“Daylilies are native to China, Japan, Korea, and Eastern Siberia. Long before the birth of Christ, they were mentioned as an anodyne for grief in the religious writings of Confucius, China’s greatest philosopher. By the fourth century A.D., they were being used to relieve physical as well as mental pain. A Chinese herbal of the period makes extravagant claims for juice extracted from their roots: ‘It quiets the five viscera [the heart, lung, liver, kidney, and stomach], benefits the mind and strengthens the will power, gives happiness, reduces worry, lightens the body weight and brightens the eye…. Now people often collect the young shoots and serve as a pot green. It gives a pleasant feeling in the chest.’ In addition, the thick roots were boiled and eaten like potatoes.
“It wasn’t until the seventeenth century that daylilies became cherished ornamentals for the pleasure garden. In a Chinese gardening treatise published in 1688, author Chen Hao-tzu describes a plant with leafless flower stalks (scapes in daylily parlance) and arching foliage: ‘The flower when it first appears, resembles the beak of a crane, then it opens with six radiant segments, yellow dusted red, opening in the morning and withering by night.’ This description still fits some of the old-fashioned daylilies.
“No one knows by what circuitous path these plants came to Europe in time to be recorded and described in medieval herbals…. However they traveled, the ubiquitous orange daylily (Hemerocallis fulva) and its yellow companion, the lemon lily (H. Lilioaspbodelus) had arrived in Europe by the sixteenth century. A hundred years later, this same pair crossed the Atlantic with pilgrims and took root in American soil. From the eastern seaboard, the tougher, more adaptable tawny orange daylily moved west with the settlers, earning itself the name of homestead lily. And during the late nineteenth century, a root or two of this hardy species wound up alongside the porch of a midwestern farmhouse. Here, it became an object of interest to young Arlow Burdette Stout, whose mother had planted it….
“At the beginning of the twentieth century, a handful of breeders using half a dozen wild species were producing yellow and orange hybrids. Today, hundreds of hybridizers working with an enormous gene pool are producing a thousand new cultivars a year. (Cultivar combines the words cultivated and variety to distinguish garden plants from naturally occurring species.) Previously unknown colors and designs are now emerging from nurseries and backyards all around the country, thanks to Dr. Stout and Hemerocallis fulva.”
Unlike those in the previous post, where they were planted as part of a precisely designed garden memorial…
… I found the daylilies in these photos in one of the “wild” sections of the property, where several different kinds of plants and flowers live together in a transitional space, arranged and layered for visual appeal. Their presence among densely planted variegated grasses produced interesting contrasts between the bright orange flowers and the green and white or gray stripes in the background, while that grass hid most of the daylily stems and leaves. I took about half of these photos using the gray/green grass as a backdrop, then changed positions so I could focus more closely on individual blooms.
The impressive height of these daylilies meant that they were easy to photograph not far below eye level, so zooming in reveals more of the structure and detail than I could capture from a distance in the previous post. Here we get a better look at not only the blended shades of orange, yellow, and red present in each flower, but also get a closer look at their structure. The layered petals appear to unfold like ribbons, with lower petals terminating in flat or rectangular shapes, and upper petals drawn to a point that is common to many daylilies, including the single form of Hemerocallis fulva itself. In early stages of blooming, each flower has a few upright petals surrounding and protecting its young stamens and pistils, which fold down to the lower layers as these reproductive segments strengthen and mature.
The shades of orange in these daylilies are remarkably stable; you can increase or decrease saturation substantially in Lightroom and still end up with an image that contains adequate contrast, detail, and color variation. That’s actually very common among orange flowers, whose colors — spectrally wide-ranging between yellow and red — are densely packed into the flower petals’ cells. Imagine, if you will, how these colors don’t just exist at the surface level, but at multiple microscopic levels stacked on top of each other. Luckily, our eyes (and our cameras) detect and perceive all these layers, even if they don’t actually register to our vision as multi-layered or multi-dimensional.
“The Orange or Tawny Daylily is a vigorous species with large flowers about 5 inches across — orange with darker zones and stripes in shades of red and mahogany — giving the effect of a tawny color, preserved in the Latin epithet fulva….
