The Monthly Orchid—a Letter to the Earth

… its broad extremity is folded over and backwards in a peculiar manner, so as to form a sort of shoe ... Hence arises the English name of Lady's Slipper. (photo by Matt Lavin).

Let me start by explaining how honored I was when Ms. Plantsandrocks asked me to contribute to her series about Orchids while she is traveling in The Dakotas. My knowledge of the family is vast, but I fear it may be a bit outdated. However, the heart-felt joy that I find in Orchids has not diminished, and I hope to share some portion of it with you. By the way, I was advised to write in a straightforward manner, as the eloquence of my day has gone out of fashion. I shall try my best in that regard, but can make no promises, being very much a man of my times. (1)

I believe some of you are acquainted with my book, Fertilisation of Orchids, described by Ms. Plantsandrocks in an earlier article. It was issued shortly after On the Origin of Species, with the intention of demonstrating that I had put much effort into finding evidence and case studies in support of natural selection. During the summer of 1839, and the one previous, I had been strongly drawn to the cross-fertilisation of flowers by insects, having come to the conclusion that crossing played an important part in keeping specific forms constant. I attended to the subject during every subsequent summer, my interest greatly enhanced by having read C. K. Sprengel's wonderful book, Das entdeckte Geheimnis der Natur.

The Secret of Nature in the Form and Fertilisation of Flowers Discovered, CK Sprengel 1793 (source).

My little orchid book cost me ten months’ work, but it was a sound investment. Since its appearance, a surprising number of papers and separate works on the fertilisation of all kinds of flowers have appeared; and these are far better done than I could possibly have effected. The merits of poor old Sprengel, so long overlooked, are now fully recognised many years after his death.

Let me move now to the Orchids, specifically the Lady’s Slippers, which I was told grow in The Dakotas in the heartland of America (2). However, in case any one should visit this post who has never attended to Botany, it may be convenient to explain the meaning of the terms used. We shall look at flower parts for which Orchids are distinctive, in comparison with common flowers. It may be helpful to follow the illustration immediately below (not mine; provided by Ms. Plantsandrocks).

A typical orchid flower (Sereno Aceto).

In common flowers, the stamens (male organs) surround one or more female organs, called pistils. In contrast, almost all Orchids have only one stamen, which is confluent with the pistil forming what we call the Column. As in common flowers, the Orchid stamen has an anther which carries pollen—the male vivifying element. However, in contrast with the pollen of common flowers, which consists of fine granular powder, in most Orchids the grains cohere in waxy masses called Pollinia.

Regarding the female organs, most Orchids have three united pistils. The upper part of the pistil is soft and viscid; this is the stigma. During the act of fertilisation the stigma is penetrated by long tubes emitted by the pollen grains; these carry the contents to the ovules (young seeds). However, the stigma of the uppermost of the three pistils has been modified into an extraordinary organ, called the Rostellum to which the Pollinia are attached! The Pollinia along with part of the Rostellum are removed by insects, and perhaps transported to another plant of the same species.

I will describe only briefly the outer divisions of the Orchid flower. The three outermost are the Sepals, generally coloured like the three inner ones, the Petals. The lowest Petal is larger, and often assumes a most singular shape; it is called the lower lip, or Labellum. It secretes nectar, thereby attracting insects.

The Labellum forms the slipper of the Greater Yellow Lady’s Slipper (MWI).

Now we shall discuss the genus Cypripedium, the principle object of this article. It is quite unusual, differing from other Orchids far more than any other two do from each other. An enormous amount of extinction must have swept away a multitude of intermediate forms, and left this single genus as a record of a former and more simple state of the great Orchidean Order. So let us look closely at the Lady’s Slipper, perhaps one of the most primitive of today’s Orchids.

Cypripedium pubescens; Catesby 1754, The natural history of Carolina, Florida ... (source).

Species in the genus Cypripedium possess no rostellum, and all three stigmas are fully developed and fully united (s. in illustration below). The single anther characteristic of all other Orchids is here rudimentary (a.), while the two anthers reduced in other Orchids are here fertile (a’.). Finally, the pollen-grains are glutinous and not united into waxy masses. There are other fascinating differences, but these are too minute and complex for anyone who has not a strong taste for Natural History. If you would like to know more, please refer to my book, starting on page 270.

Cypripedium, upper part of Labellum removed. I am much indebted to Mr. G.B. Sowerby for the pains which he has taken in making the Diagrams in my book as intelligible as possible.

