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Lady’s Slippers: Once a Commercial Conundrum, Now a Conservation Success Story


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IT WAS JUNE 1980, MY FIRST YEAR IN THE OZARKS, and I was beginning to make friends with Arkansas botanists. One botanical friend I accompanied on searches for rare plants was Richard H. Davis (1946–1983), a field ecologist for The Nature Conservancy under contract with the Arkansas Natural Heritage Commission. He was particularly interested in rediscovering rare plants in historical locations recorded on herbarium specimens, but not seen in their native habitats for decades.

On one exhilarating hike, we rediscovered the location of the rare Ozark-endemic yellow coneflower (Echinacea paradoxa var. paradoxa, Asteraceae), which is the only Echinacea species with yellow flowers instead of the usual purple. Another excursion took us to a historical location for the most southwestern known population of showy lady’s slipper (Cypripedium reginae, Orchidaceae), known in older works as C. spectabile. This lady’s slipper is both a “queen” and a “spectacle,” as the species names imply. It is the largest and perhaps the most impressive native North American orchid and grows up to three feet tall with gorgeous three-inch-wide flowers that are whitish to translucent red on the pinkish side. It is Minnesota’s state flower.

We were looking for it at the edge of the plant’s southern range. We hiked up a circuitous creek bed in the water because the terrain was too rugged to do otherwise. We reached the historical location and searched forests and bluff faces high and low, spending the better part of a day, and I had a face-to-face encounter with a coiled cottonmouth (a rare genetic subspecies endemic to that watershed) ready for me to make the wrong move. We left each other alone. Disappointed by our failure to find the elusive orchid, we headed back downstream. Then, much to our surprise, there it was, about 10 feet up on a narrow limestone shelf: the showy lady’s slipper in full bloom.

In the search for rare plants, such moments evoke ecstasy. It is like meeting an old friend, or a celebrity in person. The beauty of lady’s slippers enamors humans — sometimes too much. Their beauty invites some to pluck them from the wild to embellish a vase or enhance a garden, while others harvest the roots for traditional herbal medicine uses.

In a series of articles published in 1913 in the Journal of the New York Botanical Garden, Elizabeth G. Britton warned that the “pink moccasin flower” (C. acaule), formerly found in wilder parts of the greater New York area and Staten Island, “is becoming extinct, on account of its showy flowers, which are usually plucked close to the root.”1

In southern Maine, many people are familiar with pink moccasin flower, also known as pink lady’s slipper. A child picking a pink lady’s slipper flower as a gift for their mother, instead of receiving delighted gratitude, may be roundly scolded for the affront to nature and warned not to pick lady’s slipper flowers. “It’s illegal!” a mom might exclaim. Of course, it is not illegal except where designated on public or private land, but recent generations of Americans grew up with an ethos against picking lady’s slippers. They are too rare, too special to disturb.

The Genus Cypripedium

Currently, 52 species belong to the genus Cypripedium. Twelve species and three subspecies are native to the United States and Canada; three species occur in Mexico and Central America; one is from Europe; and 36 species are found in China, 25 of which are found only in China.2 Except for the bold, yellow-flowered Kentucky lady’s slipper (C. kentuckiense), named in 1981, eastern North American species were known to Europeans soon after their arrival and described by botanists in the mid-to-late 18th century, with some recorded as early as the 1630s. Botanists described six western North American species by the mid-19th century. Cypripedium combines two Greek words, one honoring Cyprus, the supposed birthplace of the mythical Aphrodite (Venus), and pedium, meaning “foot” or “slipper” (Aphrodite’s slipper), alluding to the inflated shape of the flower lip.

European Yellow Lady’s Slipper

The single northern European species of lady’s slipper, the European yellow lady’s slipper (C. calceolus), is considered by some to be the poster child, the flagship species, of plant conservation in Eurasia. One of Europe’s most-studied plants from a conservation biology perspective, it has a broad range that includes most of Europe (including Crimea and the Mediterranean region), Asia Minor, and western and eastern Siberia, stretching to the eastern edge of Russia. Recently discovered in the Djurdjura mountain range in north-central Algeria, its known range, for the first time, now extends to North Africa.3

Now, the climate crisis is expected to impact the plant’s future. Under some climate change scenarios, the European yellow lady’s slipper could lose up to 63% of its habitat by 2070, and up to 24 of its pollinators could lose suitable ecological niches during that time.4 Much more widespread in the 19th century, it declined due to over-collection for horticulture, along with habitat loss.

