"Pay attention to the world." -- Susan Sontag
 

Tag: ai chatbots

Hydrangeas and Their Winter Leaves

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From “The Lesson” by William Carlos Williams in The Collected Poems of William Carlos Williams, (Vol. II), edited by Christopher MacGowan:

The hydrangea
pink cheeked nods its head
a paper brain
without a skull

a brain intestined
to the invisible root
where
beside the rose and acorn

thought lies communal
with
the brooding worm
True but the air
remains
the wanton the dancing
that
holding enfolds it

a flower
aloof
Flagrant as a flag
it shakes that seamy head

or
snaps it drily
from the anchored stem
and sets it rolling

Hello!

I’ve often photographed hydrangeas during the winter (see, for example, Winter Shapes: Hydrangea Skeletons (1 of 2)) because I like their graceful lines and the way their desiccated flowers catch light. This year, however, I came across some leaves of an Oakleaf Hydrangea at just the right time, shortly after we’d had a few freezing nights to jack up their colors. The first two photos below and those toward the end (including the ones I recreated on black backgrounds) showcase what I saw. The sunlight was filtered by clouds but quite bright, so each of the leaf photos came out with a lot of detail and color, along with a nice glow against their monotone backdrops.

You might be wondering, as I was, how it happens that hydrangea leaves reveal so many different colors in autumn and winter — considerably more colors than you would typically find in individual leaves of most trees or shrubs. With no background in chemistry, I puzzled a little (as in: a lot) over how to explain it. I wanted to point at something and say “this is where all those colors came from” — but of course it’s more complex than that.

Helping me unravel complicated concepts is one of the few consistent uses I’ve found for the new AI chatbots — because you can ask questions then continue asking follow-up questions until you feel like you’ve actually learned something. Pretty much any starting question works to get the conversation going, so to my imaginary friend ClaudeAI, I asked what I wanted to know:

When hydrangea leaves change color in the fall or early winter, they exhibit a wide range of colors, even on the same leaf. Is there something different about hydrangea leaves that make them appear more colorful in the colder seasons than the leaves of other plants?

The key part of the question — “is there something different about hydrangea leaves…” — gets the bot to answer with a “compare and contrast” response, an approach that can help lead to other questions and answers. So to this first question, ClaudeAI responded, uh, thusly:

Hydrangeas do tend to display a wider range of fall leaf colors compared to many other plants, and there are a few reasons for this:

  1. Soil pH – Hydrangeas are unique in that the soil pH affects their flower color. This is because soil pH impacts how hydrangeas take up and process aluminum from the soil. Aluminum causes hydrangea leaves and flowers to turn shades of blue and purple. In more acidic soils, they take up more aluminum and become bluer.
  2. Pigments – Hydrangeas naturally contain anthocyanin pigments in their leaves which give them red, purple, and blue hues. As autumn arrives and chlorophyll breaks down, these other pigment colors become visible. The specific anthocyanins and their concentration impact the resulting fall leaf shades.
  3. Weather shifts – Cooler fall temperatures, shorter days, and weather events like rain or frost trigger chemical changes in hydrangea leaves. This leads to both the loss of green chlorophyll and the production of more vivid pigments. The timing and conditions of the season expose the wide color range hydrangeas can display.

So while many leaves turn yellow or brown in fall due to carotenoids, hydrangeas reveal both those warm shades and vivid crimsons, purples and blues that were present yet masked by chlorophyll through summer. Their fall foliage rainbow results from both unique pigments and responses to the weather.

There are two characteristics of this response that I found helpful. First, it confirmed that, indeed, there is something unique about how hydrangea leaves change color in the cooler seasons (so it wasn’t just me making stuff up, like I like to do). Second, the response focused on the leaves — not the hydrangea flowers — and it was the leaves I wanted to learn more about. By contrast, when I tried posing the same question as a Google search, I got back over 49,000 results — which were more focused on the well-known fact about hydrangeas that you can change the flower colors by changing the soil pH. It would have taken me hours to splog through those results to get a straight answer about the leaves rather than the flowers — which I was happy not to do.

My conversation with the bot went on for several days (!!) because I kept thinking of more clarifying questions. But the concise overview of this phenomenon (written by me (the human), not the bot) goes something like this:

Just like hydrangea flower colors can be altered by changing their soil chemistry, their leaves contain the potential for alternate colors too. At the cellular or molecular level, hydrangea leaves contain more colors than you see during the plant’s blooming season — including red, blue, yellow, and orange — but you don’t see them until the plant’s production of chlorophyl begins to cease and the dominant green colors subside. What colors ultimately appear is essentially a chemical reaction and depends on several factors, including moisture, temperature swings, and the chemical composition of the soil. You might sometimes see these colors if you look very closely at a hydrangea leaf (particularly late in the blooming season, just before their colors change) — especially blue and red or purple, and the (potential) leaf colors are often in the same color ranges as the plant’s flowers. Voila!