We arrive at last at fertilisation and the role of insects, a subject to which I have devoted much time and thought. But first I shall explain the context in which I struggled—likely it will strike you modern thinkers as preposterous. In my time it was widely assumed that most flowers, being hermaphroditic (having both male and female parts), were self-fertilising. Even more shocking, it was only during the early years of my century that the idea of sex in plants finally emerged from the mists of profitless discussion and feeble experiment (3).

From Die Alpenpflanzen nach der Natur gemalt, F. Tempsky,1879-1884 (source).

At first glance the Lady Slipper appears to present an obstacle to fertilization by insects. As you can see in the illustration above, its broad Labellum is folded so as to form a sort of shoe, the end closed to any entry. However, close examination reveals two narrow slits through which an insect can reach with its proboscis the nectar waiting at the bottom of the Labellum. Most importantly, it can only do this by brushing against the two fertile anthers, thereby smearing its proboscis with the glutinous pollen. 

I tested this myself, by inserting a bristle which became smeared with pollen. We thus see how important, or rather how necessary for the fertilisation of the plant, is the curious slipper-like shape of the Labellum, in leading insects to insert their probosces by the lateral passages close to the anthers. The efficacy shown by nature is truly striking.

To those of you who have stayed with me to the end of this article, I am immensely grateful. More than a century has passed since I last spoke of Orchids and fertilisation with fellow naturalists on Earth, or so I was told (I have no sense of time passing). It is my sincere hope that you encounter this beautiful flower in its natural setting, and that you look closely and take the time to appreciate the cleverness of Evolution’s hand (4).

Charles Darwin, M.A., F.R.S., &c.

Greater Yellow Lady's Slipper in the wilds of Minnesota (MWI).

Notes

(1) This article was edited for greater concision and clarity, but without altering style or content. However, do NOT use it to quote Mr. Darwin. Instead use the Sources listed below.

(2) The yellow-flowered Lady’s Slipper in South Dakota is Cypripedium parviflorum var. pubescens. Its synonymy is lengthy: C. pubescens, C. flavescens, C. calceolus, C. calceolus var. pubescens, C. parviflorum var. planipetalum, and C. veganum. Our white-flowered species are C. candidum and C. montanum.

(3) This was explained by the author’s son, Francis, in his introduction to Chapter VII, "Fertilisation of Flowers" in The Life and Letters of Charles Darwin. See page 257.

(4) In South Dakota, Cypripedium parviflorum var. pubescens, the Greater Yellow Lady’s Slipper, has been found in wet meadows in the far eastern part of the state.

Sources

Barlow, Nora (Darwin's granddaughter), editor. 1958. The Autobiography of Charles Darwin, the first complete version. Darwin online

Darwin, Charles. 1862. Fertilisation of Orchids. On The Various Contrivances By Which British And Foreign Orchids Are Fertilised By Insects, And On The Good Effects Of Intercrossing. Darwin Online

Darwin, Francis, ed. 1887. The Life and Letters of Charles Darwin, including an autobiographical chapter. Volume 3. Darwin Online

The Monthly Fern??—Prairie Spikemoss

Selaginella densa—moss, fern, fern ally, or none of the above? Coin is 19 mm across.

This month the South Dakota fern series features another oddity—a spikemoss, genus Selaginella. It's even more unusual than last month's Water Clover, for while water clovers are ferns, spikemosses are not, at least not anymore. So where in the greater scheme of plant classification do they belong?

The Prairie or Dense Spikemoss, Selaginella densa, is the more common of South Dakota's two spikemosses. It occurs in the Black Hills and scattered across the west half of the state. If you live in or have wandered across the Great Plains or Rocky Mountains, you may have seen it, for it grows on a wide range of sites—prairies, alpine meadows, dry rocky slopes, rock crevices, sandstone, quartzite or granite rock, and dry gravelly, clayey or sandy soil (Flora North America). Or maybe you overlooked it, as I used to do. After all, it looks very much like a moss (1).

Spikemosses were first classified—given a name and assigned to a plant group—by the great Swedish botanist Carl Linnaeus, founder of today's system of naming organisms. In his Species plantarum (1754) he placed them in the CRYPTOGAMIA MUSCI section—the mosses. That was a big mistake, but at the time it was a reasonable decision. Like mosses, Selaginella produces spores (2). But unlike mosses, it has vascular tissue—plumbing for transporting water and nutrients.

