Out of time - the Osage Orange

But people – those whose hunting had emptied almost all of the globe’s continents of their most majestic inhabitants – took on the task of spreading the seed, because many of these plants had attributes that humans found desirable. A study three years ago examined why it is that the Honey Locust (Gleditsia triacanthos), a tree that prefers rocky uplands and xeric fields is inexplicably found in mesic riverine corridors and floodplains. The premise, based on oral history, was that indigenous people – for whom the tree had important medicinal, cultural and spiritual meaning – were responsible for this counter-intuitive distribution.

The study was able to correlate pre-historic Cherokee settlement patterns with Honey Locust distribution. The conclusion: where a species is found but is not necessarily in its ecological niche, it can persist in unsuitable habitat for centuries. This depends more on its dispersal partner than on its own preferred habitat requirements for continued survival.

The Osage Orange (Maclura pomifera) was prized by indigenous people for wood that was hard and rot-resistant (used for making bows, which led to its being named bois d’arc by French trappers). The same characteristics – along with ferocious thorns – led to its adoption by settlers as a vigorous hedging plant for confining livestock. Remnants of such hedgerows remain in south-western Ontario. Its current distribution in North America is from coast to coast.

2022 note - I have trees on offer - see plant list. 

Which brings me to my seedlings. Last November, a friend who works in the GTA said a co-worker had come into the possession of two Osage Orange fruits, and would I like one? Yes, yes, yes! I replied. The fruit was duly delivered – a lovely large knobbly pale green globe.

I set about researching how to treat the seed, and found a wealth of contradictory information online. In the end, the method that worked was the simplest one. I left the fruit all winter in an unheated room, half settled into a bucketful of soil, covered with some mesh to stop theft by mice that apparently enjoy the seeds (ingestion of the seeds by rodents is not part of the tree’s dispersal strategy, because they get chewed up and digested. They need to pass through a digestive system cleaned but unharmed and be deposited in a pile of dung miles away from their parent plant). From time to time I added snow.

In February, I dumped the rotten fruit in a bucket of water. I washed the seeds out – 206 of them – and planted some in a soil mix. They started germinating a couple of weeks later and now, here we are. Thirty hopeful young trees depending on me for a bright future. The trouble is, I think it’s too cold for them here. Huronia is a hardiness zone cooler than south-western Ontario where the seed came from (I assumed - see postscript below). So I need to find customers in locations where they will reliably survive the winter.*

Perfect plan: the North American Native Plant Society (NANPS) has some sales coming up. I offered them my seedlings – and was declined. NANPS uses NatureServe as a guide when deciding 'what is native' and NatureServe lists Osage Orange as native to Texas, likely to Oklahoma, Arkansas and Louisiana and naturalized elsewhere. (Naturalized means that it’s living wild in an area, but isn’t originally from there.)

I don’t contest the decision, but it raises interesting questions about scientific rulings that affect far more than a local plant sale - they affect what plants and animals are allowed or banned in official wilderness areas across the landscape. Think of efforts in the U.S. and Canada to remove wild horses or burros from government-managed lands because they are alien – when in fact the modern horse is descended from creatures of the same genus that migrated to Eurasia but became extinct in America.

My question is whether we err in confining ourselves to the historical record, the last 500 years, in deciding what's native and what isn't, without looking at pre-history, indigenous knowledge or the fossil record. Here’s what Connie Barlow writes in The Ghosts of Evolution – Nonsensical Fruit, Missing Partners and Other Ecological Anachronisms (2000): "The native range of maclura prior to the arrival of Europeans is thought to have been the Red River region where Arkansas, Texas and Oklahoma join. This is a very restricted and spotty range, since fossils indicate that during interglacial episodes of the Pleistocene epoch the tree lived as far north as southern Ontario."

If Osage Orange lived this far north more than 10,000 years ago, who are we to say that it doesn’t belong in Ontario now? The fact that its dispersers are extinct doesn't mean the plant isn't "native." But there are other factors to be considered. For instance, does it fit into our present native ecosystems or would it cause degradation? The answer, for the Osage Orange, from the evidence of southwestern Ontario, is that it causes no harm (except to anyone who might be standing under a female tree when the fruits are obeying gravity in late autumn or in winter). The ecosystem is of course missing the tree's partners, wild members of the elephant, camel, horse and other families that were once native to these shores - but that’s another matter.

Still, it is something geoscientist Paul S. Martin worked all his life to address. Until his death in 2010 he was a leading proponent of the idea that modern ecology has been confined by the "Columbian curtain" to the last 500 years. We rely on Europeans’ observations of this continent at the time of “discovery” to determine what belongs where, leading to a very imperfect knoweldge of the true nature of the American wilderness.

“We are obsessively focused on protecting what we have and utterly unaware of what we have lost and therefore what we might restore," he wrote in Twilight of the Mammoths - Ice Age Extinctions and the Rewilding of America (2005).

Alas, far from broadening our minds with regard to opportunities for restoration, it appears that we are abandoning what we have. Last week brought sad tidings, that we are on the verge of losing another recently familiar garden companion, the American Bumblebee.

This came in the wake of notification that Ontario’s inadequate Endangered Species Act is about to be further weakened. We are a wealthy province, but it seems we won’t make an effort for creatures that are struggling to make a living in a world in which their habitat and resources are being ever more depleted. If we can’t do it, what hope is there for the Sumatran Elephant or the Leatherback Turtle?

And further bad news – of cuts to Ontario’s libraries that will end the inter-library loan system and thus, for me, access to a world of research that helps deepen my understanding of what I should be doing in my small patch of Earth.

There’s lots to do. How did those weeds spring up so fast under the snow that hasn't even yet completely left our area? 

Here are some timely thoughts from previous years:

- When the leaves of the dogwood are the size of a squirrel’s ear, it is time to plant.  
- Take it easy with the 'cleanup’

Happy Earth Day! 

* Postscript 23/04/19: I didn't think to inquire, when I first got this seed, where it came from. I just assumed it was from the area of Ontario where I had observed the tree in the past. I am now advised that it came from a hedgerow in or near Caledon – possible the most northerly location for this species. This increases the chance of success for my plan to overwinter some of my trees here north of Barrie, ON in 2019-20.

* Post Postscript 20/03/22: Two of these Osage Orange trees have survived two winters in Simcoe County.