England’s Poster Child for Plant Conservation for Four Centuries

For 400 years, the primary threat to the European yellow lady’s slipper has been the desire to sell it at horticultural markets or transplant it into gardens. Botanical and herbal authors from the end of the Renaissance in the 16th century to the early years of the Age of Enlightenment in the 17th century, including leading English herbal authors, commented on the occurrence and decline of the European yellow lady’s slipper.

English herbalist John Gerard (1545–1612) admitted in his 1597 Herball or Generall Historie of Plantes that he grew wild-dug lady’s slippers in his garden: “Ladies slipper groweth upon the mountaines of Germanie, Hungarie, and Poland. I have a plant thereof in my garden, which I received from Master Garret Apothecarie my very good friend.”5

Gerard recorded that the European yellow lady’s slipper, although a curiosity as a garden plant, found no use in British herbal practice. In Herball, he wrote: “Of our Ladies Slipper or our Ladies Shooe, touching the faculties of our Ladies shoo, wee have nothing to write, being not sufficiently known to the older writers, no not to the new.”5

In his 1629 Paradisi in Sole Paradisus Terrestris (“Park in Sun’s Terrestrial Paradise”), English herbalist John Parkinson (1567–1650), apothecary to King James I of England and royal botanist to King Charles I, recorded:

It groweth likewise in Lancashire, neare upon the border of Yorkeshire, in a wood or piece called the Helkes [Helks Wood], which is three miles from Ingleborough, the highest hill in England, and not farre from Ingleton, as I am informed by a courteous Gentlewoman, a great lover of these delights, Mistris Thomasin Tunstall, who dwelleth at Bull-banke, neare Hornby Castle in those parts, and who hath often sent mee up the rootes to London, which have borne faire flowers in my Garden.6

Of “the vertues” of the plant’s roots, Parkinson wrote: “There is no use of these in Physicke in our dayes that I know.”6

Other orchids are included in the writings of classical authors such as Greek botanist and “Father of Botany” Theophrastus (ca. 371–287 BCE) and Greek botanist Pedanius Dioscorides (ca. 40–90 CE), though the identities of the plants are questioned and confused with false hellebores (Veratrum spp., Melanthiaceae), which have similarly pleated leaves, yet are toxic to ingest. A 1552 edition of French physician Jean Ruel’s Medicinali Materia, a translation of Dioscorides’s De materia medica, includes the first known illustration of the yellow lady’s slipper orchid.8

In volume four of his six-volume 1777 Flora Londinensis, English apothecary-turned-botanist William Curtis (1746–1799) described conservation concerns related to yellow lady’s slipper:

The beauty and extreme singularity of the blossoms of the plant, joined to its great scarcity, have occasioned it to be universally sought after by botanists and others; who, not content with contemplating its beauties in its native soil, are anxious to see it grow in their gardens, in which, however, they are generally disappointed, as it very rarely thrives on transplanting. We saw, indeed, a few instances to the contrary in some gardens in Yorkshire. To this rage for the Ladies Slipper we may attribute its present scarcity in Helk’s Wood near Ingleton, where it used to be found in plenty. We were fortunate enough to discover this plant in considerable plenty in the neighbourhood of Kilnsay, not only in the Woods with its usual attendant, the red-flowered Helleborine [Cephalanthera rubra, Orchidaceae], but also in hilly pasture ground, with the Ophrys ovata [Neottia ovata, Orchidaceae]; but as some gardeners in the neighbourhood had discovered them, and were unremittingly employed in digging up every one they found, we may venture to prophecy; that in a few years they will be rarely found here also.9

Ten years later, Curtis’ prediction appeared true. English botanist and physician William Withering (1741–1799), famous for introducing foxglove (Digitalis purpurea, Plantaginaceae) leaves as a cardiac drug, writes in volume 2 of the second edition of his A Botanical Arrangement of British Plants: “I searched for it in vain in Helk’s Wood, a gardener of Ingleton having eradicated every plant for sale.”10

