk, of the inflorescence.

Margaret: You said the ones that, for instance, an example of ones that might have tiny ones right on the stalk, the mint family’s like that. And I think people could get a visual of that if they know anything in the mint family. And it doesn’t have those, do you say pedicel, the little tiny stalks that in some other of these arrangements, other types of inflorescences, each little flower is kind of on a teeny little stalk off the main stalk.

Carol: That’s right. And in some cases, you mentioned umbels, in that case, they are on usually longer stalks that are arranged all at one point on the main stem and come off so that the end of it reaches the same level as the one next to it, and next to it, and next to it, and forms a sort of flat or dome-shaped inflorescence. And if you think of Queen Anne’s lace, that would be a good example of an umbel.

I always think of it as sort of an upside-down umbrella.

Margaret: I love that. I love that in the book. I started to laugh because I thought, oh, of course it is. That’s the architecture if I think of it that way [laughter].

Now it’s kind of dizzying again, racemes, panicles, corymbs, umbels. Oh my goodness. But there must be method to this madness of all these words. The precision has a purpose scientifically speaking, yes?

Carol: It does because many plants in certain families only have one particular type of inflorescence.

Margaret: Right.

Carol: They can use those to define a family by. For instance, in the daisy family, what comprises those many, many flowers that we talked about, for instance, the yellow center of the daisy and the white surrounding petal-like structures, are all part of what’s called a composite head. And the inner ones are disc flowers—they are the center of the disc. And the outer ones are ray flowers. And depending on the species that you’re talking about, all of those flowers may have reproductive parts within them, or some may be sterile and maybe they’re just to attract insects.

Margaret: Right. And that gets to the purpose, and what we call a flower isn’t necessarily the flower—where the action is. In some types, in some cases, probably in a lot of cases, it actually is the window dressing meant to attract the needed insect interactions and so forth.

Carol: In almost all cases that’s true, either by color or fragrance in some cases. But if you think now, if you look out in the woods, if you see that sort of reddish haze that’s out there or in some cases it’s a brownish haze. Those are flowers of the red maple trees or elm trees, and they have very simple flowers.

Surprisingly, even though the red maple flowers are very small, they are often pollinated by insects, because they do produce nectar and copious amounts of pollen that are collected usually by small bees, mason bees in particular are good pollinators. They do produce nectar to attract them as well.

Whereas the elm flowers are strictly wind-pollinated, so they don’t need to be showy at all. They just sort of dangle there and their male parts let the wind carry the pollen away to land on the female parts of other trees.

Margaret: Right. Maybe we should get a little quick tour from you of some floral parts, because some of the words, they almost sound like anagrams of each other—like petal, tepal, sepal. [Below, Cornus canadensis or bunchberry has showy white bracts that look like petals but technically are not.]

Carol: Right, right. I don’t know how those were developed, but the etymology is that the sepals are usually the outer whorl of a flower. If you work your way from outer to inner center of the flower, the sepal’s primary job is to protect the flower while it’s in bud, in most cases.

There are always exceptions to all these rules. For instance, I can think of Hepatica, which is just beginning to bloom now. And in that case, the sepals are petal-like, they’re colored pink or purple or white, and they’re the main attractant for insects. The flower does not have true sepals, it has outer fuzzy bracts that cover the buds before the flower opens.

As I say, there are always exceptions, but in general, most flowers have sepals, which cover the buds. Sometimes they fall off afterwards as with bloodroot, they very quickly fall off.

And then the next whorl of flower parts as you’re heading inward are the petals, and their purpose is generally to attract insects. They’re usually colorful.

Working your way in, will be the male parts, the stamens, which are comprised of filaments and the anthers bearing the pollen.

And at the center is the pistil or in many cases, several pistils, which each pistil is comprised of an the ovary, the structure that will develop into the fruit and contain the seeds, topped by a pistil in many cases, not all cases, and then a stigma, which is the receptive part on which the pollen lands. Once the pollen lands on that receptive stigma, it actually begins to grow a long tube down into the ovary where the ovules are and release sperm that actually go down through that tube to fertilize the egg cells.

Margaret: It’s amazing.

Carol: It’s really a lot more complicated than you think.