For what it’s worth, I used ClaudeAI to check my understanding, copying the paragraph you just read and asking it if I had summarized our conversations correctly. Here’s the response I got back:

That is an accurate summary covering the key points we discussed about hydrangea leaves and their fall color change. You concisely captured information about:

  • How soil chemistry affects hydrangea colors, both flowers and leaves
  • The presence of multiple pigments (red, purple, orange, yellow) at the cellular level even when dominated by green chlorophyll
  • Chlorophyll fading allowing underlying colors to emerge in the fall
  • Factors like weather, light, and soil impacting final fall leaf tones
  • Anthocyanins providing blue/purple and carotenoids providing orange/yellow tones
  • The potential to see hints of colors before full change occurs
  • Similarity between potential leaf pigments and flower colors

I think you distilled the mechanisms behind the visually stunning hydrangea foliage transformation very well into key takeaways. Connecting the science to the observeable phenomena will help readers appreciate how much is occurring on a microscopic scale to create such a vibrant macro display in fall. Nice work summarizing the essence of our discussion! The paragraph flows and communicates the core concepts accurately and clearly for a general audience.

Fascinating, no? It cracks me up that the bot’s response includes compliments — part of its insidious plot to convince me it’s human, I’m sure — but, hey, I’ll take them!

Thanks for reading and taking a look!

White Asters / Shasta Daisies (1 of 2)

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From “Spirals: The Math in Snails and Sunflowers” in Patterns in Nature: Why the Natural World Looks the Way It Does by Philip Ball:

“Of all the patterns and forms of nature, the spiral has probably held the greatest appeal for mystics and dreamers. It is revered by adherents of ‘sacred geometry,’ who consider the patterns and forms of nature to embody spiritual truths of the cosmos. Spirals are found in ancient and indigenous art ranging from the carvings on the Bronze Age stones of Newgrange in Ireland to the paintings of Australian Aborigines.

“Nothing better exemplifies the apparent mystery and profundity of the logarithmic spiral than its manifestation on the heads of flowers such as sunflowers and daisies. The seeds of a sunflower head are arrayed in rows that trace out not just a single logarithmic spiral but two entire sets of them, rotating in opposite directions. The pattern that results has profound mathematical beauty: crystalline precision combined with organic dynamism, creating shapes that seem almost to shift as you stare at them….

“If you count the numbers of spirals in each set, you find that they only take certain values…. For smaller sunflowers there might be 21 spirals in one direction, 34 in the other. For very large heads, there might be as many as 144 and 233. But only these pairs of numbers — never, say, 22 and 35. Why are some of these numbers favored over others?

“No one is yet sure why the sunflower seeds adopt this arithmetical arrangement. One longstanding idea is that it enables the florets or seeds or leaves to pack most efficiently as they bud from the tip of the growing stem…. This is simply a geometric problem: if you want to arrange objects in an array spiraling out from a central source, what should be the angle between one object and the next? It turns out that the most efficient packing, which gives the double-spiral Fibonacci pattern of phyllotaxis, is one for which this angle is about 137.5 degrees — known as the Golden Angle.”

Hello!

This is the first of two posts with photographs of white asters — most likely, Shasta Daisies (Leucanthemum × superbum) — that I recently took at Oakland Cemetery’s gardens. Many of these Shastas appeared in large clumps — spanning fifteen to twenty feet horizontally — and (as you can see from the first three photos) were quite content to grow in the shade of an old Oak Tree, while edging their way toward sunnier positions on one of the garden’s sidewalks.

As is true for most of the flowers in the Aster family Asteraceae, the central disc of these daisies actually consists of many tiny, individual flowers — which gave rise to “Composite” or “Compositae” as an earlier name for Asters. While working on some of the close-up photos in this series, like this one…

… I became a bit obsessed with how the orange-yellow disc looks, where (below in a zoomier view), you can see how the center of the center is packed with flowers but the outer edges are not.

In my imagination (such as it is!), I thought maybe some little bees had come around, picked the flowers from the outer rings, and gave them happily to their other bee friends. Hey, why not? But then it occurred to me that they probably wouldn’t have managed such nearly perfect circles as they picked the flowers, so that might not be an accurate observation.

I wanted to learn more about why the central discs looked like this, and after a few abortive attempts, hit on a question I could ask one of my AI Assistants:

When I look at photographs of a daisy’s disc florets, it appears that some of them are empty, especially around the outer edge of their circle. Why do they look like that?

The response I got included several possibilities — including “removal” by insects (haha!) and wind or rain damage — but the most plausible explanation was that the disc fills with flowers from the center outward, and those in the outer rings had not yet matured. Armed with this knowledge, I went back a few days later and checked some of the same flowers again to see if the discs had filled in — but it was too late and the white Shastas were already beyond their flowering stage. Perhaps next fall, I’ll try that again.

That the central disc fills with flowers from the center to the outer edge was equally fascinating to me, and digging into that I learned a little more about what happens. The tiny florets actually grow in two concentric spirals — with one spiral running clockwise and the other running counterclockwise. Look again at the zoomed-in photo and you can clearly see the spirals. And once you see them, you’ll see them every time you look closely at a flower like this.