“In Asia, where Daylilies have been cultivated for thousands of years, they are regarded as a source of food and medicine. The flowers are picked fresh and fried in batter or dried and used to thicken soups. Preparations from the plant are used to relieve jaundice and dropsy and to reduce fever and pain….
“In Europe and the New World, the Daylily has always been cultivated for its beauty alone. The Lemon Yellow was a special favorite in English cottage gardens. Both the Orange and Yellow Daylily were brought to the New World during the 17th century and widely cultivated across the land. The more vigorous Orange Daylily remains a faithful signpost to many heirloom plant collectors, who know that where it grows, an old garden cannot be far away.
“Until the late 19th century, only these two species were grown in America. By 1860 a double form of the Orange — crowded with petals — was introduced from Japan, where it had been noticed by European travelers since about 1712…. In 1897 a new Orange, ‘Maculata’, was added to the pool of Daylilies, offering later bloom and larger flowers with a deep bronze patch on each petal….
“By the 1920s, America had become the leading center for hybridization, the goal being the creation of ever-new types with larger flowers of diverse forms — wavy, frilled petals, for instance — an expanded color range, and a longer blooming period. The old Orange, naturalized along roadsides across the country, was one of the leading contributors to the breeding process….”
Hello!
This is another one of my favorite daylilies to photograph at Oakland Cemetery — which is probably something I can say about all the daylilies that I’ve ever photographed as well as those I haven’t photographed yet, but will.
This is an especially distinctive space among the many distinctive spaces throughout Oakland Cemetery, notable for much more than the orange double daylilies standing tall at the back. When I took this photograph, the steel chain was in place to discourage entry; but in the past, it’s been accessible (note how there’s a rust stain on the top step, where they chain often sets) so I’ve walked up the steps and sat on the stone bench at the right of the photo.
From that position, the space demonstrates how it’s so unique. The use of grass throughout the space is unusual; and that, along with the placement of shrubs and trees around the edges, creates a sense of visual and auditory isolation from the rest of the property. That your sight is contained within its boundaries, and external sounds are effectively muffled to near silence, actually mirrors the design of the entire cemetery, with its acreage surrounded by hefty brick walls that separate you from the busy streets outside. It’s like a microcosm of the rest of the cemetery, one with its own independent architecture. And that architecture includes the use of plants whose appearance will vary with the seasons, since much of the greenery you see here will exhibit rich fall color in October and November.
Many of the designed plots at Oakland Cemetery contain elaborate sculptured memorials — statues, mausoleums, or other structures representing the people memorialized there and aspects of their lives. Note, however, this one contains only a single memorial stone (right in front of the daylilies) — which doesn’t necessarily convert the square into a straightforward garden, but suggests that its designers favored the creation of a contemplative space rather than a simple (or even complex) memorial. From the bench, there’s a sense of peace that unfolds while you sit there — one that is still quite powerful even if you can only observe it from the outside.
Some of the irises I photographed for my iris project made an appearance here a few weeks earlier, their remnants visible among the green leaves surrounding the daylilies. This daylily cultivar may have been bred to increase its height (while doubling its petal production), as some of its stems extend nearly four feet above ground. This was convenient for The Photographer, who — unwilling to jump the chain and invade the space (this time anyway) — used a zoom lens from outside positions to get a closer look at the flowers.
With a zoom lens and limited sight lines, I had to take whatever lighting conditions I could get, which meant that some of the flowers had a lot of sunlight on them when I took their pictures. The effect — which I didn’t notice until I got home — was that the saturated orange from the flowers combined with the yellow that is natural to sunlight caused the flower petals to act like reflectors casting yellow and orange throughout the entire scene. The effect is similar to results you could intentionally achieve in a photography studio, using a yellow or gold reflector to bounce light from the reflector onto your subject.