In the late 1890s another Swedish botanist was studying spikemosses, while preparing a Catalogue of the Flora of Montana and the Yellowstone National Park. Per Axel Rydberg had emigrated to the United States in 1882, hoping for a career as a mining engineer. But after a serious injury in an iron mine in Michigan, he moved to eastern Nebraska to teach mathematics. He also studied botany at the University of Nebraska—the beginning of a "lifelong devotion to plant studies" in the Great Plains and Rocky Mountains (source).

In 1895 and 1896, Rydberg was sent to Montana by the US Department of Agriculture to collect grasses and forage plants. The next summer he returned, with the first field expedition of the New York Botanical Garden. He made about 1800 collections representing 800 species—20,000 specimens in all (replicates were collected for exchange or sale to other institutions).

Rydberg's Catalogue included a large foldout map showing localities mentioned in the text. He noted that the eastern half of the state was "practically unexplored botanically." (BHL)

Going through his collections that winter, Rydberg saw that the flora of Montana was poorly known, even with his additions. "It was therefore considered advisable to extend the work and study all the material from the state that was accessible." He examined specimens from 16 institutions and private individuals, ranging from the Lewis & Clark collection (1803–1804) to the Montana Ladies' [Columbian] World's Fair Set (1893). By the time the Catalogue was published in 1900, Rydberg had added 776 species to the flora of the Rocky Mountain region, including 163 novelties—species new to science (Rydberg would become known as a notorious splitter).

Among the novelties was a low densely-tufted plant with very short stems covered in bristle-tipped leaves 3–5 mm long. Fertile stems were taller, to c. 4 cm, with spore-bearing leaves (sporophylls) neatly arranged in four ranks, forming terminal strobili (aka cones).

Prairie Spikemoss forms dense mats in this soil crust. Matt Lavin photo.

Selaginella densa's 4-angled strobili rise above very short sterile stems that look like clusters of bristle-tipped leaves. cinthyadasilva photo.

Rydberg knew the plant was a spikemoss, but the dense "moss-like" form was not something he had seen before. After careful study of seven specimens, he concluded it was a new species, calling it Selaginella densa. The holotype (basis for formal description) was a specimen collected in 1889 by Valery Havard, a French-born American military physician, explorer and botanist.

Havard identified his specimen (NYBG) as S. rupestris, which is widespread in the east half of the US.

In his Catalogue Rydberg followed the accepted classification of the day. He included Selaginella densa in the Pteridophytes—spore-bearing vascular plants, mainly ferns. He put it near the end of the section, with horsetails, clubmosses and other oddballs. These were the Fern Allies. Like ferns they bore spores, had vascular tissue, and reproduced via two distinct independent life stages. But otherwise they were decidedly unfernlike, and very different from each other. Just look below!

Horsetails and scouring rushes, genus Equisteum, have jointed stems with cylindrical sheaths tipped with teeth. These are thought to be highly modified leaves. Spores are born in terminal cones.

Unbranched species of Equisetum are called scouring rushes. Andre Zharkikh photo.

Whisk ferns, genus Psilotum, have linear shoots that fork in the upper half. Minuscule scale-like leaves subtend globose spore containers 2–3 mm across.

Sideways view of a whisk fern. Mary Keim photo.

Quillworts, genus Isoetes, are aquatic, with grass-like clusters of linear leaves. Spores are born in sac-like structures in enlarged leaf bases.

Bolander's Quillworts in a lake in the Wasatch Mountains, Utah. Andrey Zharkikh photo.

Clubmosses, family Lycopodiacee, are a more diverse group, with 7 genera and 27 species in North America. Some are suggestive of spikemosses; in fact spikemosses were put in the genus Lycopodium by Linnaeus.

These clubmosses, all formerly genus Lycopodium, are now 4 separate genera; from Ferns and Evergreens of New England, 1895 (BHL).

The Fern Allies group came into use in the early 1800s, as a catchall for diverse, puzzling, somewhat fernlike plants. But after about a century botanical experts began to object. Some Allies appeared to be more closely related to ferns, others not so much. Then less than a century later, the Allies got caught up in a revolution. Biologists were switching to a phylogenetic approach to classification. In a nutshell (a very tiny one), they now hope to classify organisms based on evolutionary relationships, i.e., so that all members of a group share a common ancestor. The Fern Allies do not, so they were reclassified (3).