Margaret: Right. And again, it’s not just, “Oh, look at the pretty flower.” There’s so much complexity going on. And the coevolutionary history that’s being reflected in the way these parts are structured, colored, showcased, whether they have fragrance, whether they have dot, dot, dot, dot, dot. The coevolution with the sort of partner animals, often insects, it’s just fascinating.

Carol: And sometimes it’s very strict. Sometimes it’s a one-on-one relationship. Only one specific species of insect will be suitable for pollination of that flower. And the insects often use cues, some of which we can see.

They’re often, for instance, on spring beauty, you have the pink lines that head down toward the center, which actually helps guide the insects down to where the nectar is, at a little yellow spot at the base of each petal.

But sometimes those cues are only visible to insects, they form a UV pattern that we can’t see with our eyes. But if you look at it under blacklight or UVA light, they can be seen. And it makes almost a brilliant bullseye that is surprising sometimes in its contrast the rest of the flower. It makes it easy for the insect not to waste its time searching for the nectar, but is invisible to us.

Margaret: I sometimes think of it as like the various patterns on the surface of an airport, the runways and so forth [laughter]. It’s over here, over here or the guys with the lights, holding the lights and shaking the lights and showing the plane where to go.

Carol: That’s what it’s like. That’s a good analogy.

Margaret: Yeah. I wanted to just derail for a second and talk about, sometimes there are flowers that we don’t see. We’ve been talking about ones that maybe would be more visible if we poked around above ground. Sometimes there’s ones that are hidden, like the violets have always fascinated me. And could we talk about those? Are they called cleistogamous? Is that what those are called?

Carol: Exactly. Right. Violets have two kinds of flowers. They have the pretty white or purple or yellow showy flowers that we see and that insects visit, but they also produce another type of flower that never open, down at the base of the plant.

Usually they’re produced later in the season, and they serve as sort of a backup. Say it’s a cold rainy spring and there aren’t very many insects flying at the time the violets are in flower so the plant is not very successful in reproducing. In that case, it can reproduce within that cleistogamous flower, that very tiny what looks like a little tiny flower bud that never opens. It has very simple male and female reproductive structures inside. The male structure pollinates the female structure and it actually produces seeds.

But of course those seeds are not as desirable as those that would be outcrossed [cross-pollinated by another plant] because they don’t get the genetic diversity that you would get just as in animal breeding or anything else. You want that diversity in the genetic makeup.

But not only violets have that cleistogamous flower, but also jewelweed. Later in the year, you’ll find… It’s difficult to tell whether it is a little flower, but I’ve only been able to tell by going back day after day and looking at them, that these are cleistogamous flowers as well. And they can reproduce in that way, and they don’t have the seedpods that spring out and make everybody amazed when they shoot their seeds out.

Margaret: I think there’s probably a word for that, too [laughter]. When seeds are shot around, there’s probably a, a scientific word for that too, because there’s a word for everything.

Carol: Right. Right. I just call it amazing [laughter].

Margaret: Yes, indeed. If the sort of hidden backup set of flowers, simpler flowers down there, is cleistogamous, are the ones above ground, do they have a label, too? Are they called something else?

Carol: Of course they do they’re called chasmogamous.

Margaret: Chasmogamous. O.K., that’s the word of the day [laughter]. Oh my goodness.

Carol: Cleistogamy really comes from the same root as cloistered, they’re sort of protected and enclosed like that.

Margaret: Right. That makes sense.

I wonder in doing this A to Z, this little book “Florapedia,” there were some things you probably knew you were going to put in and others that you didn’t and things you happened on. I’m sure you did lots of research, even though you already had a lot of knowledge. And maybe one topical one, it’s almost the time for them is tulips. There were a couple of entries related to tulips. And I wonder if you want to give us a little, ha ha, tiptoe through the tulips [laughter].

Carol: Sure. Tulips should be blooming in our part of the world fairly soon. I actually have some species tulips growing here, but they’re not quite in bloom yet. They bloom a little earlier than the others.