This level of warmth in an image of orange flowers isn’t necessarily wrong, nor is it uncommon. See, for example, all these images of double orange daylilies that display similar colors throughout the subjects and backgrounds. But I knew — from what we like to call “real life” — that while the stone behind the flower could have been that sandy brown color, it wasn’t. Much of the stone near these flowers was typical of Oakland Cemetery’s stonework: it’s gray to very light blue, with textures that alternate between the two colors. The leaves, too, didn’t seem quite correct; they should have been a more unadulterated green than the yellow-green in this image.
So these two characteristics of the image told me that some color correction was appropriate, to more accurately represent the colors that I saw. In this case, only a simple white balance adjustment coupled with reducing orange and yellow saturation a smite or two was necessary to remove the color cast, clarify the colors, and create better contrast between the blue-gray stone, the green leaves, and the star of the scene: the daylily’s rich orange.
When I last photographed these daylilies in 2022, this was the only family of them on the property. This year, however, I subsequently stumbled across another colony whose flowers were close to eye level and weren’t visitor-inhibited. That enabled me to get some much closer shots of individual flower blossoms and a few photogenic groupings, which I’ll feature in the next post.
“Color is evaluated by the visual sense of light reflected or transmitted by the flower. The term hue is the specific or family name of a color; value is the lightness or darkness of a color; and intensity refers to the brightness or dullness of a color.
“Modern hybrid daylilies have a remarkably diverse color range, especially considering that the wild types from which they have been bred were found only in shades of yellow, orange, fulvous (dull reddish-yellow), and rosy-fulvous. Today, the only colors notably lacking are pure white and pure blue — colors which hybridizers are avidly pursuing.
“The outer portion of the segments, excluding any contrasting edging, is considered the basic color of the flower. The present color range of daylilies includes yellow in all shades from palest lemon, through bright yellow and gold, to orange; red in diverse shades of scarlet, carmine, tomato red, maroon, wine reds, and blackish reds; pink from pale pink through rose pink to rose red; purple from pale lavender and lilac to deep grape or violet; and melon, from palest cream shades to peach to deep cantaloupe.
“Some colors appear to require the presence of genes for two basic colors; for examples, shades of buff, brown, apricot, and peach are thought to be variations of pink + yellow. Near-whites are found among the palest tints of yellow, pink, lavender, or melon. The actual pigments which produce the colors still need research, as does color inheritance.
“The center area of the flower is called the throat. In most daylilies the throat area differs in color from the rest of the flower. Usually it is a shade of green, yellow, gold, orange, apricot, or melon. It can be very small and narrow or it can reach far up on the segments. The very center of the throat is sometimes referred to as the heart and may be a different color; for example, a yellow-throated daylily may have a green heart.”
Hello!
This is one of my favorite daylilies to photograph at Oakland Cemetery, and I’ve gone back every late May or early June for several years to hunt down this particular variety just to take pictures of it again. “Hunt down” may be a slight exaggeration, since it’s easy to find — it’s one of the first flowers to be seen just inside the cemetery’s main gate.
This daylily contains one of the purest examples of the color magenta that I’ve found among those flowers I photograph, many of which appear to be magenta but are actually variations of light red (trending toward pink), or blends of orange and red. When editing photos of magenta flowers like this in Lightroom, you have very little magenta color saturation to work with, partly because it’s not a primary color (like red or blue) with a large number of varying shades or hues. If you try to decrease magenta saturation directly, the magenta will quickly turn nearly white; and if you try to increase its saturation, you’ll end up with a garish pink color that nobody wants to see. To effect accurate perceptual saturation of magenta, you instead alter the primary red and/or primary blue color channels, using Lightroom’s Color Calibration function. Similar (yet less subtle) results can be achieved by increasing contrast, increasing blacks, or decreasing whites — all of which make the image darker overall but also yield the illusion that magenta has become more saturated, with some loss of smooth transitions between shades of magenta, pink, and red.
It’s a fascinating flower to photograph and edit because of these special characteristics of magenta, given its petals are almost entirely magenta with some red tones, especially at each petal’s edges. This combination is one that our cameras and processing programs detect quite precisely, but we tend to interpret more simply, as the color pink. This shorthand approach serves us well, since magenta is a blend of equal parts blue and red, yet there’s no visible color wavelength called “magenta” in the physics of color. These two principles are observable in Lightroom: if you increase either the saturation of primary red or primary blue, the magenta color in these petals intensifies by about the same amount. And if you decrease primary red saturation and increase primary blue saturation by the same relative amounts (say -100% red and +100% blue), you arrive at exactly the same magenta color you started with.
