The Incredible Edible Fig

What if I told you I knew of an incredible story containing equal parts ancient history, coevolution, botany, devotion, exotic travel, mystery, symbiotic relationships, manipulation, love and death?

You’d put it at the top of your summer reading list, right? Well, I do. But you don’t need to rush off to your local library to grab a copy; just spend a bit of time under the shade of a fig tree. You’ll find the story, there, hanging from its branches.

Have you ever smelled the alluring scent of a fig tree in bloom? Well, no. You haven’t. That’s because they’re located--hundreds of them--within the green “fruit”, (technically a synconium). But the fig wasp can, and that’s all that matters.

You see, the female fig wasp is the fig’s sole pollinator. There are 1300-2600 suspected species in the world, and each one has coevolved and maintains a mutual relationship with its specific host fig tree. Hardly visible, they’re tiny enough to squeeze through the eye of a needle, which is crucial since the only entrance into the fig’s secret garden is barely passible. And once she’s in, there’s no way out.

The cozy symbiotic relationship between the fig and fig wasp, in nature, is legendary. It’s an I’ll-scratch-your-back-if-you-scratch-mine sort of relationship. The fig allows the female wasp to lay her eggs within and agrees to host and feed her larvae, if she in turn brings pollen from a neighboring fig tree along with her, thus providing pollination and subsequent seed production for the fig. It’s a win win! 

The process is pretty dramatic, really. There are two types of fig trees involved. The inedible caprifig sports inflorescences with both male and female flowers, the female flowers hosting a nursery of wasp larvae within. And as part of the genetic code developed over millions of years, the cycle begins with the male wasps emerging from their sacks first. 

The male wasps’ life has three purposes, all of which are completed without ever leaving the interior of the fig. Immediately after emerging, they sever the tall anthers, thus making it easier for the females to collect pollen. Next, they tunnel an exit route for the ladies. Once completed, they mate with them and then...well, they die. Yep, they never even see the light of day. 

The female wasps’ mission, however, is just beginning. Carrying fertilized eggs, they need to find a fig in which to deposit them. And fast! But before making their way out of the pre-carved tunnel, they collect pollen from the fig’s male flowers, their gift to the soon-to-be-visited fig, and pack it tightly into specialized pollen-carrying sacs. 

Out of their birth fig, they fly about, honing in on volatiles released by female fig flowers, signaling that they are currently receptive to the wasps and their precious gift of pollen. 

Instinctively, the female locates the tiny opening at the apex of the fig and squeeeeeezes her tiny, made-for-the-job body through. It’s such a tight fit, she loses her wings in the process. But, it doesn’t matter; she won’t need them anymore. After all, she’s inside and her pollen-delivering, egg-laying mission is almost complete.

However, there’s a twist. 

Oftentimes, one mistakingly finds herself inside the fig of an edible fruit tree, which is very different than the figs on the inedible caprifig tree. Rather than containing both male and female flowers within, the edible fig has only female flowers. But there’s another, more significant, difference. The flower’s style, the tube which leads to the ovary, her intended egg-depositing site, is much much longer than her ovipositor. Frantically, she tries each flower, looking for one in which she can reach the ovary. But it’s a lost cause; they’re all long-styled flowers. Ultimately, she dies of exhaustion...but not before fertilizing the fig’s flowers. 

Appalled at the injustice? The unfairness? The blatant manipulation? Don’t be. More than enough wasps find their way into the fig of a caprifig tree, thus successfully completing their lifecycle. Besides, without this trickery, you’d be eating figs full of wasp larvae instead of flavor-lending seeds! 

So, you may be wondering if, when feasting on figs, you’re also feasting on dead, childless wasp bits. Well, no. Not really, anyway. After the wasp dies, her body is essentially dissolved by special enzymes secreted by the fig. It’s the perfect crime!

Now, before some of you, in a swift gesture of disgust, take a chainsaw to your own fig tree, take a breather. The common fig, like those in our home gardens throughout most of the United States, are parthenocarpic. That is, they’re seedless, and produce fruit without being fertilized by a pollinator. And good thing too, since there aren’t any native fig wasps, in our area, to carry out the gritty business of sexual reproduction.

This parthenocarpic trait is a mutation in nature. And while normally disadvantageous to a plant species’ overall diversity and geographic dispersal, it’s a whole different story when human’s interfere. 

In fact, carbonized, seedless figs, recently discovered in the Lower Jordan Valley, suggests that parthenocarpic fig cultivation was taking place 11,400 years ago. (This is pre-pottery and 1000 years before the cultivation of cereals, like wheat and barley!) This means, Neolithic civilizations recognized, valued and exploited this mutation through means of branch cuttings (a means of propagation easily carried out with your own fig tree cuttings). 

No longer relying solely on pollination via the fig wasps, tree cultivation spread far and wide. Much further and wider than would’ve been possible by the fig’s natural means of sexual reproduction. Turns out, not a disadvantageous mutation, after all!

So, the next time you relish in the luscious flesh of a homegrown fig, stop to think of the countless root-steps the fig tree has taken through the millennium and across continents to end up in your backyard. 

Ancient history has never tasted so good.

*For quidelines on how to grow figs and which types are best for our area, see this publication from The College of Agriculture and Environmental Sciences. 

*For an absolutely amazing documentary on the sycamore fig tree and the massive ecosystem it supports, click here. It's an hour very well spent. I promise.