Withering also challenged gardeners to propagate the plant from seed, which was a technically impossible task before new propagation methods were developed in the late 20th century: “The gardeners might make botanists amends, at the same time that they would enrich themselves, by proving by experiment that one at least of the Orchis tribe may be raised from seed.” He closed with: “Goats eat it.”10

Despite their seductive lure, terrestrial orchids are notoriously challenging to propagate, grow, and coax to thrive. The challenges start with the plants’ complex reproductive biology. English naturalist and biologist Charles Darwin was fascinated with orchid pollination systems, which engage complex and deceptive signals to lure pollinators. He is one of the major contributors to modern understanding of orchid pollination biology and wrote a book on the subject, Fertilisation of Orchids, which was published in 1862.11

Orchid seeds are like dust, nearly microscopic. A single orchid fruit may hold tens of thousands or hundreds of thousands of seeds. Because of their tiny size, the seeds contain very little nutrient reserves. Therefore, they germinate only in association with compatible mycorrhizal associations (symbiotic associations between plants and fungi), both at the germination stage and until seedlings develop.12 The reproducing plant tissue adheres to mycorrhiza beneath the soil surface for several years before leaves appear above ground.

The obligate relationship between lady’s slippers’ seeds and soil fungi is essential to the orchids’ survival and was observed as early as 1824 by German botanist Johann Heinrich Friedrich Link (1767–1851), director of the Botanical Garden and Botanical Museum in Berlin from 1815 until his death in 1851. Results were first published in his Elementa Philosophiae Botanicae.13 In later works, he produced detailed drawings of mycorrhiza with germinating seeds and seedlings of a tropical orchid. The tiny seedlings of many terrestrial orchids are simply a small mass of white tissue below ground, tended by the mycorrhizal filaments that supply water, minerals, and carbohydrates until finally, after several years, the seedling produces above-ground leaves and becomes self-sufficient through photosynthesis.14,15

Before conservationists raised the alarm to save the plant from extinction in England, the country’s wild yellow lady’s slipper population declined to a single plant in the Yorkshire Dales by the 1930s. By 2010, this specimen had 24-hour police protection. Through the efforts of a tissue culture lab at the Royal Botanic Gardens, Kew, the plant has been re-established at 11 sites in its former range, and two of the sites are accessible to the public for chaperoned viewing.16

In the Netherlands, a conservation effort including landowners, environmental groups, local authorities, scientists, and media resulted in the mass propagation and marketing of the European yellow lady’s slipper.17 The species is making a still-tenuous comeback.

Eastern North American Lady’s Slippers

The major focus of this article is the historical use and conservation of the six Cypripedium species in eastern North America. At least two of the six western North American species are recorded as used by native groups. Mountain lady’s slipper (C. montanum) is a western North American species found in northern Wyoming, Montana, northern California, Oregon, Washington, adjacent Canada, north to Alaska. Its leaves were used by the Okanagan-Colville to aid pregnant women in birthing small babies.18 The rare species sparrow’s-egg lady’s slipper (C. passerinum), found from Quebec to Alaska, south to Montana, was used as a love charm, in which a single strand of a woman’s hair was tied to a stem and kept next to a man’s heart.19 Neither seem to be involved in the historical American commercial botanical trade.

Understanding the conservation, plant biology, and reproduction of the European C. calceolus is important for getting to know North American yellow lady’s slippers. In fact, the North American yellow lady’s slippers were once considered a variety of the European species: C. calceolus var. pubescens. American taxonomic botanist Donovan Stewart Correll (1908–1983) considered all North American yellow lady’s slippers to be highly variable varieties of C. calceolus, which he believed to be a circumboreal species occurring in northern temperate regions of Europe, Asia, and North America. “I am led to the conclusion,” he wrote in 1938, “that Cypripedium calceolus L. is a polymorphic boreal species to which our North American yellow Cypripediums should be referred…. At best, our plants should be given only a varietal position in which polymorphism [clearly distinct forms or phenotypes occupying the same population] should be recognized as a constant tendency…. I further conclude that future attempts to segregate our yellow Cypripediums into [anything] other than the comprehensive var. pubescens category should be left to the geneticists. It is apparently not a problem for taxonomists!”20