Yet in natural light, even magenta’s limited saturation range responds quite differently to sunlight versus shade. Note how the left image below — taken when the sun was out — looks so different from the image on the right, taken when the sun went behind the clouds. The effect of additional sunlight actually mimics decreasing saturation in Lightroom: some of the magenta color shifts toward very light pink or even white because of the floodlighting effect of the sun, while the shaded version retains the saturation that was evident in the flowers in real life.
This is not to say that the version on the left is more accurate than the one on the right. Both are correct but reflect different lighting conditions, even if one version might be more appealing to some people than the other. I typically prefer images like the one on the right — taken in the shade — because I like the color rendition better, but, more importantly, limited sunlight reveals all the color and texture variations the flower presents. The flower’s minute details aren’t overpowered by the sun and color contrasts (like those of the yellow throat and the green heart) are much more precise. Especially with daylilies, though, you can’t wait too long for your favored lighting conditions, because the plant always lives up to its name, and its flowers disappear in a day!
“The earliest varieties of irises grown and appreciated by gardeners in the 16th and 17th centuries were likely wild hybrids between Iris pallida, the source of lavender pigments, and I. variegata, the source of yellow pigments. Early collectors gave them various names, some pawned off onto botanists as species names like I. amoena, I. squalens, and I. neglecta. Each represented a relatively distinct color group, but the variation seen between clones was highly suggestive of their hybrid constitution. These seed-grown bearded irises were variously distributed across European gardens from the mid-17th century on. It wasn’t until the 1820s, when Parisian nurseryman Paul de Bure raised and named hundreds of seedlings, that the movement to popularize bearded irises gained a footing; ‘Buriensis’ (c. 1822) was his first introduction….
“By the 1870s the bearded iris fascination had crossed the English Channel, and early enthusiasts like Peter Barr were leading the production of new varieties in the British Isles. It was in the 1890s that many breeders, churning out dozens of new varieties each year, began to wonder if they’d reached the limit of the bearded iris’s potential. One of these was Sir Michael Foster, a professor of physiology at Cambridge and by all accounts among the most esteemed iris connoisseurs of his day. Foster grew and experimented with all irises, including oncocyclus irises from the Mideast and spurias….
“The American interest in bearded irises originated with diploids. Bertrand Farr, a music shop owner from Pennsylvania, imported Peter Barr’s entire collection (over 100 cultivars) and established a nursery near Wyomissing in the early 1900s….
“As America was catching the initial round of bearded iris fever, a schoolmaster from Godalming, U.K., was feverishly making crosses of his own. William Rickatson Dykes is the undisputed godfather of the genus, a position he earned partly through his association with Sir Michael Foster, a friendship begun at Cambridge while Dykes was a student there. Upon Foster’s death, Dykes inherited, by way of a mutual friend, copies of his predecessor’s notes and garden records, and like Foster, he bravely ventured into all sorts of deep and muddy waters with his experimental crosses between diploids and tetraploids and dwarf and tall species….
“Dykes traveled extensively to document species in the wild and collect them for horticultural evaluation; in his short breeding career, he introduced 34 cultivars, most in the early 1920s. Dykes died following a car accident in 1925. Two fitting tributes marked the next year: his wife, Katherine, introduced the yellow iris that bears his name, and in June 1926 the British Iris Society created the Dykes Medal honoring the most outstanding variety of the year — an award still coveted by breeders worldwide.”
Morning’s sudden and extravagant green seems to suggest the higher whiter waves of the air, what moves through the flurry of these first leaves, floating and falling beyond everything I am able to see.
Against that brightness, a flock of blue, a single yellow iris creaks on its shaft….
How persistently the eye resists the familiar, so easily finding itself content among its accustomed walls, the expected trees and avenues, that it fails to see them and will acknowledge only what has been changed or lost or taken away.
Hello!
