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.

Does Dog Exist? A tail of philosophy, AI, and the pursuit of happiness.

Dog?

In a scan of The Atlantic homepage recently, I came across Are You a Platonist or an Aristotelian? I was especially intrigued by the subtitle: "Your answer may determine how happy you can be." I thought it might be useful given what's happening, both normal (Earth's 23º tilt + orbital position = shorter days) and very much abnormal (US elections).

However not far into the article I was sidetracked from my pursuit of happiness when I learned that "Does Dog exist?" is an eternal question among philosophers, debated at least since 400 BC. Was Plato right? Is there an unchanging ideal that is the true essence of Dog? Or was Aristotle right? Are our diverse too-short-lived dogs all that we have?

September 2014, Uinta Mountains.

September 2024, Canyonlands—our 10th anniversary :)

Having had canine field assistants most of my career, I tend to feel I'm an expert on such topics. Also, I think philosophers delight in making easy questions difficult, for example "Does Dog exist?". But my actual knowledge of philosophy is minuscule, so I queried DuckDuckGo (my preferred search engine).

At the top of the page, above the results, I was offered the services of DuckAssist—DDG's AI—which "scans the web for relevant content and then uses AI-powered natural language technology to generate a brief answer". I was very curious. I clicked on "Generate" and after just a second or two, DuckAssist replied:

"The question of whether a dog truly exists can be explored through philosophical discussions about particulars and universals. A dog, as a particular animal, is undeniably real and can be seen and touched, while the concept of "dog" as a category represents a set of characteristics that define what it means to be a dog."

That's it?! You would think that after nearly two millennia there would be a better answer. Maybe the problem lies with DuckAssist; after all this is a Beta release. So I continued to the two websites it recommended.

The first—Is a Dog Really a Dog? at Philosophy is Not a Luxury—was similar to DuckAssist's answer but much longer. It may have been the main or only source of content. Not convinced that "philosophy is not a luxury", I went to the second recommended site: I wag, therefore I am in The Guardian.

Philosopher in front, student (Mark Rowland) behind; promo photo from The Guardian.

At this site there was nothing about whether Dog exists. Instead, author Mark Rowland discussed dog philosophy in an excerpt from his book, The Happiness of Dogs. Apparently DuckAssist missed the mark by making a common AI error, specifically "Too Eager to Please". But it was a nice coincidence, as my dog does this too.

Just trying to help!

Emmie is half Basenji and therefore bred to kill small animals. This she does eagerly, even those that never lived. Likewise, an AI is driven by its breeding:

"Generative AI needs to create a response to your query, even if it isn’t capable of giving you one ... If the AI doesn’t have enough actual information in its knowledge base, it fills in gaps with stuff that sounds like it could be correct ..." (more here).

But is this really an error? After all, DuckAssist brought me back to the pursuit of happiness. Maybe it read my mind!

Rowland, a philosopher himself, considers dogs "natural philosophers"—they understand "what is important in [life], and how to live it. Philosophers have done their best to address these questions, with limited success. But dogs answer them effortlessly and decisively. Humans think about these questions, but dogs live them."

So much joy in life!

Our problem is that each of us is two beings—"one who thinks and one who is thought about". It's too much thinking that keeps us from being happy. In contrast, a dog—single being that it is—can enjoy something no matter how minor or familiar, and without asking why, or whether it's worth doing.

This certainly is true of Emmie. All it takes is these five words—"Let's go check the mail"—for her to explode with joy. She spins round and round, her small compact body making tight circles along the path all the way to the end of the fence, where she then barks and races off to get any rabbits hiding under the junipers (she has yet to catch one but no matter).

Rowland asks whether humans can ever experience this kind of joy. I too wonder. He says that because we have two lives—"the life that we live and the life that we think about, scrutinise, evaluate and judge"—we can never love life as a dog does. For one thing, a dog doesn't struggle to find meaning in life, while we too often do.

But there's hope. Both Rowland and I are sure that our dogs can help in our pursuit of happiness. We just have to pay attention.

Stay warm.

Maybe yoga will help (Upside-down Dog pose).

What's your purpose in life? To keep your dog happy, of course!

My role model?

NOTE  

The article about philosophy and happiness is by Arthur C. Brooks, a regular contributor to The Atlantic. He argues that Platonists emphasize what they are, which can interfere with happiness, while Aristotelians have greater potential for happiness because they define themselves mainly as works in progress. But he adds, "Neither being nor becoming is exclusively true or exists to the exclusion of the other." I can't say I was persuaded; maybe I didn't fully understand. If you want to give it a try, read the article here.

