Pink Lady's Slipper (Cypripedium acaule)

Pink Lady’s Slipper (Cypripedium acaule, Orchidaceae)>

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Lady’s slipper orchids have a commanding presence—their  inflated blooms are captivating to the point of heady swooning and inspiring colorful prose. The etymological root of the word orchid comes from the Greek orchis, meaning testicle. Certain species of orchid bear roots, which resemble paired testes. In pink lady’s slipper, it is the flower, and not the root, that is reminiscent of naughty bits. Orchids typically have three petals, with one of the flower’s petals forming a pouch-like structure, aptly named the labellum. The Latin root of labellum, is little lip, or labia. In pink lady’s slipper the labellum is inflated and heavily veined. The other two petals are pink and narrow, twisting, and extending out to the side of the flower, like a dancer’s arms in mid-twirl.

The enticing pink petals, along with the flower’s wafting fragrance, attract large bumblebees, who clumsily pry their way into the inner chambers of the labellum through the slit down the front. Once inside, the bees quickly realize they have been duped, as there is no nectar to be found. The bees are unable to retreat via the labellum due to the petal’s crafty design, so they look elsewhere for an escape from the pink luminescent chamber.

Close-up of a pink lady’s slipper flower’s labellum

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Let’s pause this sordid pollination tale for a moment, and perhaps project a bit onto the bee’s reality (never miss an opportunity to interpret life through an insect’s perspective). Do the trapped insects take a moment to reflect? Perhaps some bees, being of a naturally philosophical persuasion, might feel something like this: “Well, I took a wrong turn, but the color and the light in this silent cloister is so soothing and peaceful, perchance a nap is in order.” Or maybe the high-strung bee, traumatized by past encounters with nectarless flowers, begins to feel claustrophobic, maybe even a little sheepish, and becomes disoriented in their desperation to find freedom. Five of the panicked bee’s legs become ensnared in the labellum and the bee perishes alone.

But wait, let’s not let our daydream end in slow death sadness—our lady’s slipper is no insectivore; it eats dirt, not hapless bees! The totally buzzed out bee takes a deep breath and looks around. Light, up above! Freedom calls, and our bee gingerly pulls their legs free, one at a time, and flies upward and onward. They bang their head against something as they makes their exit, but eventually they wriggle free and go on to find a blueberry bush sporting ample flowers. All of which bear nectar, and are straightforward with their simple single opening.

When the bee exits the flower, they bump their head against the reproductive parts of the orchid, which are joined into a central bisexual reproductive organ, named the column. As the bee brushes against the lady’s slipper private parts, they pick up a mass of pollen. Now, most flowers produce thousands of pollen grains, all tiny separate structures, which our eyes perceive as gold dust. There’s enough to go around for all the pollinators, or for the breeze to pick up and transport to other flowers. But orchids have a different strategy—they put all their eggs into one basket, so to speak. All of their pollen grains are massed with waxy glue into one large pollen glob, which is called a pollinium. It’s a one shot deal. Which is perfect for a flower that doesn’t actually deliver. How many times will a single bee be duped? Eventually, the bee will wise up and realize those beautiful large lips are lying.

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The narrow slit in the front of the labellum where pollinators enter, but do leave from

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There is a reason that most flowers reward pollinators with nectar and/or pollen—it keeps them coming back. Only about 5% of lady’s slipper flowers are pollinated in a given year. Douglas Gill, of the University of Maryland, conducted a study on a population of pink lady’s slipper. He found that when the trees growing above the lady’s slipper were destroyed by gypsy moths, the orchids flourished. Flowering increased six-fold and the average successful pollination rate increased from 2.6% to 20.7%. Gill theorized that lady’s slipper increased visitation by bumblebees was due to the greater sunshine and openness and also proximity to heath family members, such as blueberry. He goes on to surmise that fire plays a role in the success of lady’s slipper pollination by periodically opening up the forest floor to more sunshine, and thus more pollinators. Fire suppression may be yet another stressor for this rare charismatic orchid.

