Watoga Trail Report

An impressive array of thorns on this honey locust. Note the many lenticels on the bark that allow for gas exchange between the air and the interior of the tree.

Ken Springer
Watoga Park Foundation

A honey of a tree
An ode to exquisite adaptation

I am drawn to the unusual, the oddities, those things we pass by every day and never notice. Throughout my years in school, I often found myself in the company of the outcasts. I considered those young folks to be far more interesting than the “normal” kids who relentlessly harassed them.  

Even today, I find that my human friends are generally cut from a special cloth kept under the counter, not the mass-produced stuff. So it’s no surprise that I keep my eyes and heart open for the same things in nature.

Nature has its own outcasts. Just consider the word “weed.” The very name reeks of negativity. How is it that we can pass judgment on a vast range of plants, or humans for that matter, without fully exploring their potential?

Within the realm of possibility there is a plant out there deemed noxious, yet harboring a chemical compound that can stop the coronavirus on contact.

This squirrel is adept at scurrying around the multitude of thorns on the honey locust tree. Seedpods containing the sweet goo can be seen in the foreground. K. Springer photos

Just look at the long list of the health benefits of dandelion root. Yet, there are millions of suburban garages fully equipped with an arsenal of gadgets and chemicals designed to eradicate that single species of plant.

Standing some 70 feet tall along the Greenbrier River in Seebert is a magnificent honey locust tree. The old gentleman has one foot in the river and the other on dry land. The trunk fairly bristles with clumps of enormous thorns, some measuring up to eight inches in length and are alleged to be sharp enough to have been used as nails in earlier days.

While strolling by this tree last week, I spotted a squirrel sitting calmly upon a horizontal branch about eight feet off the ground. The squirrel allowed me to take several pictures before scurrying up the trunk and out of sight.

Expecting that the squirrel would be immediately shish-kabobbed on the sharp thorns when she bolted, I was awestruck at how she navigated around these formidable impediments without injury and without slowing down.

This event drew my full attention to the tree, and in doing so, I gained a whole new perspective on the tree’s defense mechanism. It would be a foolish predator who would give chase to a squirrel on a honey locust tree.

Should a porcupine find itself waddling down the Greenbrier River Trail one day, I can well imagine that the sight of the locust tree would stop her in her tracks. She may even think, “Now there’s a fellow I could go for.”

Other than the squirrel, there are likely no other takers for a stroll up a tree trunk festooned with bayonets. So how did the honey locust become so ably equipped to repel most predators?

Enter the Mastodon.

But before we get to that giant herbivore we have to make a quick stop in Africa and visit another giant herbivore, the elephant.

The African elephant loves to munch on the sweet seedpods and bark of acacia trees, which are related to the honey locust. Both species, locusts and acacias, are in the legume family – both are related to those pinto beans we love to eat with ramps and cornbread here in Appalachia.

Being eaten by elephants is obviously not in the best interest of the acacia trees. Over millions of years, the tree developed thorns and spines very similar to the modern honey locust. This defensive mechanism makes the acacia far less appealing to the elephants and further ensures the plant’s long-term survival.

OK, now back to the giant hairy mastodons that flourished for millions of years, only to become extinct some 11,000 years ago. Why they became extinct is an excellent topic for a future Watoga Trail Report, but for now, we will focus on the relationship of the mastodon with the honey locust.

Paleobiologists have yet to find indisputable proof but theorize that the honey locust tree co-evolved with the mastodon in North America. There is evidence from petrified poop, called coprolites, that the great herbivores found the seedpods appetizing. *

So it does make sense that the honey locust, like the acacias, would have developed impressive armament to discourage the mastodon’s gustatory activities.

Some sources claim that a honey locust thorn can be driven through a two-by-four. My experiments with a dozen of the thorns did not result in being able to pound them more than 5/8 inch into a pine two-by-two.

Perhaps they would have to be heat hardened first to be able to puncture two inches of wood. However, the thorns are sharp and exceptionally sturdy.

Evolutionary response is exquisitely proportionate to the threat, so at the very least, the thorns are capable of piercing the tongue and soft palate of the mastodon. This should elicit enough pain to discourage the herbivore from browsing on the honey locust.

The honey locust, also known as sweet locust, gets its name from the sweet pulp found in the bean pod, which has a sugar content of 30%. Foraging publications compare the greenish-yellow goo to everything from honey to gooseberry jam.

I have tried it and will reserve judgment since my thoughts on its flavor are not even remotely comparable to the foraging sources. But, I can see where this treacly sweet ooze would be attractive to many animal species in search of carbohydrates.

The honey locust cannot take credit for the popularity of the sublime locust honey. (I do apologize if you had to read that sentence twice.) Nectar from the black locust flowers is gathered by bees to produce this nearly transparent and floral honey.

Bees pretty much ignore the tiny greenish-yellow flowers of the honey locust.

The next time you visit the enchanting little village of Seebert, I urge you to park by Horner’s Corner and walk about 50 yards downstream, and you will find the large honey locust right on the shore of the Greenbrier River.

Situated just above the large locust and right beside the trail is a younger, though no less impressive, honey locust. This beautiful specimen is likely a descendent of the big tree since the big guy’s seedpods fall at the foot of the younger tree.

And while you are there, think of the great hairy mastodon, that at the end of the last ice age was well on his way to extinction. Think about how all living things, including humans, are in a perpetual struggle to survive as a species – just like that thorny old locust tree.

Oh yeah, and that squirrel who can find shelter in the honey locust’s thorny bosom.

Ken Springer

Author’s Note: I can personally attest to the fact that a honey locust thorn can pierce the sole of a boot and continue right up through and out the top of a human foot.

In 1971 deer were still a novelty in Ohio, where I was a park ranger. So, when a deer chased by dogs broke through the ice of Rocky Fork Lake on a late February day, we felt inclined to rescue it.

In short, the rescue involved wading around in the cold water where I stepped on the trunk of a submerged tree, driving a honey locust thorn right through my foot and missing all bones en route.

Somebody later told me that the Emergency Room staff of the Highland District Hospital talked about it for a week. I was glad that I could break the boredom for those ER docs on that otherwise bleak February afternoon so many years ago.

* The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms. Connie Barlow

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