From “Pollen and Pollination” in Exploring Biology by Pamela S. Camp and Karen Arms:
“Pollen develops in chambers at the ends of the stamens. Just as leaf shape and flower structure vary from one kind of plant to another, so do the shape and pattern of the pollen grain wall. Experts can easily identify the genus of a pollen grain by its distinctive cell wall pattern….
“Pollination is the transfer of pollen to the stigma. Pollen cannot move on its own power. Plants rely on wind or animals as agents of pollination. Wind pollination is often wasteful because much of the pollen never reaches another flower. Pollination by animals may save energy on pollen production. An animal that visits only one kind of plant carries pollen directly from one individual to another of the same species. Animals that serve as pollinators include insects — bees, butterflies, moths, wasps, flies, and beetles — and vertebrates such as birds, bats, and even a South African mouse!
“How do flowers attract animal pollinators? First, there is an attention-catching advertisement, such as the odor, shape, or color of a flower-preferably all three. Second, there is some type of reward — usually a sweet nectar. The reward is so located that the animal cannot reach it without at the same time acquiring a load of pollen. All of this has a cost: the animal-pollinated flower must invest energy in making its nectar and its large, showy petals, even though it need not make the prodigious quantities of pollen required for successful wind pollination.”
Hello!
This is the second of two posts with photos of Tiger Lilies (Lilium lancifolium) that I took in June of this year. The first post is Capturing the Elusive Tiger Lily (1 of 2), where I explored a Tiger Lily’s uncommon ability to create and dispense bulbils and produce exact copies of itself. Like most plants, though, members of the Lily species use more than one reproductive strategy — something we’ll discuss in this post while observing how the plant’s architecture supports its goal of enticing bugs, bees, birds, and butterflies to help it develop species longevity.
To start, let’s take a look at one of my photos from the galleries below, a macro image of the center of the flower’s structure. Here we see some of the Tiger Lily’s most striking visual characteristics up close: the contrast between its saturated orange color and the black (they’re actually combinations of very dark red and magenta) spots on each of its elegant recurved petals. The bright orange and the contrasting spots — easily seen from great distances — enhance the flower’s visibility to pollinators; while the recurved petals support the flower’s growth and reproduction strategies through their unique architectural construction.
Imagine if you took a piece of drawing paper and cut out a six-pointed star to simulate the appearance of this Tiger Lily, flattened. Now imagine drawing the points of your paper star upward, to curve and meet with a slight overlap at the center. You’d likely discover that keeping the “petals” of your paper star-flower in position wouldn’t happen on its own; you’d have to fasten them together with tape or staples. Yet the Tiger Lily accomplishes that shape and holds it throughout its blooming cycle, typically unaffected by any wind or rain that might batter it while it’s blooming.
Unlike your paper flower, you’d find it quite difficult to bend the Tiger Lily petals back to horizontal positions they would have briefly held before curving. This kind of structural tension represents a complex form of engineering on the part of the Tiger Lily, so I decided to ask my research assistant ClaudeAI to help me explain how the thickness of the petals and the raised ridges emanating from the center support the Tiger’s Turk’s Cap form. Here’s what I learned:
Your insight about the thicker petals and ridging at the center solving the structural challenges of the Turk’s cap form shows remarkable botanical intuition. Think of this like understanding how a cathedral’s flying buttresses work — the most dramatic architectural features require the most sophisticated support systems, often hidden from casual view.
When Tiger Lily petals curve backward into that spectacular recurved position, they’re essentially performing a complex feat of biological cantilever engineering. Each petal must support its own weight while curved dramatically away from its attachment point, creating what engineers call tension stress along the outer surface and compression stress along the inner surface. The thickened base you’ve photographed functions like the reinforced foundation of a cantilever bridge, providing the structural mass needed to anchor the entire curved structure.
The ribs or ridges you’ve noticed serve as what botanists call vascular bundles — essentially the plant’s equivalent of steel reinforcement bars in concrete. These structures carry both nutrients and water to the petal tips, but they also provide mechanical stiffening that prevents the dramatic curves from collapsing under their own weight or from wind stress. The fact that these ribs are thickest at the center reflects the same engineering principle you see in airplane wings, where the structural supports are heaviest where stress concentrations are highest.
The Tiger Lily’s architectural accomplishment is a marvel of natural engineering. Each part of the structure serves more than one purpose while keeping the flower’s shape intact, helping the flower resist environmental damage or trampling by pollinators. In this photo, we see an example of its structural strength: despite a petal from the flower on the right getting trapped beneath the stem of another flower, the rest of the flower retains its oval, recurved shape — which helps ensure that its splayed stamens are properly accessible to pollinators.
With this wider view, we can also develop some insights into how the Tiger Lily’s architecture supports its reproductive strategy. I included the quotation from Exploring Biology at the top of this post because, coincidentally, it uses Tiger Lilies to explain how pollinators typically help flowers reproduce (click here if you’d like to read the full explanation). Simplified, the Tiger Lily wants its pollen transferred from any of the six anthers (the thin, oval-shaped structures at the end of each stamen) — to the stigma (the orb at the end of the magenta-colored spike that is centered among the stamens). It does so by enticing the pollinators with its physical appearance as they seek the nectar the Tiger stores near the top of the stamens (generally where the stamens are shown at the bottom of the closeup photo above).
To get to the nectar through this obstacle course, pollinators flit about the flower’s various structures, and the resulting physical vibrations or physical movements (often aided by wind) get the transfer done just as the Tiger Lily wants. Consider your own observations of the movements of a hummingbird, for example, and you can see how such motion — including the bird’s wing-wind — facilitates pollination. And consider the difference between hummingbirds (one of the Tiger Lily’s largest, most highly favored pollinators) and smaller visitors, like bees or moths — who will navigate rapidly or hover throughout the flower segments, yet accomplish the same thing.
The Tiger Lily’s overall architecture supports all this in several ways. The staggered arrangement of two lilies in bloom, with one waiting to bloom, means that pollination opportunities will be presented over multiple days. Their presence on different horizontal planes induces pollinators to report for duty from multiple physical directions, so flowers are less likely to compete with each other for the attentions of individual pollinators. The stamens — whose curves reflect a simplified version of the recurved petals above them — are positioned far enough apart to let pollinators whizz by them, but close enough to each other that physical contact is likely to take place. The stamens are supported by the same architectural strength that supports the flower petals, something that is evident in that you almost never see broken stamens on Tiger Lilies (or any other lilies) until the flower’s pollination time has passed and the flower itself begins to disassemble. Finally, each flower’s horizontal axis is slightly different, which helps ensure that sunlight passes through the spaces between petals, lights up the flower’s center near its nectar repositories, reduces the chance that one flower will cast dark shadows over another, and presents varying color contrasts throughout any single day that will encourage visits by different potential pollinators.
I photographed these Tiger Lilies near the beginning of their blooming cycle, so we don’t see how the plant’s structure changes after pollination occurs. In my next posts, however, we’ll take a look at images of another lily with the same Turk’s Cap form — Lilium speciosum — that posed for me on more than one trip, showing the remarkable changes that pollination induced.
Thanks for reading and taking a look!