The commonly accepted classification splits the Allies into two groups that diverged long ago, early in the evolution of vascular plants. One includes ferns, horsetails, whisk ferns and seed plants. The other group is much smaller, a collection of relatively primitive plants: quillworts, clubmosses and spikemosses. These are lycophytes (answer to question at top of post). For a longer summary, see The Ferns and their Allies at Cliffnotes. For a deep discussion, start with Pteridophyte taxonomy on Wikipedia.

Fern and lycophyte classification from the Pteridophyte Phylogeny Group. Black labels added, not sure how that guy in the corner snuck in.

Notes

(1) Not all spikemosses are as humble and mosslike as ours. Selaginella is a large genus with c. 800 species, mainly of the tropics and subtropics. In hospitable habitat, spikemosses can be quite showy—some are iridescent!

Selaginella uncinata, Blue Spikemoss, is native to moist shady sites in southern Chile and is widely cultivated; leaves are 3–4 mm long (Flora North America). GKA Dickson photo.

(2) Actually Linnaeus couldn't decide whether "fern dust" was pollen or seeds. The concept of spores would come later.

(3) It's been really hard to give up Fern Allies! It's such a handy label for those diverse kinda-fernlike species. Not surprisingly, the name hasn't gone away. Sometimes it appears under an alias, for example "Fern Relatives" in Ferns of Northeastern and Central North America (2005). More often it pops up in casual conversation, or is used by older botanists who haven't bothered to learn the new scheme. After resorting to "Fern Allies" in a message to pteridologist Robbin Moran, I committed to learning it (Robbin is much too kind to disapprove directly, but he did refer to "lycophytes" in his reply).

Sources (in addition to links in post)

Cobb, B, Farnsworth, E, Lowe, C. 2005. Ferns of Northeastern and Central North America. 2nd ed. Peterson Field Guide Series.

Linné, Cv. 1754. Species plantarum v2. BHL

Moran, Robbin. 2004. A Natural History of Ferns. Timber Press.

Rydberg, PA. 1900. Catalogue of the Flora of Montana and the Yellowstone National Park. Memoirs of the New York Botanical Garden. BHL

Monthly Fern: polypodies & fern sex (or do they?)

Left, Polypodium saximontanum, leaves to 25 cm long (Matt Berger); right, P. virginianum, leaves to 40 cm long.

For May, the South Dakota "Monthly Fern" series features polypodies—Polypodium saximontanum and P. virginianum. The genus name comes from the Greek "poly" meaning many and "podion" meaning little foot, referring to the bumps (old leaf bases) on the creeping stems. Polypodies occur worldwide, but are more common in the Northern Hemisphere. About 100 species are recognized, with 11 in North America. They grow mostly on rock (source).

Creeping stem (rhizome) of Common Polypody; bumps on right are old leaf bases. © 2007 Robbin Moran.

South Dakota's two polypodies have a notable distribution—one on each side of the state. P. saximontanum, Rocky Mountain Polypody, grows on granite outcrops in the Black Hills, in the far west. P. virginianum, Common Polypody, is restricted to a small area of Sioux quartzite, in the far east very close to Minnesota (where it's common). It's a good thing they live 350 miles far apart. They're very similar and would be difficult to distinguish if their ranges overlapped.

South Dakota polypodies: Rocky Mountain Polypody in Black Hills (green dot); Common Polypody in Minnehaha County (pink dot); SEINet search May 2025.

Rocky Mountain Polypody on granite, Black Hills, SD (JD McCoy).

Common Polypody on Sioux quartzite, Palisades State Park, SD.

Both species have evergreen leathery deeply-lobed leaves with straw-colored stems. Common Polypody leaves tend to be longer and wider than those of Rocky Mountain Polypody (see first photo). No other clear differences in vegetative characters were found in published descriptions.

As for reproductive structures—which are critical for fern id as we've been told repeatedly—the South Dakota polypodies again are very similar. Both have round sori (spore clusters) arranged in two rows on the underside of leaf lobes; indusia (covers) are absent. The spores are yellow, so much so that even though they're housed in brownish sporangia, they give the sori a yellowish cast.

Common Polypody, P. virginianum (MWI).

Rocky Mountain Polypody, P. saximontanum (Kelly Fuerstenberg).

It is possible to distinguish Common and Rocky Mountain polypodies based on their sori, but it isn't easy. Both have sporangiasters—tiny transparent jelly-like blobs separating the sporangia (1). In P. virginianum, most sporangiasters have gland-tipped hairs, while in P. saximontana, gland-tipped hairs are few or absent. Be forewarned—sporangiasters are said to be so small that one needs macro photos or a good hand lens to examine them.