According to Sheviak’s treatment in volume 26 of the Flora of North America, North American yellow lady’s slippers are divided into two species: C. parviflorum and C. kentuckiense. Cypripedium parviflorum has three varieties: (1) C. parviflorum var. makasin, the northern small yellow lady’s slipper, which occurs from Newfoundland to Alaska, south to Iowa and northern California; (2) C. parviflorum var. pubescens (syn. C. hirsutum), the large yellow lady’s slipper, which has a range similar to var. makasin, though extending further south to the Southern Appalachians, Ozarks, and through higher elevations of the Rocky Mountains; and (3) C. parviflorum var. parviflorum, the southern small yellow lady’s slipper, which occurs from southern New Hampshire through the western mountains of the Carolinas and in northern Georgia west to the Ozarks of Arkansas and Missouri.21 These varieties are extremely variable, with plasticity (the ability of organisms to change phenotypes in response to the environment) and hybridization with other species resulting in different delineations of geographical ranges and identification features in various descriptive botanical works.

The second eastern North American yellow lady’s slipper species is the distinctive Kentucky lady’s slipper (C. kentuckiense), which has yellow-to-ivory flowers and is also known as the ivory lady-slipper or purloined slipper. It occurs from Virginia to Georgia, west to Texas and eastern Oklahoma. Almost half of its 150+ known populations are found in Arkansas. It was first named in 1981.21

The most common and easily recognizable slipper orchid species in eastern North America is the pink lady’s slipper, C. acaule (syn. C. humile). “Acaule” means stemless, referring to the pair of opposite stemless leaves at the base of the plant. The pink (sometimes white) flowers, which bloom from about April to July, occur in a wide range of forests from Newfoundland, south to the mountains of northern Georgia and Alabama, and northwestward to northeastern Alberta.21

Richard Primack, PhD, a professor of biology at Boston University, investigated the reproductive biology, phenology (the study of the relations between climate and periodic biological events), and dynamics of pink lady’s slipper populations for more than a decade. According to Primack, the perception of rarity of pink lady’s slipper stems from conservation efforts in the early 20th century that attempted to get gardeners to stop taking the plants. By the late 20th century, a tremendous increase in their numbers was recorded in New England, as former agricultural land reverted to its former state of woodland habitat.14

The showy lady’s slipper or Queen’s lady slipper, C. reginae (formerly C. spectabile and C. canadense), which flowers from about May to August, has a broad range from Labrador, south to western North Carolina, west to Arkansas, and northwest to southeastern Saskatchewan. It is among the most spectacular wildflowers.21

White lady’s slipper (C. candidum) blooms from about April to July, emerging while the leaves are unfurling at the base of the plant. It ranges from New York, south to the mountains of northeastern Alabama, northwest to Nebraska, and north to Manitoba. It sometimes hybridizes with yellow lady’s slipper.21

Finally, one of the rarest of the eastern North American species, C. arietinum, the ram’s-head lady’s slipper, is a small flower, mostly found in coniferous or mixed forests and glens from Nova Scotia, southwest to New York, northwest to Minnesota and Saskatchewan.21

What do these species have in common? At one time or another, all six of the eastern North American species and three previously described varieties were involved in the historical trade of lady’s slipper root as a medicinal herb.

Lady’s Slippers in North American Herbal Traditions (1822–1926)

Thomsonian Nerve Powder

Samuel Thomson (1769–1843), purveyor of the populist-driven Thomsonian system of medicine, included three species of lady’s slipper (C. parviflorum var. pubescens, C. acaule, and C. reginae) in the first edition of his New Guide to Health; or Botanic Family Physician published in Boston in 1822. He called it “nerve powder” or “American valerian,” of which he wrote: “The powder [of the root/rhizome] is the best nervine known; I have made great use of it, and have always found it to produce the most beneficial effects, in all cases of nervous affection, and in hysterical symptoms [broadly related to uterine conditions]; in fact it would be difficult to get along with my practice in many cases without this important article.”22 The Thomsonian system of medicine, which thrived from the 1820s until Thomson’s death in 1843, seems to have first promoted lady’s slippers’ commercial use. Before Thomson’s adoption of the herb, it was considered a domestic remedy, whose use likely was learned from Native Americans.