This is the tenth of ten posts featuring photographs of irises that I took at Oakland Cemetery toward the end of April. The previous posts are:
In the ninth post in this series, I introduced a “self iris” whose standards and falls all demonstrated an intense, highly-saturated yellow color. As I described in that post, the ability of that iris to produce colors with such intensity originated in its genetic heritage (enhanced carotenoid production) as well as its growing environment (full day sunlight), which worked together to encourage the iris to produce more and more yellow-colored cells. In this post, we’ll look at some other yellow variations, so I’ve placed two representative samples to the right of the previous yellow self iris below to show their visual differences.
The irises like those in the second and third image above are located in older sections of Oakland Cemetery, neither kind receiving the same level of full-day sunlight as the first one. The partial sunlight they receive varies because they’re all located at boundaries between sun and shade, where nearby shrubs or trees filter out some sunlight at different times during the day. Both kinds get most of their sun exposure during the morning hours — something that irises like these are usually very happy about — with those like the second image spending most of their afternoons in full shade.
At the time I took the photographs — around mid-day — those like the second one were already fully shaded. That actually puzzled me a little, as I didn’t realize there were any irises that could do well with so little light, until I came across this brief note in Irises: A Gardener’s Encyclopedia by Claire Austin:
“In very hot climates, bearded irises will flower in shade. In Britain, the only bearded iris that managed to bloom in my garden in semi-shade was Iris flavescens, an old soft lemon variety.”
Though I couldn’t confirm it, I’d already concluded from my research on yellow irises that there was a good chance the shaded varieties were genetically related to Iris flavescens or its ancestors — because of their visual similarity to the yellows produced by William Rickatson Dykes and subsequent breeders. That such cultivars have been adapted to partial shade adds a bit of confirmation to that conclusion, especially since these shade-tolerant irises demonstrate another feature that enables them to adapt to lower levels of sunlight. Their falls — as you can see in the second image — don’t droop downward like the falls in the first and third images. Instead, they open to a horizontal or slightly upturned position and stay there while the flowers are in bloom. This enables them to capture additional sunlight (compared to the droopy falls), take advantage of fewer hours of sun shining on their petals, and still keep their photosynthesis humming along. Their ability to do so well with limited sunlight makes them ideal for their placement among the old memorial structures and stonework in the historical sections of the cemetery — where their heirloom quality fits perfectly with the garden design.
The final thirteen images below show different views of the blooms on a single iris plant, a very stately one positioned at the intersection of two walking paths in front of terraced walls, where it beckoned me to photograph it as well as its white and purple relatives in the background. This iris captures light midway between the well-sunned yellow self irises and the mostly-shaded heirloom irises, something that can be seen in its color production. The yellow saturation falls about midway between the other two cultivars; and its position in partial sun means that it doesn’t have to flood its petals with protective yellow carotenoids. It can, instead, retain and display one of its most significant features: carefully placed swatches of yellow near the throat of the falls, and similarly colored yellow striping edging those petals around an oval-shaped white foreground.
My camera, as it turns out, was somewhat mystified by this iris, and produced a RAW image that was mostly yellow — or at least appeared that way because there was enough yellow to create a color cast over the entire image. We end up with this color cast because there’s enough light (despite a cloudy sky) to over-saturate yellow and the color yellow fills so much of the frame in this close-up view.
A simple white balance adjustment — which removes yellow tint — gets us part way there; or, at least, starts to hint at the contrasting color combinations that are present in the falls. Now we can see that there’s pure white that was hidden by the camera’s interpretation.
This improved view of the colors in this iris’s falls influenced the adjustments I made next: I changed the color relationships to create greater separation between the flower’s yellow tones and its whites, then added some texture. The texture addition finishes the job, sharpening the contrast between yellow and white, and enhancing the fine vertical lines that run down the falls. Here are the three step changes showing the transition from the camera’s original interpretation, to the white balance adjustment, to the final version of this image.