Polypodium virginianum sori, with sporangiasters with gland-tipped hairs. © 2007 Robbin Moran (arrows added).

Sporangiasters with and without glandular hairs, Polypodium amorphum; very helpful photo by James Thomas.

While we're on the subject of "reproductive" structures, let's address a common misconception (fern buffs excepted). Strictly speaking sori, sporangia and spores are not reproductive structures, for ferns cannot reproduce themselves directly. Instead, their spores give rise to plants quite unlike the parent fern.

This leads us to the fern life cycle, the so-called bugbear of beginning botany students. But we can dispense with complicated details and off-putting terms and still understand and appreciate the curious life of ferns. They and their relatives the lycophytes (formerly "fern allies") are the only land plants that exist as two different free-living beings—kinda like a butterfly and its caterpillar (2).

I find it helpful to first think about flowering plants (angiosperms) with their familiar sex organs. Flowers have eggs in ovaries and sperm in pollen. When a cell of each joins in fertilization, the result is a seed. If conditions are right, the seed germinates and grows into a plant like its parent.

Angiosperm life cycle; note the single free-living being—the plant (modified from source).

But ferns are different. Instead of seeds, they produce millions of tiny asexual spores. If conditions are right, a spore germinates and grows into a minute green plant very different from its parent, even though they have the same DNA. I find this so cool to think about! Unfortunately there seems to be no user-friendly term for these little beings, only "gametophyte" or "prothallus".

Gametophyte of Polypodium vulgare (light microscope at x4 magnification); Viséan.

John Lindsay, a British surgeon working in Jamaica, was the first to describe fern gametophytes (1794), though he didn't call them that and didn't fully understand what they were. Hoping to figure out how ferns reproduce, he had sprinkled "dust" from a fern leaf (today's spores) on dirt in a flowerpot. "I placed the pot in a window of my room, watered it daily, and every day or two examined a small portion of the [dirt] by the microscope ... but observed no alteration till about about the 12th day after sowing." At that point the soil began to turn green "as if it were covered with some small moss".

Lindsay made a nice drawing showing the stages of fern development he observed (full illustration here).

Excerpt from Lindsay's drawing: top, germination; lower right, tiny scales; lower left, first fern leaves.

With the microscope Lindsay could see particles of dust germinating—"pushing out their little germ, like a small protuberance, the rudiment of the new fern" (8–11 above). After a few more weeks the "moss" had grown enough to be visible to the naked eye, looking like small scales (13). These grew to be roundish and bilobate, similar to liverworts (14). Finally a tiny leaf emerged from the scale (15), followed by larger ones (16) until there was a fern like the one that produced the dust. Understandably, Lindsay concluded the dust was fern seed.

It wasn't until the 1840s that botanists finally got rid of fern seed. It had become obvious that despite their alluring beauty, ferns are not sexual creatures. That honor belongs to their gametophytes.

A typical gametophyte, with antheridia and archegonia (source).

On the underside of a gametophyte are little bumps that come alive in the presence of water. Some release wriggling spiral filaments that swim away. Others open to receive a spiral filament if one happens by. These are sex organs: male antheridia release wriggling sperm, and female archegonia each contain an egg. If a sperm wriggles down the neck of an archegonium, it arrives at a large cell—an egg. Fertilization produces a zygote, which develops into a baby fern growing out of the gametophyte (15 in Lindsay's drawing above). If conditions are right, it will become a full-sized fern, thereby completing a life cycle.

Here's the life cycle of a fern, emphasizing the two independent free-living beings that make it so cool! (3)

Fern life cycle—green fern (aka sporophyte) and brown gametophyte (Sigel et al. 2018, much modified).

Once again I'm ending a post without addressing a promised topic. With ferns, it's too easy to go down a rabbit hole! So I will do another Monthly Fern for June—about "the burning question" of how many fern spores fit in a Coke can. What's your guess? Here's a hint: a typical soda can holds 0.355 liters (1.5 cups). And here's an average-sized spore:

Polypodium virginianum spore. Copyright © 2007 by Robbin Moran.

Notes

(1) Sporangiasters may help keep sporangia from drying out prematurely (source). Moran (2017) notes that "In immature sori they form a continuous, protective covering over the young sporangia, thus acting like an indusium."