A one-time partner and later competitor of Thomson, Morris Mattson (1808–1885) published his The American Vegetable Practice in two volumes in 1841. Thomson and Mattson planned to co-author the work, but a falling-out left Mattson to produce it himself. Mattson included the roots of four species (C. acaule, C. parviflorum, C. candidum, and C. reginae) in his entry for lady’s slippers. “The roots of these plants are nearly similar in virtues,” he wrote. “Those of the purple [C. acaule] and the yellow lady’s slipper [C. parviflorum], however are the most active and efficient.” A second edition appeared in 1845. Of pink, or “purple,” lady’s slipper he wrote: “It is tolerably frequent in some parts of Massachusetts. Maine also yields it abundantly. It was formerly very plenty in the woods of New Jersey, but in an excursion there, about two years ago, I found that it had almost entirely disappeared.”23

C.S. Rafinesque Claims Discovery and Introduction

Constantine Samuel Rafinesque (1783–1840) in Medical Flora; or, Manual of the Medical Botany of the United States of North America (vol. 1, 1828), claimed to first promote the properties of lady’s slippers to the medical community:

It is with some satisfaction that I am enable to introduce, for the first time, this beautiful genus into our Materia Medica: all the species are equally medical; they have long been known to the Indians, who called them Mocasin flower, and were used by the Empirics of New England, particularly Samuel Thompson [sic]…. The most efficient is the C. luteum, next C. acaule, and last C. spectabile [C. reginae] and C. candidum.24

Rafinesque, quick to apply new taxonomic nomenclature that was often rejected by his peers, combined all the yellow-flowered lady’s slippers into his new species “Cypripedium luteum,” then further classified his observed variations into eight varieties of yellow lady’s slippers. Other botanists never accepted Rafinesque’s confusing taxonomic treatment of yellow lady’s slippers.

Describing their properties, Rafinesque wrote:

They are sedative, nervine, antispasmodic, &c. and the best American substitute for Valerian [Valeriana officinalis, Valerianaceae] in almost all cases. They produce beneficial effects in all nervous diseases and hysterical affections, by allaying pain, quieting the nerves, and promoting sleep. They are also used in hemicrania [a headache on one side of the head], epilepsy, tremors, nervous fevers, &c. They are preferable to Opium in many cases, having no baneful nor narcotic effects. The dose is a tea spoonful of the powder, diluted in sugar water, or any other convenient form. As in Valerian, the nervine power is increased by combination with mild tonics. The powder alone has been used; but an extract might be also efficient unless the active principle is very volatile.24

He and others preferred the yellow lady’s slippers, but one of the most important observations from Rafinesque’s writings was that depending on one’s location, any Cypripedium species would do. As a result, in 19th-century North America, and well into the 20th century, tons of dried lady’s slipper roots entered the herb trade, offered as “American valerian,” or lady’s slipper root, “mocassin flower,” “nerve-powder,” “nerve-root,” and “squaw-root,” among other common and trade names.

Skeptical Reception by Allopathic Physicians

Some physicians, such as Ohio’s John Milton Bigelow, MD (1804–1878), were skeptical about the reported efficacy of lady’s slippers. “Roots, employed by Indians and Steam doctors [a derogatory stab at the Thomsonians], under the name of nervine, as a sedative and anti-spasmodic, in hysteria chorea [historical term for nervous conditions involving twitching movements], and kindred diseases. Supposed to act like Valerian. I have, however, seen it administered frequently, but could never detect the slightest appreciable effect whatever,” he wrote.25

In an 1849 essay on the medical botany of Massachusetts published in the second volume of the Transactions of the American Medical Association, Stephen W. Williams, MD (1790–1855), also expressed skepticism, reflecting professional prejudice based on the well-documented schism between conventionally trained physicians and their alternative botanical counterparts of the mid-19th-century United States. He wrote:

This plant is much in vogue with the quacks and steamers. They say it possesses properties equal, if not superior, to foreign valerian. They dry the root and powder it fine, and keep it in tight stopped bottles. They call it nervine, and use it in nervous affections. They also employ it to assist the operation of their emetics, in doses of half a teaspoonful. It is said to quiet the nerves, prevent spasm, and produce sleep without stupefying. When a person cannot sleep, they put a teaspoonful of this powder into a teacupful of pennyroyal tea, and drink it warm on going to bed at night, and they say it will produce quiet and refreshing sleep. The root is the only part used. The roots are pungent and mucilaginous.26

Embraced by Eclectic Physicians

Lady’s slipper roots and their preparations were adopted by the Eclectics, a group of physicians who largely relied on preparations of North American medicinal plants and whose practice thrived from the 1850s until their demise in the 1930s. The practice was resurrected and esteemed by modern medical herbalists, however, and Eclectic physicians were recognized for their contributions to what later became European phytomedicine. In the 1854 second edition of The American Eclectic Dispensatory by John King, MD (1813–1893), the author included yellow lady’s slipper under his main entry for Cypripedium pubescens, including C. parviflorum, and provided evidence that other species were used as well: “There are several varieties [species] of it, all of which are undoubtedly collected, sold, and used, with the officinal article indiscriminately.”27

He lists the species now known as C. reginae, C. acaule, C. candidum, and C. arietinum as source plants of the lady’s slipper roots in commerce, perhaps mirroring Rafinesque’s earlier work. Lady’s slippers became a standard drug used by Eclectic physicians and were detailed in Eclectic materia medica and dispensatories well into the 20th century. In 1922, Eclectic physician Harvey Wickes Felter (1865–1927) wrote: “Cypripedium is an ideal tranquilizer for states of nervous excitability or irritability depending upon atony. It dispels gloom, induces a calm and cheerfull state of mind, and by thus inducing mental tranquility favors restful sleep.”28

“Specific Medicine Cypripedium” was sold by Lloyd Brothers, Pharmacists, Inc., in Cincinnati, Ohio, the primary suppliers of drugs dispensed by prescription only by Eclectic physicians. Respected pharmacist and author John Uri Lloyd (1849–1936) in History of the Vegetable Drugs of the Pharmacopeia of the United States provided perspective on the widespread use of Cypripedium. According to Lloyd:

It has been valued as a domestic remedy and was once a home favorite in the form of a decoction for nervous conditions of women and children. It was thus utilized by early settlers as a substitute for valerian, which fact gave it the name ‘American valerian.’ Creeping thus into domestic therapeutic use, it naturally received the care and attention of the ‘Indian doctors’ and came gradually to the attention of the medical profession. To give the references necessary to its American record would cite all the domestic writers on American medicine of the 19th century, as well as such authorities as King, Wood, and Bache,* etc.29

Relative Latecomer to the United States Pharmacopeia

Relatively late, lady’s slipper was adopted in the primary list of drugs in the United States Pharmacopeia (USP) in the 4th and 5th revisions (1860, 1870), then was relegated to the secondary list in the 6th to 8th USP revisions (1880, 1890, 1900), and dropped from the USP 9th revision (1910). It was subsequently included in the National Formulary IV-V (1916, 1926).30

In a survey, “vegetable drugs employed by American Physicians,” which was mailed to 30,000 practicing physicians and published in 1912, John Uri Lloyd reports that of more than 10,000 respondents, Cypripedium (as listed in the 1900 USP) was 23rd among the 36 most widely prescribed plant medicines, with 2,062 physicians reporting they prescribed it.31

Demand Outstrips Supply

Once lady’s slipper moved from being a local domestic remedy to a commercial botanical, pharmacies and wholesale drug suppliers in northern cities and the Midwest turned to bulk suppliers to meet demand. A major source included the herb departments of the Shaker communities in New Lebanon, New York; Harvard, Massachusetts; and Canterbury, New Hampshire, among other Shaker communities that were active in the medicinal plant wholesale trade of pulverized or dried whole root, fluid extracts, and tinctures. They offered products under their own labels and provided contract manufacturing services for other vendors. The New York Shakers’ competitor, Tilden & Co. in New Lebanon, was also a major lady’s slipper product supplier. In incomplete account summaries, the Mount Lebanon Shakers recorded the processing of 2,016 pounds of pulverized lady’s slipper root (species not specified) from 1856 to 1876. Lady’s slipper products were dispensed by Thomsonian physicians, the emerging Eclectic medical movement, as well as by conventional medical doctors.