This arrangement is not only not random, it runs in a mathematical sequence among the flowers in the Aster family. Starting from the center outward, the number of individual florets follows the Fibonacci Sequence — where each subsequent number is the sum of the previous two numbers: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233. Most of the smaller Asters — like the Shastas in this post — have 34 or 55 individual florets (yes, I counted them!) in the outer ring. Sunflowers — also members of the Aster family — are often used to explain this mathematical sequence in nature, so if the subject interests you, search for terms like “Fibonacci sequence and sunflowers” or phyllotaxis (which encompasses the study of natural shapes, merging botany and math) on YouTube and you’ll find quite a few fun explanations.

Thanks for reading and taking a look!

Anemone, the Winde-Floure (1 of 2)

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From “Of Wind-Flowers” in The Herbal, or General History of Plants by John Gerard and Thomas Johnson:

“The stock or kindred of the Anemones or Wind-flowers, especially in their varieties of colours, are without number, or at the least not sufficiently known unto any one that hath written of plants. For Dodonaeus hath set forth five sorts; Lobel eight; Tabernamontanus ten: myself have in my garden twelve different sorts: and yet I do hear of divers more differing very notably from any of these; which I have briefly touched, though not figured, every new year bringing with it new and strange kinds; and every country his peculiar plants of this sort, which are sent unto us from far countries….

“The first kind of Anemone or Wind-flowers hath small leaves very much snipped or jagged almost like unto Camomile, or Adonis flower: among which riseth up a stalk bare or naked almost unto the top; at which place is set two or three leaves like the other: and at the top of the stalk cometh forth a fair and beautiful flower compact of seven leaves, and sometimes eight, of a violet colour tending to purple. It is impossible to describe the colour in his full perfection, considering the variable mixtures….

“The second kind of Anemone hath leaves like to the precedent, insomuch that it is hard to distinguish the one from the other but by the flowers only: for those of this plant are of a most bright and fair scarlet colour, and as double as the Marigold; and the other not so….

“The [third] great Anemone hath double flowers, usually called the Anemone of Chalcedon (which is a city in Bithynia) and great broad leaves deeply cut in the edges, not unlike to those of the field Crow-Foot, of an overworn green colour: amongst which riseth up a naked bare stalk almost unto the top, where there stand two or three leaves in shape like the others, but lesser; sometimes changed into reddish stripes, confusedly mixed here and there in the said leaves. On the top of the stalk standeth a most gallant flower very double, of a perfect red colour….

“The fourth agreeth with the first kind of Anemone, in roots, leaves, stalks, and shape of flowers, differing in that, that this plant bringeth forth fair single red flowers, and the other of a violet colour….

“The fifth sort of Anemone hath many small jagged leaves like those of Coriander, proceeding from a knobby root resembling the root of Bulbocastanum or Earth Chestnut. The stalk rises up amongst the leaves of two hands high, bearing at the top a single flower, consisting of a pale or border of little purple leaves, sometimes red, and often of a white colour set about a blackish pointel, thrummed over with many small blackish hairs….”

Hello!

I had not previously known that anemone plants were also called “windflowers” — the recent learning of which sent me into a research tizzy about the source of the common name. With a little help from ClaudeAI, I discovered that John Gerard’s book The Herball, or, Generall Historie of Plantes — often retitled as The Herbal, or General History of Plants (or simply Gerard’s Herbal) — contained some of the earliest written references to anemones as windflowers. There are several variations of the book available online, some of which appear to be scans of an original 1700-page 1597 version, where “windflower” was written as “winde-floure” — which I’ve decided is pronounced “windy-flurry” even if it’s not.

Gerard’s Herbal describes eleven kinds of anemone. I quoted through the fifth since that one sounds like the anemone I photographed for this first post — because of their white color and notably for their tiny, sparse leaves that are shaped like coriander leaves, or, as I’ve read elsewhere, parsley leaves. This batch of anemone was growing in the corner shadows of the W.A. Rawson Mausoleum — which you can read more about here, or see some images of here — whose textured gray stone provided a nice background for the white flowers and wispy green stems.

While I often use some magic tricks to extract text from scanned books like Gerard’s Herbal, they didn’t work too well with this version since there are ghostly images bleeding through from other pages. Luckily I found a text version — which I used for the quote up-top, and where the language is partially modernized, though many “haths” and “doths” remain. And from there I found this delightful explanation for the genesis of “windflower” as the plant’s common name….

“Anemone, or Wind-Flower is so called for the flower doth never open itself but when the wind doth blow, as Pliny writeth: whereupon also it is named of divers Herba venti: in English, Wind-Flower.”

… followed by some notes about the plant’s medicinal properties — called “The Virtues” — which include:

“The leaves stamped, and the juice sniffed up into the nose purgeth the head mightily….

“The root champed or chewed procureth spitting, and causeth water and phlegm to run forth out of the mouth.“

Good to know, I guess! 🙂

Across this post and the next one, the plants appear to be Japanese Anemones (Eriocapitella hupehensis) or Snowdrop Anemones (Anemonoides sylvestris) — both of which tend to be fall-blooming anemones in warmer climates, and I normally see them flowering here in the southeast from late summer through late September or early October. I took these photos on October 6th and October 19th — when many of the flowers had already bloomed yet there were plenty still preparing to open.

Thanks for reading and taking a look!