Tree Following: Killer Cottonwood in Utah

On a hot afternoon several weeks ago, I pulled into Hittle Bottom Campground on the Colorado River in southern Utah. After parking in the only site with shade, I opened the windows, put screens in place, inserted $10 in the payment envelope, and started for the pay station. But I was stopped in my tracks by a Killer Tree, right next to our campsite!

The area around it had been cordoned off with orange caution tape, but I checked carefully to make sure we were safe. Indeed everything was fine. We were out of range of falling limbs.

Click on image to view caution tape, marked by arrows.

The big cottonwoods that grow along lowland rivers in North America—Populus deltoides and P. fremontii —are infamous for dropping large dead branches. As the Colorado AAA has observed:

No one writes poems about “under the spreading cottonwood tree” because it can actually be dangerous to sit under a cottonwood in high winds due to breaking branches.

The technical term for this is "dieback".

Some cities (Denver for example) ban these cottonwoods in part because of dieback. They grow fast (to six feet per year!) and are relatively short-lived, so falling limbs will be a problem. And they grow roots toward and into reliable water sources such as city water and sewer lines! This is an impressive adaptation for the trees but a problem for us (source).

The Hittle Bottom Campground has no water aside from the river, so managers don't worry about cottonwood roots invading plumbing. But dieback is a problem, hence the caution tape. Of course I wanted photos, so I risked my life so in the absence of imminent danger (the day was calm) I stepped over the tape to commune with the Killer Tree.

Zig-zag form due to lost branches.

The bark was especially photogenic, even with tape.

This is Fremont's Cottonwood, named to honor the famous explorer and surveyor John Charles Fremont. However the honor probably celebrates another of his achievements, one less widely known—botanical discovery! Fremont was not a taxonomic expert but he knew how to collect plants. And collect he did—on the order of two thousand specimens. Among these were at least 165 species new to science, some 40 of which were named in his honor. For more about Fremont's botanizing, see JC Fremont was here.

On the afternoon of March 30, 1846, Fremont and his party "encamped on Deer Creek, another of these beautiful tributaries to the Sacramento [River, in California]. Mr. Lassen, a native of Germany, has established a rancho here ...". They stayed for five days, during which time Fremont collected plants, including a cottonwood. He suspected it might be a new species, as he had noted the previous year when he was in southern Utah (no collection was made or survived).

Fremont's 1846 specimen from "Deer Creek at Lassens" (Gray Herbarium). He collected both male (above) and female (below) flowers, demonstrating knowledge and care in collecting plants.

Typical of field botanists at that time, Fremont relied on experts for identification. He sent many of his collections to the leading American plant taxonomist—Asa Gray at Harvard. Gray often passed along western specimens to his colleague, Sereno Watson, who was more familiar with that flora. It was Watson who named and described Populus fremontii.

Sereno Watson (Wikimedia). A colleague described him as "tall, very erect, [with] good features, a high-bridged nose, and a carefully tended beard of great length and whiteness. Almost to the end of his life he walked with a brisk elastic step suggesting physical energy remarkable for a man of his years."

In his 1875 paper, Watson distinguished P. fremontii from its close relatives "especially by the remarkably developed torus" (now called floral disc). He also noted that young growth tended to be somewhat hairy. In contrast, the similar P. deltoides has smaller floral discs and young growth is not hairy.

A century later, James Eckenwalder, expert on the genus Populus, reached the same conclusions, recognizing the larger floral disc and often hairy young growth as distinguishing features for Fremont's Cottonwood (see also his treatment in Flora of North America).

Populus fremontii from Sargent's 1896 Silva of North America; added enlargement shows female flower with floral disc—thought to have evolved from petals and sepals.

Fremont's Cottonwood with capsules and young leaves (TreeLib, J Morefield photo).

Mature leaves and bark, Fremont's Cottonwood (TreeLib).

These last photos are included in part to thank Blake and Nathan Willson for their wonderful Tree Library website—"a digital platform for teaching and studying trees with a focus on promoting awareness and understanding of trees and their global importance to the environment."

Fremont's Cottonwood, Rio Grande, New Mexico. "Trees are our silent partners, sensing us as we move about, providing shelter, offering us beauty, and nurturing and protecting the earth." (TreeLib)

Addendum, 23 Oct 2024. Posch, BC, et al. (2024) found Populus fremontii to be super efficient at leaf cooling (via transpiration) even when temperatures exceed 48 °C (118º F)! But water must be available. Even a minor disruption in availability will shut down cooling, causing leaves to overheat. See Intensive leaf cooling promotes tree survival during a record heatwave. 

https://doi.org/10.1073/pnas.2408583121

Sources, in addition to links in post

Eckenwalder, JE. 1977. North American cottonwoods (Populus, Salicaceae) of sections Abaso and Aigeiros. J. Arnold Arboretum 58:193–208 [P. fremontii p. 198-200] BHL.