According to Luke Manget, PhD, in his wide-ranging 2017 dissertation “Root Diggers and Herb Gatherers: The Rise and Decline of the Botanical Drug Trade in Southern Appalachia,” the Shakers and Tilden & Co. bought dried raw material from Calvin J. Cowles, a merchant from Wilkes County, North Carolina. Manget credits Cowles with initiating the wholesale wild-collected herb trade from southern Appalachia to fulfill the growing demand for raw material from cities in the Northeast and Midwest. Between 1850 and 1860, he sold upwards of 150,000 pounds of dried crude botanical drugs to northern buyers, including two of his best customers, Tilden & Co. and the Shakers, both of whom purchased about 40,000 pounds each. According to Manget, during that 10-year period, Cowles sold about 11,000 pounds of lady’s slipper root. However, after his first two years of business, the supply became scarce, and by the beginning of the Civil War in 1861, despite high demand, there was practically no supply.32

Recognition of Threats and Rarity

These mostly hardy, terrestrial orchids are among the most attractive and charismatic plant species. A treaty known as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) lists all orchids under various categories of conservation concern and tracks their international trade. Orchids are members of the largest plant family (Orchidaceae), which has more than 27,800 species. Collection for both the horticultural trade and, to a lesser extent, the medicinal botanical trade, has put pressure on wild orchid populations for centuries.33

Contemporary awareness of medicinal plant conservation took root in the context of CITES conformity. In February 1988, the Office of Management Authority (OMA) of the US Fish and Wildlife Service (FWS), which is the authority for CITES enforcement in the United States, issued a bulletin on “Export of Ladyslipper.” It read:

It has come to our attention that U.S. dealers are shipping ladyslipper roots overseas for use in foodstuffs or for medicinal purposes. Ladyslippers … species of Cypripedium … are orchids and, therefore, are protected under the Convention. All exports of ladyslippers, or parts of ladyslippers, must be accompanied by an export permit issued by OMA. If you wish to move ladyslipper plants or parts internationally, you must contact OMA to apply for a Convention export permit. Contact OMA also for information concerning Management Authorities of other countries of ladyslipper origin if you wish to import such material into the United States.34

Botanical Trade Develops Response

Although CITES regulations regarding American ginseng (Panax quinquefolius, Araliaceae) were well-known in the herb trade in the 1980s, the application of CITES regulations to other herbal products garnered little attention. Notice of the “export control of ladyslipper” was reported in HerbalGram issue 15 in 1988.35 Later that year, at the June 20, 1988, annual meeting of the International Herb Growers and Marketers Association (IHGMA), held in Baton Rouge, Louisiana, this author introduced a resolution that was adopted by the organization’s members and later by the American Herbal Products Association (AHPA). It stated:

Whereas the roots of Lady’s Slipper Cypripedium spp. (notably C. acaule, C. calceolus var. pubescens, and C. calceolus var. parviflorum) have historically been traded as wild botanicals, given the recognition of the threatened status of these and other orchids resulting from extirpation for commercial purposes and other causes, the IHGMA/AHPA hereby encourages and requests its members and all other businesses and individuals in the horticultural and herb trade to refrain from trade in wild-harvested Lady’s Slippers, once current stocks in possession are sold, and from the 1988 season forward. IHGMA/AHPA further encourages its members and others in the herb trade to support research in the ecology, demographics, cultural methods, plus sexual and asexual propagation of Cypripedium species.36

In July 1988, American Botanical Council Founder and Executive Director Mark Blumenthal presented the resolution to AHPA, and it was subsequently adopted at the AHPA meeting in Las Vegas, adding the weight of the mainstream herb industry to awareness of lady’s slipper conservation.