(2) In thinking about ferns and gametophytes, butterflies and their caterpillars came to mind. In both cases, two forms are produced from the same DNA by using different genes. This is dramatic in butterflies and caterpillars, but not so much in ferns and their gametophytes. In fact, Sigel et al. (2018) found a nearly 90% overlap in genes expressed in Polypodium amorphum ferns and gametophytes. And there's an even bigger difference. Butterflies and caterpillars are both diploid (two sets of chromosomes); there is no independent haploid form that produces gametes—no equivalent of the fern gametophyte. So my comparison of butterflies and ferns was a stretch.

(3) Strictly speaking all land plants alternate between sporophyte and gametophyte life stages (spore- and gamete-producing). But only in ferns and lycophytes are both stages free‐living beings. In seed plants only the sporophyte is free-living; in mosses and liverworts, only the gametophyte is free-living. More here.

Sources in addition to links in post

Lindsay,  John. 1794. Account of the Germination and Raising of Ferns from the Seed. Trans. Linn. Soc, London 2:93–100. BHL.

Moran, RC. 2004. The Natural History of Ferns. Timber Press.

Moran, RC. 2017. Division Polypodiopsida, Ferns in New Manual of Vascular Plants of Northeastern United States and Adjacent Canada. NYBG Press Digital Content (not available as of June 2025, pers. comm.)

Rothfels, C. 2022. Fiddleheads: Fern life cycles and identification. Online workshop for Jepson Herbarium (videos).

Sigel, EM, et al. 2018. Overlapping patterns of gene expression between gametophyte and sporophyte phases in the fern Polypodium amorphum. Front. Plant Sci. 9:1450. FREE

USDA Forest Service. Fern Reproduction.

Osage Orange—God's Gift to the Prairie Farmer

"this curious fruit, which, when first discovered lying neglected beneath the tree, led the voyagers to fear and report it as a poison" wrote Thomas Nuttall (1842). Pete unseth photo.

In March of 1804, Meriwether Lewis, co-captain with William Clark of the Corps of Discovery, stopped at the home of trader Pierre Chouteau in St. Louis (Missouri Territory). The Chouteau brothers were supplying their expedition, which would depart in May, but this visit was for another matter. Lewis wanted to see Chouteau's garden.

President Thomas Jefferson had appointed Lewis expedition botanist. He was to study and record "the soil & face of the country, it's growth & vegetable productions, especially those not of the U.S. and the dates at which particular plants put forth or lose their flower, or leaf" (source). Given this assignment, there was good reason to visit Chouteau. The trader had lived in Louisiana Territory since birth, knew the Osage Indians well, and was familiar with their use of native plants, some of which he had planted in his garden.

Pierre Chouteau; Missouri Historical Society.

Lewis took cuttings from Chouteau's trees, and sent them to Jefferson, with a letter of explanation:

"I send you herewith inclosed, some slips of the Osages Plums, and Apples. I fear the season is too far advanced for their success. Had I earlyer learnt that these fruits were in the neighbourhood, they would have been forwarded at a more proper time ... I obtained the cuttings, now sent you, from the garden of Mr. Peter Choteau (1), who resided the greater portion of his time for many years with the Osage nation ..."

In his letter Lewis also explained the value of the Osage Apple (today's Osage Orange), presumably learned from Chouteau. "So much do the savages esteem the wood of this tree for the purpose of making their bows, that they travel many hundred miles in quest of it." Decades later, the tree would be highly esteemed by farmers as well—on the great sea of grass to the west.

In 1810 or thereabouts, another botanist visited Pierre Chouteau's garden. Thomas Nuttall, recently arrived from England, took a particular interest in the Osage Apple, which had not yet been introduced to science. He published the new species in 1818, naming it Maclura aurantiaca to honor his friend, geologist William Maclure; aurantiaca means orange, referring to the color of the wood. In 1906, this was replaced with the currently accepted name, Maclura pomifera (2).

"The wood is very heavy and of a Saffron yellow ..." wrote Nuttall (1818). Fernando Lopez Anido photo.

Nuttall's description was incomplete. For one thing, he hadn't seen any male flowers (Maclura flowers are unisexual; trees have either male or female flowers). This did not keep him from publishing, for the female flowers, and especially the fruit, are what make the species so distinctive.

Nuttall noted that Maclura's female flowers are arranged in dense globose clusters. Though tiny, each one has a style nearly an inch long. At maturity the 1-seeded fruits of the many flowers in a cluster coalesce into a "compound berry" (now known as a multiple fruit) containing "pulp nearly as succulent as that of an orange, sweetish and perhaps agreeable when fully ripe" (Nuttall also lacked information concerning edibility).