Fremont, JC. 1887. Memoirs of my life: including in the narrative five journeys of western exploration during the years 1842, 1843-4, 1845-6-7, 1848-9, 1853-4 Internet Archive.

Sargent, CS. 1896. The silva of North America: a description of the trees which grow naturally in North America exclusive of Mexico. Vol. 9 (P. fremontii p.183 ...) BHL.

Watson, S. 1875. Revision of the genus Ceanothus, and descriptions of new plants ... Proceedings American Academy of Arts & Sciences. Vol. 10 (P. fremontii p. 350) BHL.

This is my October contribution to the monthly gathering of Tree Followers, kindly hosted by The Squirrelbasket.

South Dakota Trees: Black Walnut

Black Walnut with spring leaves—its "yearly trick of looking new" (Philip Larkin, The Trees). Union Grove State Park, South Dakota.

Walnuts from a previous year, still unopened. Is extreme toughness adaptive?

Continuing my quest to get to know South Dakota's trees, I chose Black Walnut (Juglans nigra) for this month's tree-following. It's native to the state but barely, probably just in the far east. This is another deciduous hardwood that's common in the midwestern and eastern USA, but rare in South Dakota. Humans have long contributed to the spread of these species, so it can be difficult to pin down their "native" range.

Black Walnut trees can reach 150 ft in height. On open sites the crown is large and rounded. In forested habitat it's smaller, atop a tall mostly unbranched trunk. 

Black Walnut is popular in landscaping; Victoria, British Columbia (TreeLib).

Juglans nigra was once "a dominant and majestic canopy species of primeval midwestern and southeastern forests." But with clearing for agriculture, and harvest for railroad ties, gunstocks, log cabins, furniture, ship-building and more, it became much less common (GoBotany). The venerable giants—to 6 or 7 ft in diameter—are gone. Even so, Black Walnut wood is widely available and quite popular—prized for its dark grain (more information at The Wood Database).

Black Walnut in cross section; photo by Roger Culos.

Black Walnut bowl and photo by Joe Nestlerode.

Juglans nigra leaves are alternate, but often cluster at branch tips and appear whorled (MWI).

Black Walnut usually can be recognized by its leaves, which are long (to 6 dm) and pinnately compound with 8–23 leaflets (terminal one often reduced or lacking). Leaflets are lanceolate, to 15 cm in length, and have serrate margins.

Carl Linnaeus, who named and described the species in 1753, included leaf features in the polynomial name: Juglans foliolis lanceolatis argute serratis—a Juglans with lanceolate leaves with serrate margins. Did Linnaeus mistake leaflets for leaves? Perhaps there was no such distinction in his day.

Black Walnut in Linnaeus's Species Plantarum (1753). Note "nigra" in fine print on right.

In the image above, "nigra", "alba" and "regia" on the page margin hint at a revolution underway. The long descriptive polynomial names were being replaced with binomials (still in use). Species Plantarum is considered the first major botanical work to use binomials consistently. This is where Juglans foliolis lanceolatis argute serratis; exterioribus minoribus became Juglans nigra L. (L. refers to Linnaeus, the authority).

Juglans nigra L. from The Linnaean Herbarium, with permission. Linnaeus did not cite a type specimen in his description, so this one was selected as the lectotype (Reveal et al. 1987).

Like all walnut species, Juglans nigra has unisexual flowers and trees bear flowers of both sexes (i.e., are monoecious). Flowers are inconspicuous—small, yellowish to greenish, with no petals and only tiny sepals. Males form catkins (elongate pendulous clusters) to 10 cm long, with numerous flowers. Female flowers occur in little clusters of 1–4 in leaf axils (where the leaf stem attaches to the branch).

Catkins of male flowers, each with numerous stamens (MWI).

Three female flowers in a leaf axil, each with 2 feathery stigmas (TreeLib).

A female flower has a single pistil. With fertilization, it matures to become ... well ... that depends on whom you ask.

 Juglans nigra fruit, fibrous covering partly removed. Is this a nut? drupe? pseudodrupe? (Plant Image Library)

In their treatments of the Black Walnut, early botanists just described the fruit. The first to do so may have been Mark Catesby, an English naturalist who studied the flora and fauna of the American colonies. In his Natural History of Carolina, Florida and the Bahama Islands (1731) he wrote:

"The thickness of the inner shell requires a hammer to break it. The outer shell is very thick and rough on the outside. The kernels are very oily and rank tasted; yet, when laid by some months are eat by Indians, squirrels, etc." [Kernels are seeds, also called nutmeats.]

Illustrations in Catesby's book "were etched by the author"; plants and animals often were paired, e.g., Black Walnut and American Redstart (relative sizes of fruits and bird are correct) (BHL).