Making these adjustments produces a cleaner and brighter image, but it also does something more important than that. It shows a flower that reflects the intentions of its breeders, who altered its genetics to produce the yellow and white contrasts, and the yellow edging, in the falls. The placement of this yellow edging reveals those intentions, because — as you can see in the final photograph — it’s so precise that it looks like it was drawn there, and appears not only on the tops of individual petals but is reflected or mirrored in the colors underneath the petals. Coloration like this is not likely an accident of nature for irises with decades of breeding history, so their photos should acknowledge the technological and scientific efforts, and examine that in the context of their use in formal or memorial gardens like those of Oakland Cemetery.
With that, we’ve come to the end of this project. Through ten posts, about 300 photographs, and around 10,000 words, we’ve done much more than just looked at pretty pictures of fine irises. We’ve traversed topics like how irises are classified scientifically and into color or pattern categories; how their appearance reveals their genetic history and breeding; and how they adapt to their environment by producing different colors and forms. We’ve positioned them across multiple cultural dimensions and explored how they fit into memorial or botanical gardens; how their presence relates to garden design; how photography, art, and poetry can help us see them better and learn more about them; and how they’ve been observed throughout history as symbols of life’s bounty, beauty, and endless complexity.
“I think we take yellow for granted in the iris world, despite the fact that clarifying it from sodden and sullied to lustrous and sparkling was one of the greatest challenges of iris breeding in the 20th century. Many have credited the venerable ‘W. R. Dykes’ (Dykes-Orpington 1926), the iris named for the godfather of the genus, with starting it all — stirring frenzy on both sides of the Atlantic for sun-kissed tints on iris flowers.
“The range of yellow could cover continents in geographical terms. From the palest butter and white blend like that of ‘Melted Butter’ (Fan 1994) to the eye-searing, dark cadmium yellow blossoms of ‘Throb’ (Weiler 1991), yellow unspecifically describes many colors.
“But for much of the iris’s existence, yellow was a rare color, save the few golden or dirty yellow examples of Iris variegata or I. pumila. The earliest yellow, and at that a pale naphthalene yellow, was probably ‘Flavescens’ (De Candolle 1813), an old-fashioned diploid still found along highways and around old homesteads. It seems that generations of gardeners have passed this variety around, or it’s seeded with vengeance beyond the confines of its planting space. Either way, it’s still a simple charmer worth having in stock should an ugly fence or shed need some herbaceous company.
“But early diploids like ‘Flavescens’ were limited in their ability to transcend their own murkiness and fulfill a breeder’s quest for shiny, lustrous yellow. The conversion of diploids to tetraploids made this jump effortless. The originator of the most important yellow of the 20th century, W. R. Dykes, earned the honor of having a clear yellow tetraploid seedling of his named posthumously after him. Though the parentage remains unknown and subject to speculation, there’s no arguing that almost every yellow tall bearded iris and many median irises trace back definitively to ‘W. R. Dykes’.”
It seems we took a little break after the eighth post in this series! It wasn’t really a planned break, but starting in the last week of June, we had the longest stretch of rain- and thunderstorm-free days that we’ve seen all spring. After April, May, and most of June made me feel like I’d put down roots in a rainforest, I finally got some consecutive dry days to work in my yard, clean up storm debris, discard plants that drowned in their pots, pull up weeds, and add a few plants for 2025 — including a couple of new daylilies (one called Cosmopolitan and one called Beyond Riches); two different kinds of canna lilies (one called Red Golden Flame and a pair called Bronze Scarlet); and some dark red Dipladenia, the shrubby cousin of the Mandevilla vine. Since my planting season got off to such a late start, I chose plants I know are good at handling the July through September Georgia heat. I’m sure I’ll photograph them all as they take root and start blooming, probably later this month or in early August. But for now, let’s get back to our Iridaceae….
The irises in this post and the next one will include several variations that show off many shades of yellow. As Kelly Norris suggests in the quotation at the top of this post, we may think of yellow irises as very common, perhaps ranking next to purple as one of the most common iris colors. Yet as we’ll explore in these last two posts: the yellow irises we see today have a complex natural and genetic history, where they’ve evolved from the pale yellows of their wild ancestors or early garden inhabitants to the richly colored and textured irises produced by modern breeders.