But the tulip itself is native primarily to Central Asia and to the Balkan region. And they have been favored, once they were brought westward, as prime examples of the beauty of a flower. They are one of those flowers—you mentioned tepals sometime earlier in this talk—that are comprised of six tepals, which is really just a technical term for the outer whorl of three sepals and the inner whorl of three petals, which looks almost identical. It’s used in most members of the lily family, lilies themselves, daylilies, tulips. They have six tepals. The reproductive parts are easy to see in tulip and they are incredibly beautiful. The tulips have been developed by humans from 75 wild species, to now about 6,000 registered cultivars.

Margaret: Wow.

Carol: There’s a great demand for tulips, and this demand was at its peak back in the early 1600s, during a time that’s now referred to as Tulipomania. It was probably the first big financial bubble. And at that point, tulips could sell one particular bulb could sell for maybe somebody’s entire estate or property would be exchanged for that one bulb. That’s how important they were as a status symbols and as prime garden plants.

And those that were favored, strangely enough, were those that suffered from a virus, which was not known at that point, but they were the ones that developed these maybe red and white or purple and white streaked petals. They’re called broken tulips.

Margaret: Broken.

Carol: Because the pattern is broken like that. And they were often portrayed by the Dutch still-life painters. in many of those old paintings. But it was stand that that streaking is caused by a mosaic virus, which in fact is detrimental to the plants over all. Eventually they will spread that virus to other plants, and the plants will weaken because of it and eventually die out.

Margaret: Right. Was there another one that kind of was a little bit of a discovery for you or something fun that you remember in doing the kind of homework that led to this book? Any other fun ones there?

Carol: Well what was fun was that Princeton gave me free-range as long as it connected somehow with flowers. And so it allowed me to look into historical topics, and topics having to do with art and artists who painted or drew flowers.

For instance, the artists who traveled with the early plant explorers were extremely important because they had no way to take photographs of these things in flower. And often by the time they got what they tried to take back as living specimens back, they were no longer looking as though they were going to survive. Most did not survive, so they just had the pressed specimens. So those botanical artists were extremely important on the early expeditions.

And today, most of that’s been replaced by photography. But with photography, you can’t always show every part of a flower, the way a botanical artist can. Where he or she may take it apart and draw each separate part. Many scientists still like to take a botanical artist with them sometimes. Although these artists are very skilled at working from dried pressed plant specimens, and even taking the dried flowers or pickled flowers and boiling them up to get three-dimensional structure and being able to draw the flower from that.

Margaret: You got to include some of those as entries in your A to Z in “Florapedia.” Well Carol, it’s always good to talk to you. And I look forward to someday before long going on another walk together and actually looking at flowers together in real life.

Carol: Oh, I hope before too long.

(Illustrations except as noted above from “Florapedia: A Brief Compendium of Floral Lore” by Carol Gracie, Illustrations by Amy Jean Porter. Copyright 2021 by Princeton University Press. Reprinted by permission of Princeton University Press.)

enter to win a copy of ‘florapedia’

I’LL BUY A COPY of “Florapedia: A Brief Compendium of Floral Lore” by Carol Gracie, for one lucky reader. All you have to do to enter is answer this question in the comments box below:

Any tulips blooming at your place this spring–“broken” or otherwise? Tell us about them.

No answer, or feeling shy? Just say something like “count me in” and I will, but a reply is even better. I will select a random winner after entries close at midnight Tuesday, April 27, 2021. 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 11th year in March 2020. In 2016, the show won three silver medals for excellence from the Garden Writers Association. 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 April 19, 2021 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).

  1. Caroline W says:

    No tulips here in my beds; had some handsome ones, but a vast family of chipmunks or whatever, got into them all. But I do have an ample display of different colored narcissus right now, that are obviously not palatable to them.

  2. Wendy Henrichs says:

    Yes, tulips outside and inside (my sunlit Iowa garage!). The garage plantings are the ones that are guarranteed to be free from rabbit maulings. :)

    This book looks fascinating. Thanks for the giveaways.

  3. Susannah Barton-Rossall says:

    Hi from North-West England. I do not have any broken tulips, but plenty of others. However, none of them are totally in bloom yet, as we have had some rather cold weather blowing down from the Arctic! Last year at this time, all my tulips were flowering beautifully. Looking forward to some warmer weather this coming week to encourage all the buds to open. xx

  4. margaret says:

    AND THE WINNER IS…Rose. Thank you all for sharing my fascination for this subject, and for your answers.

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