Maclura's female inflorescence of numerous tiny flowers, each with a long narrow style. H. Zell photo.

The Osage Orange is a multiple fruit (Nuttall's compound berry). H. Zell photo.

Multiple seedlings from a multiple fruit. Cbarlow photo.

Thirty years later, Nuttall, by then an acknowledged expert on the North American flora, was engaged in a monumental project—three supplemental volumes to François-André Michaux's North American Sylva (forest trees). Among the added species was Osage Orange. It appeared in the first volume, with a lengthy description and two beautiful plates.

Osage Orange, also called Bois d'Arc meaning Bow Wood (3): branch of a male plant on right, note the stout thorns; female flowers with long styles lower left; source.

Osage Orange; cross-section showing flowers united to form a multiple fruit; source.

Nuttall now had better information about edibility: "The fruit, when ripe, is succulent, has a sweetish but insipid taste, and is somewhat acrid. As far as we know, it is not eaten by any animal" (4). Also of interest (and timely) was an item in his description of the wood: "Another important use of the Maclura ... is that of forming live fences or hedges, for which purpose it is well adapted, as it bears cutting, grows close, and is very thorny."

OSAGE ORANGE—Can any one tell us more of this tree? We are desirous of having our columns made the vehicle for communicating information of any material that may be made valuable for hedging. This tree ... seems well adapted for that purpose; and if any has been used in Missouri or elsewhere, it would be a great favor to have an account of it furnished us. The Prairie Farmer, Vol. 1 No. 1, January 1, 1841.

While Nuttall was finishing his first volume, John A. Wright, a real estate speculator in the muddy young town of Chicago, was pursuing his dream. He wanted to help farmers who were struggling on the great sea of grass stretching a thousand miles to the west—"an open plain, so barren of timber, so huge of expanse as to bewilder, often frighten, them." The accumulated wisdom of settlers in wooded country to the east was of little use. Instead of clearing trees, prairie farmers toiled to break thick tough sod. And in the absence of trees, wood had to be imported at great expense (Lewis 1941).

No trees? Use sod! Soddy (sod house) in 1901; photographer unknown.

The need for helpful information was dire. Toward this end, Wright drummed up financial support for a non-partisan apolitical newspaper specifically for farmers. Though he had never farmed himself, he agreed to be the editor. On January 1, 1841, the first issue of The Union Agriculturalist and Western Prairie Farmer (soon shortened to The Prairie Farmer) was published (5).

On the front page, Wright appealed to readers for help:

TO THE PRACTICAL FARMER—Upon you we must rely for the matter that is to make this paper interesting and valuable. ... What we wish is this—as soon as any one obtains any valuable agricultural information, a recipe, a plan, or any other matter that would be adapted to our paper, that he would sit down immediately and communicate it. In this manner communications will be more to the point than if writers delay till they can collect several facts. ... if as soon as a farmer obtains one fact, he sends it, it will be what we want—"short and sweet."

Wright was well aware that some, perhaps many, would hesitate to contribute:

Many farmers may perhaps decline communicating their knowledge, because they may feel themselves incompetent to write for publication. To such we would say, that we most earnestly request you to send us articles, and should there be a word mis-spelt, or a sentence that might be improved by a little alteration, we will use our endeavors to make it right. What we want are facts—and perhaps a fact a farmer might possess, and which he declines sending, because he may perhaps not have enjoyed advantages of education in early life, might be of more service to the West, than all the matter we might publish in several numbers [issues].

Among Wright's passions was fencing, understandably. One of the biggest problems farmers faced was marauding wildlife and livestock. The cost of imported wooden fence was prohibitive and wire fences of the day—horizontal unarmed strands—were ineffective. So farmers tried hedges, also called living fences. Wright had read in the Hartford Silk Culturalist that Osage Orange trees made excellent hedges, and included that article in his paper. The final sentence was especially persuasive:

On the best authority, I am assured that the trees of the Osage Orange, when set at the distance of fifteen inches asunder, make the most beautiful as well as the strongest hedge fence in the world through which, neither men nor animals can pass.

Osage Orange—gift from God? JM DiTomaso photo (CC 3.0)

Osage Orange was soon a hot topic, with readers begging for information on where to buy viable seed and young plants. Fortunately Professor JB Turner of Illinois College had taken an interest. In the 1830s he had crossed "these beautiful prairies for some thousands of miles on horseback" concluding that whoever produced cheap effective fencing would go down in western history as the "greatest moral, intellectual, social and pecuniary benefactor." Perhaps in hopes of being that benefactor, Turner began a study of Osage Orange, periodically reporting his progress in The Prairie Farmer.