Shortly after the resolutions were passed, Nature’s Way Products, Inc., then based in Springville, Utah, announced it would no longer purchase lady’s slipper root. At the time, this was seen as the first action by a major herb company to stop buying an ingredient strictly for environmental reasons.37

Ken Murdock, president of Nature’s Way at the time, noted: “It is now clear that we must intervene to assure the survival of Lady’s Slipper. Since Nature’s Way has a great interest in the long-term viability of all botanicals, we will cease purchasing Lady’s Slipper for commercial use.”38

In short order, “sources indicated that collectors can’t give it away because the industry has been so effective in dealing with the conservation issue,” according to an update in HerbalGram issue 18/19.39

In the later 20th century, the horticultural trade may have contributed to greater decline in lady’s slippers than did the medicinal botanical trade. “Wild-dug” native plants became an issue in the 1980s and 1990s, including the offering of “nursery-grown” plants, which rather than being propagated were simply wild-dug plants held in pots or cultivated beds for a year or two before being offered for sale. This problem was exposed to a broader audience, including conservation groups, native plant societies, botanists, and horticulturists, at the 1989 meeting of the Eastern Native Plant Alliance. Conservation efforts also were initiated through the Natural Resources Defense Council’s plant conservation project and the World Wildlife Fund. At the time, successful consumer-based educational campaigns alerted gardeners to this problem, which increased awareness and led many consumers to ask nurseries whether native plants were propagated before purchasing them.40

Since the 1990s, advances have been made in the propagation of Cypripedium species by seed and through tissue culture and other breakthroughs in micropropagation techniques. This has helped re-establish a horticultural trade in propagated lady’s slippers and the development of a range of hybrids for plant collectors. However, it takes a long time to propagate plants that are large enough to re-establish in the wild or offer for sale in the horticultural trade, so this is expensive. This has relegated lady’s slipper propagation to well-funded conservation programs and, in private commerce, to terrestrial orchid enthusiasts who are willing to pay $45.00 or more per plant.41

Now, in the context of creating biomass for medicinal or herbal use, the technology and the need simply do not exist for a commercial supply of this botanical ingredient of historical conservation concern. According to AHPA’s 2011-2017 Tonnage Survey of Select North American Wild-Harvested Plants, the aggregate amount of dried Cypripedium root that entered trade between 1999 and 2017 was limited to only 3.62 pounds.42

In 1996, Primack wrote that in the early 20th century one of the threats to pink lady’s slipper was gardeners who attempted, with little success, to transplant this beautiful New England orchid to their own yards. A media campaign to discourage the practice and respect the plant, along with the renewal of previously disturbed habitats, helped the plant recover. Where once only a few scattered plants survived, dozens, hundreds, even thousands of plants became re-established in the last half-century. Symbiotic soil fungi, necessary for the plant’s survival, reappeared with the recovered habitat.14

The perception that humans should leave lady’s slipper orchids alone in the wild seems to have taken hold. For the herb industry, it became a success story when awareness of this developing conservation issue came to light and led to rapid action that virtually removed the ingredient from the commercial supply chain. Ultimately, lady’s slipper orchids are an excellent example of nature’s resilience and power to recover when humans change their behavior and interact with the plant world in symbiotic harmony.

Steven Foster is an author, photographer, and herbalist, and he serves on the Board of Trustees of the American Botanical Council. He began his herbal career in 1974 at the Herb Department of the Sabbathday Lake Shaker Community.

* Here, Lloyd is referring to Eclectic physician John King, MD (1813–1893), whose The American Eclectic Dispensatory, published from 1852 to 1905, is a standard work known as King’s American Dispensatory, along with George B. Wood, MD (1797–1879), and Franklin Bache, MD (1792–1864), co-authors of the standard pharmacy reference The Dispensatory of the United States of America, which included their byline from 1833 (1st edition) until 1880 (14th edition).

The Shakers are a celibate communitarian Christian group who first settled in Watervliet, New York, in 1776. By the 1850s, more than 6,000 Shakers were gathered in 16 communities from Maine to Kentucky. Their religion is expressed in celibacy, community of goods, non-resistance, and equality of the sexes. They began selling herbs by 1800, offering more than 300 species in their catalogs of the mid-19th century, and still grow herbs and package herbal products at their single remaining active community in Sabbathday Lake, Maine.


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