24 October 2017

"Hedge apples" may "remember" the megafauna


An interesting post today at American Forests muses about the "hedge apple"/"Osage orange"/"monkeyball" (Maclura pomifera):
Consider the fruit of the Osage-orange, named after the Osage Indians associated with its range. In the fall, Osage-orange trees hang heavy with bright green, bumpy spheres the size of softballs, full of seeds and an unpalatable milky latex. They soon fall to the ground, where they rot, unused, unless a child decides to test their ballistic properties.

Trees that make such fleshy fruits do so to entice animals to eat them, along with the seeds they contain. The seeds pass through the animal and are deposited, with natural fertilizer, away from the shade and roots of the parent tree where they are more likely to germinate. But no native animal eats Osage-orange fruits. So, what are they for? The same question could be asked of the large seed pods of the honeylocust and the Kentucky coffeetree...

In terms of evolutionary time, the difference between 13,000 years ago and now is like the difference between Friday, December 31, 1999 and Saturday, January 1, 2000. We may assign those two days to different centuries or millennia, but they are still part of the same week. Likewise, all the animals and plants of 13,000 years ago belong just as much in the present. In fact, they still live in the present, with just one major exception: most of the big and fierce animals are now gone...

Now let’s return to the forlorn fruit of the Osage orange. Nothing today eats it. Once it drops from the tree, all of them on a given tree practically in unison, the only way it moves is to roll downhill or float in flood waters. Why would you evolve such an over-engineered, energetically expensive fruit if gravity and water are your only dispersers, and you like to grow on higher ground? You wouldn’t. Unless you expected it to be eaten by mammoths or ground-sloths...

It’s true that such adaptations are now anachronistic; they have lost their relevance. But the trees have been slow to catch on; a natural consequence of the pace of evolution. For a tree that lives, say, 250 years, 13,000 years represents only 52 generations. In an evolutionary sense, the trees don’t yet realize that the megafauna are gone.
More at the link, and a big hat tip to Quigley's Cabinet for the via.

Reposted from 2013 because when I walked the Arboretum this past week, the ground was littered with "hedge apples" -


And not a ground sloth in sight.

15 comments:

  1. I believe the same is true for why no other extant animals eat mango and avocados. Thanks to extinct megafauna, we can now enjoy these giant delicious fruits. Not sure how likely it is for some other animal to come around and help out the Osage orange (or others) in the next hundred thousand years.

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    1. There are animals that eat mangos and avocados, but they're large fruits which probably were eaten by megafauna as a target group, since the smaller animals don't cart them far.

      Except humans. So avocados and mangos are not at all threatened, they found an animal to pick up the slack.

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  2. the first time i ever saw an osage orange was on the day i went to visit the grave of stonewall jackson's arm.

    so kind of surreal all around.

    they hurt when the fall on you, but they smell pretty.

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    1. That second link with the Attenborough video is brilliant. And it makes an important point about the supposedly sad demise of the ophrys apifera, which is that it didn't give its bees a reward. Rather, it demanded effort from them and caused them to waste their resources for its own selfish benefit. If it had, instead, offered up some nectar, its pollen couriers would have benefitted from their pollination work and both species would have thrived.

      It's almost as if there's a lesson in there for us...

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  4. My Michigan squirrels eat osage oranges. I collect them in November to feed them all winter. They must first freeze and then thaw, and then I roll them out into the yard, and the squirrels go crazy for them. It's fun to watch a squirrel try to carry one up a tree in its teeth, because often the weight is too great and he falls down. When they eat them on the ground they shred them furiously into yellow piles, eating some select portion of them.

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  5. The seeds are edible, but its a huge mess and waste of time. Squirrels seem to like them (as reported above).

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  6. Once a year, we gather some up, and strategically place them on paper plates around our house (usually down beside the toilet, or on top of our refrigerator, etc). Common wisdom is that they ward off spiders. I'm not sure if this works, but as they rot, they don't give off a smell noticeable to humans.

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    1. I'm just curious - how do they "evolve" after you bring them in? Do they disintegrate into a gooey slime, or (more likely I suppose) desiccate into a dry shriveled mass? Or other?

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  7. We had hedge apples along the fencerow of our pasture when I was growing up and some of our horses liked to eat them.

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  8. One year the hedge tree behind my house had a bumper crop, & I googled uses for the offensive ballistic missiles (they made a terrific noise falling on the metal roof!). I read that they repel spiders, so, being distressed at the proliferance of such, I lined the inside of the garage with them, and lo and behold, spiders out there were gone! Lasted a couple of years. It was time to replenish them this year, so I've done so. I pick them up soon after they fall, before they start rotting, & while they to deteriorate over time, they do the job of keeping the garage spider-free.

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  9. The funny thing to me is that some people deliberately grow Osage oranges in spite of the fruits being a tremendous mess.
    That reminds me of a funny idea among orchid collectors: maybe rare and fragile orchids have figured out that the way to survive is to appeal to a large and widespread species that will care for and cultivate them.

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    1. Yep. Corn (Maize) is one of the most successful species on the planet precisely because it tricked a species (us) into cultivating it all over the planet.

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  10. And Kentucky Coffee Bean tree! I have one in front of our house. Last to leaf out in the spring, first to lose all leaves in the fall. The pods are rather appealing.

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  11. Being born and raised in Kansas where osage orange, hedge apple was planted for wind breaks and shelter belts and doing a lot of hunting I know for a fact that squirrels eat the fruit. They have been used by farmers for generations to keep spiders out basements and root cellars. If you ever shoot and cook and eat squirrels feeding on a lot of osage "apples" you won't do it again. Some folks have an allergy to osage orange sawdust. One bowyer friend has to go to the hospital if exposed to it. One book called the Natural History of Trees has a chapter on osage orange trees. Very interesting reading with unusual facts about the versatile and tough tree.

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