By 1848, Turner was convinced that "the Osage Orange is the shrub that God designed especially for the purpose of fencing the prairies." That November he announced he had plants for sale. He didn't know the exact price, but estimated a hedge 80 rods long (c. 1300 ft) would cost less than $15. By 1853 the price had dropped to $25 per mile, while a wooden fence "would cost $300 a mile and would be gone in 12 years" [due to prairie fires].

But in spite of its many advantages and perhaps divine origin, the Osage Orange hedge fell out of favor after just thirty years, a victim of innovation. JF Glidden of DeKalb, Illinois, had come up with a clever solution for wire fencing—barbs. Business took off immediately. The year after it started as a one-man operation, 70 men were producing three tons of fencing per day! (PF May 1875).

Both cheap effective wire fences and Osage Orange seeds were available in February 1875.

Note the clever design—"two No. 12 wires on one of which are wound the barbs ... they are then twisted holding the barbs immovable in their places" (May 1875).

Many hedges were removed and replaced with barbed wire. Others were simply abandoned. But Osage Orange trees did not disappear. Some were scavenged for fenceposts ...

Maclura posts are dense, strong, and resistant to rot and insects. Original source unknown.

... and Osage Orange hedges are still planted ...

Maclura hedge in Primorsko, Bulgaria; photo by Katya.

... and the legacy of the prairie farmers' blessing is still with us.

Thanks to prairie farmers, Maclura pomifera (dark green) occurs far beyond its original range (light green); from USDA, and Nelson et al. 2014 (6).

Notes

(1) Chouteau signed his letters apropos the recipient—Pierre Chouteau, Pedro Chouteau, and Peter Chouteau for French, Spanish, and English speakers.

(2) Osage Orange has a complicated nomenclatural history. It was first published in 1817 as Ioxylon pomifera by French naturalist Constantine Samuel Rafinesque, who then made a series of name changes: Toxylon pomiferum in 1818, Joxylon pomiferum in 1819. In the meantime Thomas Nuttall named it Maclura aurantica (1818). This became the accepted name perhaps because of Nuttall's greater botanical stature. In 1906 it was renamed M. pomifera, perhaps related to Rafinesque's first-published name. See Smith 1981. Further complications can be found in Reveal & Musselman.

(3) Maclura pomifera has many common names, including Osage Orange, Hedge Apple, Yellow Wood, Monkey Brains, Bow Wood, Bois d'Arc, Bodark and more.

(4) While Osage Orange pulp isn't edible, the seeds are. From Mike on Flickr: Osage orange trees are a magnet for squirrels. They typically sit on the ground at the base of the tree, or on a wide branch up in the tree to disassemble their prize, getting at the seeds. Piles of shredded hedge apples are a sure sign of squirrels in the area. The seeds are edible by people, but one must do like the squirrels, and remove the slimy husk to pick them out of the pulpy fruit.

(5) The Prairie Farmer is still being published, including a digital edition.

(6) The native range of Maclura pomifera is debated and probably irresolvable (Smith 1981).

Sources in addition to links in post

Earle, AS, and Reveal, JL. 2003. Lewis and Clark's Green World; the expedition and its plants. Farcountry Press.

Foley, WE. 1983. The Lewis and Clark Expedition's silent partners: the Chouteau Brothers of St. Louis. Missouri Historical Review 77:131–146. SHSMO

Lewis, L. 1941. Prairie Farmer, its beginnings. Prairie Farmer 11:5–17 (centennial edition). Illinois Digital Newspaper Collections.

Michaux, F-A, Nuttall, T, Hillhouse, AL, and Redouté, PJ. 1842. The North American Sylva; or, A Description of the Forest Trees of the United States, Canada, and Nova Scotia ... Vol. 1. BHL

Nelson, G, et al. 2014. Trees of Eastern North America. Princeton University Press.

Nuttall, T. 1818. The genera of North American plants and a catalogue of the species, to the year 1817 [Maclura 2:233]. BHL

Rafinesque, CS. 1817. Description of the Ioxylon pomiferum, a new genus of North American tree. American Monthly Magazine and Critical Review 2:118–119. Google Books

Reveal, JL, and Mussulman, JA. The Osage Orange; Maclura pomifera, in Discover Lewis & Clark (Lewis & Clark Trail Alliance). Accessed December 2024.