Let’s return to our bee, who is presently satiated with blueberry flower nectar and resting on a cushiony clump of moss warmed by the dappled soft sunlight of the late afternoon. As they doze off into bee dreamland, they spy another lady’s slipper, and shudders with the recent memory of their temporary entrapment. But there’s a part of them, the one who is always searching for the fabled fountain of nectar, who whispers in their own ear, “That flower is so large, so succulent, surely there’s a treasure of nectar, a golden pool of sugar at the base of the flower.” Maybe the bee imagines slipping their mouthpart into a deep well of sweetness and drinking until they are so full they are unable fly home. The bee knows they shouldn’t, danger lurks, but they must.

Compelled, they enters the second lady’s slipper, more tentatively this time, and their heart drops when they behold the dry inner chamber. This time she will not allow herself to be flustered. She heads straight up towards the exit, and oeuff, there’s that danged thing they banged their head on last time. As the bee slips out the rim of the flower, the pollinium slips off their back, and lands squarely on the stigma of the flower.  Mission accomplished: pollen from our first lady’s slipper flower was delivered directly to the stigma of our second flower. The bee never looks back.

Now pollination takes place, then fertilization, and finally, thousands of minute orchid seeds are produced in a brown hard pod. The tiny seeds are so small that they can take a ride on the wind, but their size comes with a price. Most seeds have just enough reserves to see them through until they are able to photosynthesize and make their own way in this wide wild world. Not orchid seeds. Smaller than a grain of salt, in the beginning they are at the mercy of fungi for everything. When the seed meets up with a tentative strand of mycelium (fungal body) they join in inter-species rapture (alright, perhaps more conjecture and anthropomorphizing, but it’s so fun to pretend!). The fungi helps the seed to germinate, and nurtures it along, as they begin a lifelong love affair, or symbiosis.

It can take three years from germination until the lady’s slipper seedling even makes its first green appearance above ground. And then another three to five years before its big enough to flower. Once a lady’s slipper is established, it lives for an average of two to three decades, flowering every few years or so. Some authors claim that the plants can live for over a century, and possess the ability to remain subterranean for years, even up to a decade, when conditions are adverse. Lady’s slipper may engage in some serious floral shenanigans, but it does eventually repay its debt to its early fungal benefactor by sharing some of the sugars it produces through photosynthesis.

Cypripedium acaule, Orchidaceae

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One might imagine, with this slow growing lifestyle and deceitful germination strategy, that lady’s slippers are not that abundant. And one would be right. Lady’s slipper root was once a popular medicine, overharvested for its use as a nervine, relaxant and aphrodisiac. By the time I came of herbal age in the late eighties, most herbalists had already stopped using lady’s slipper due to its scarcity. I imagine the harvesting of lady’s slipper for medicine to be as shameful as killing a rhinoceros for its medicinal horn, or a black bear for its gall bladder. Maybe even as dastardly as slaying a unicorn to use its horn in flying medicine.

Although lady’s slipper is no longer harvested for medicine, it faces other threats in the form of habitat loss and poaching. The plants are often dug up and either sold or replanted. Most plants do not take well to transplanting, perishing or languishing, as the fungal/root connection is disturbed. Please never pick lady’s slipper for medicine, and never attempt to dig it up and transplant it.

Pink lady’s slipper’s scientific name is Cypripedium acaule; the species name means stemless, which is somewhat confusing as the flower actually has a stem. But the flower stem is not technically a stem—it’s a flower stalk, which botanists call a scape. Cypripedium acaule can easily be differentiated from other lady slipper species because its flower stem has no leaves. Pink lady’s slipper grows in dry or wet acidic woods, under conifers such as pine and hemlock, or in mixed hardwoods. In the southern Appalachians, I see it growing under sourwood, white pine and tupelo trees. Its range extends from Newfoundland, west to Alberta, down into northern Alabama and eastern Georgia.

I spend a lot of time romping through the woods, and pink lady’s slipper is as uncommon as ginseng in southern forests. Some years there are few flowers; this year the elements have been kind and many lady’s slippers are flowering. These photos are from a patch I have been visiting for a decade. The plants are close to a road and a well-traveled trail, yet people have let them be. I have seen no sign of harvesting or digging. The only people I see near the patch are wildflower enthusiasts making their annual pilgrimage to pay homage to this rare beauty. It gives me hope for the humans, and hope for the future of lady’s slipper.