In his 1819 American Sylva, François-André Michaux (featured in this post) provided a bit more detail:

"The husk is thick, and ... when ripe it softens and gradually decays. The nut is hard, somewhat compressed at the sides, and sulcated [with narrow grooves]. The kernel, which is divided by firm ligneous partitions, is of a sweet and agreeable taste, though inferior to that of the European Walnut." 

Black Walnut, by the great botanical illustrator Pierre-Joseph Redouté, in Michaux 1819 (BHL). Male flowers upper left; fruit with green husk lower right next to brown nut.

However it wasn't long before botanists were attempting to assign fruits to defined types. Asa Gray, the eminent Harvard professor of botany, included a system of fruit types in his 1868 Lessons in Botany and Vegetable Physiology. Now 156 years later, it's still in use because botanists haven't come up with anything better. This is not for lack of trying (see Judd et al. 2002, for example).

So what did Professor Gray call the walnut? Well, actually ... he hedged!! In his New Manual of Botany. A handbook of the flowering plants (1908) he called it a "a kind of dry drupe". Dry drupe? But Professor, you defined a drupe as having a fleshy outer part and hard inner part, both derived from the pistil. You provided the cherry, plum, and peach as familiar examples.

As Professor Gray demonstrated, the walnut is not easily categorized. And it's not alone—more than a few fruits confound us in this way.

Parts of a walnut: husk, shell (nut), nutmeat (seed). Wild Harvests.

Some botanists take a strict approach: a fruit must develop from a pistil. This is where the fruit of the walnut—specifically the husk—causes problems. "[It] superficially resembles a drupe, with a hard 'stone' surrounded by a soft, often fleshy husk. The husk, however, is not part of the fruit wall (it develops from the involucre and calyx), and the fruit is actually a nut." (Juglandaceae in Flora of North America).

The Wikipedia Walnuts article mostly agrees, but calls them "accessory fruit because the outer covering [husk] of the fruit is technically an involucre and thus not morphologically part of the carpel [pistil]; this means it cannot be a drupe but is instead a drupe-like nut."

Other botanists are more broad-minded. A fruit with a (relatively) soft outer part and hard inner part can be a drupe, no matter the origins of the parts. Some avoid the controversy altogether by calling the walnut fruit a "drupe or nut" or explaining that it's a nut "but some experts call it a drupe."

That's more than enough discussion of disputed terminology. Let's turn now to something for which there is widespread and probably unanimous agreement. The Black Walnut is a tough nut to crack, in fact one of the toughest!

Cracking a Black Walnut Appalachian style (Blind Pig & the Acorn).

Black Walnut nutmeats are available commercially thanks to "high-tech" processing (video here). But there are alternatives. For those who aspire to collect, clean and crack Black Walnuts themselves, a wealth of helpful information is available online. The most common approach is a hammer, as Mark Catesby recommended nearly three centuries ago. Iowa State University Extension and Outreach explains:

"The hammer method involves placing the nut, pointed end up, on a hard surface and striking the point with the hammer until it weakens and splits into sections along its axis ... shattering of the kernels is often a problem. Shattering can be reduced by soaking the nuts in water for 1 or 2 hours before cracking. The soaking process allows the kernels to absorb enough moisture to become somewhat flexible, resulting in larger kernel pieces."

"Once split, use a pick or plier to remove the kernels inside." (ISU Extension & Outreach)

And for those of us with less patience, John Sankey includes a variety of tools on his Black Walnut Crackers webpage, with tips on use.

The Duke Black Walnut Nutcracker is highly-recommended ($78 on Amazon).

Sources, in addition to links in post

Catesby, M. 1731. Natural history of Carolina, Florida and the Bahama Islands. Volume 1 (Black Walnut p 67). "The illustrations were etched by the author from his own drawings and hand colored under his direction." Catesby also paid for printing. BHL

Gray, A. 1868. Gray's lessons in botany and vegetable physiology. NY: Ivison, Blakeman, Taylor & Co. (BHL).

Gray, A. Circa 1908. Gray's new manual of botany. A handbook of the flowering plants and ferns of the central and northeastern United States and adjacent Canada. NY: American Book Co. BHL

Judd, WS, et al. 2002. Plant Systematics, 2nd ed. Sinauer Associates, Inc.

Linnaeus, Carl. 1753. Species Plantarum 2, p. 997. BHL.

Michaux, F-A. 1819. The North American sylva, or A description of the forest trees of the United States, Canada and Nova Scotia. BHL

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

Reveal, JL, et al. 1987. On the identities of Maryland plants mentioned in the first two editions of Linnaeus' Species plantarum. Huntia 7:209–246. PDF