In one of my previous posts, I introduced a botanical drawing by 17th-century German artist Hans Simon Holtzbecker, who also created this drawing showing a purple and yellow pair side-by-side:
That Holtzbecker chose to pair these colors could be coincidental, or it could reflect his observation of purple and yellow irises found together in the European gardens he studied for his drawings. The right side of the drawing captures his interpretation of yellow shades that would have been prevalent among irises 400 years ago, showing the pale, dirty, or slightly golden tones Norris describes at the top of this post. Botanical drawings like this served a function that would later be provided by photography: documenting the forms and colors in the natural world, where artists like Holtzbecker produced accurate representations of the shapes and shades of specimens they studied.
When you look at Holtzbecker’s drawing, you’ll see where elements of the yellow iris that would receive less light — the throat of the flower, the bases of individual petals, or where the petals are curved — appear darker as the colors seem to shift from yellow toward orange. This is also true among my photographs, like this one…
… where Lightroom detects orange only in the flower’s beards, or in the most shaded sections behind each beard toward the center of the flower. The rest of the flower reads as yellow, whose tones we interpret differently based on the amount of light reflected by the petals. Had I photographed this flower in full sunlight, those subtle yellow tonal variations would not have been as evident. Light filtered through clouds not only reduces the amount of yellow coming from the sun itself, but also lets us see more of the color variations present in the flower. And yet: even filtered through the clouds, the saturated yellow in these irises was substantial enough to splash a yellow color cast across the entire image that was, thankfully, easy to correct by adjusting white balance.
I split my photographs of yellow irises between this post and the next one based on their location in the gardens. This post shows newer plantings that normally get full sun; the next one will include yellow irises from older sections where they receive partial sunlight at the edges of plantings like shrubs and trees, and are positioned among memorial structures placed in the cemetery decades ago. These location differences will help us see how environmental conditions affect an iris’s color, and connect us to the botanical history of and the chemistry behind an iris’s production of color.
The color consistency in these irises places them in the color category called “self irises” — where all the petals of both the standards and falls show one solid color. That consistency is evident even in the partially opened flowers (as shown in the first twelve gallery images below), and is different from the buds of irises like Iris pallida ‘variegata’ where — as I show in my fourth post in this series — the emerging flowers present the color variations they’ll contain at maturity. The intensity and saturation of yellow in these irises, however, tells us a lot about how they might have evolved from their paler ancestors.
The appearance of yellow in these irises is determined by their carotenoid production, the term “carotenoid” referring to the yellow, orange, and red pigments present in biological entities including flowers, fruits and vegetables, and happy creatures like canaries and flamingos. For our irises, though, carotenoids (think of the color of carrots as an easy memory trick) serve more than one purpose: they produce the yellow colors we find so appealing, they help the plant absorb sunlight for photosynthesis, and they protect the flower and the plant from getting sunburned by that same light.
Imagine, for a moment, that you spent your days standing in a rectangular garden at Oakland Cemetery, where you faced the sun all day long and had no access to any shade. You’d need epic amounts of sunscreen to keep from getting burnt to a crisp — something these yellow irises face during their entire blooming season. The irises, however, have their own coping mechanism: the intensity of the sunlight across their dense, compact cellular structure encourages them to produce more and more carotenoids in response, each increase in carotenoids providing an additional layer of protection while simultaneously ratcheting up the level of saturated yellow color we see in the blooming flowers.
The ability of our irises to do that is not accidental, and it’s unlikely that yellow irises like those Holtzbecker illustrated would have been able to survive or even tolerate intense, all-day sunlight. Irises of such saturated and protective yellow are distinctly modern: their development occurred in the twentieth century, enabled (as Norris states above) by “the conversion of diploids to tetraploids” — a chemically complex discovery through which geneticists doubled the amount of genetic material available in developing irises, enabling the creation of irises with greater color saturation and vigor. Newer cultivars like Throb from the early 1990s — an iris that’s very close in color saturation, appearance, and form to those I photographed — clearly demonstrate the results of these revolutionary efforts (originated by William Rickatson Dykes) to produce irises that were even more sun-tolerant than their predecessors.
