island of trees: Is the fig a fruit, the banana a tree?

This week's Wednesday in the Woods Treewalk: Westmount Park, August 3, 5:30 pm - 7:30 pm, Meet in front of greenhouse, next to library. $15. Registration: bronwynchester@gmail.com/514-284-7384

This is one of several species of banana, Musa sp, found in the Montreal Botanical Gardens in the  Tropical Food Plants Greenhouse. (Sorry, the illustration of the details of the banana fruit and flower is missing until next. Wednesday. Illustration: Charles L'Heureux

 I have an apology to make. Two columns ago, I misled you into thinking that the fig is a fruit. It isn’t; it’s a synconium. What’s that?, you say. Well, a synconium is the name given to the casing in which a cluster of hundreds of fig flowers reside. So, you may be wondering how on earth those flowers are pollinated. As Mother Nature would have it, each fig species has its own species of wasp that manages to enter the synconium by a single entrance at the opposite end of the stem. The wasp lays her eggs in the female flower, inadvertently picks up some pollen on her body, from the male flower, then exits by the same hole and goes on to the next fig, and, potentially, pollinates the female flowers, then dies.

What, then, is the fruit of the fig? A tiny druplet of flesh with a seed in the middle. The fruit-enclosed seed, in fact, gives the fig its gritty texture.

But, where the common fig, Ficus carica, is concerned, the story is even more unusual. Some 11,000 years ago, peoples around the Mediterranean Sea began to domesticate a mutant fig, which required no pollination, and, therefore, no wasps. However, it did depend on humans for its continuity; to this very day, the common fig is propagated via cuttings rooted in soil.

The phenomenon of fruits produced asexually is known as parthenocarpy, meaning “virgin fruit,” according to Wikipedia. Another parthenocarpic fruit, even more popular than the fig, is the Cavendish banana, Musa acuminata, the more common of all bananas eaten in North America. Like the fig, the banana is one of the oldest plants in cultivation. Australian archaeologists believe it was first cultivated at least 7,000 years ago in Papua New Guinea. Those species of this multi-species genus of plants, however, would have been seed-bearing as most of the numerous species of Musa were in their original territory of the Indo-Malaysian region, stretching south to northern Australia. By 300 BC, the plant had made it to the Mediterranean from where it made its way farther south into the African continent.

It was the Portuguese who brought the plant in the 16^th century from West Africa to South America, which remains the leading area of banana/plantain production in the Americas, while India leads in Asia.

You may have noticed that I don’t call the banana plant, a tree and that’s because it isn’t. If you make your way out to the Tropical Food Plants Greenhouse at the Montreal Botanical Gardens, you will see why not. There’s no wood in the stem of these huge, herbaceous plants. The “trunk,” in fact is a cylinder of leaf sheafs, from the middle of which grows a single stem with a large, deep red, tapering bud, the size of small melon. As each bract (the individual leaf-like scale) of the bud lifts, a row of  flowers is exposed. The upper ones are male and don’t form fruit.

The lower ones, are female and, once exposed to the light, rapidly form a hand of tiny bananas. What’s harvested form plantations is the entire stem, full of dozens of hands of bananas. Once the fruiting is over, the stem dies and the tree sends up another shoot and the process is repeated.

I have to admit that understanding the reproduction of both the domestic fig and sweet banana, has been arduous and Stéphane Bailleul, one of the botanists at the gardens has been a great help. The sexuality of plants is complex, to say the least, in contrast to animal sexuality, but these two genuses are particularly complex and highly interwoven with human history and intervention.

What I suggest is that on the next stinking hot day, you venture out to the gardens and take refuge from the sun in the (slightly) cooler, green shade of the amazing plants in the Tropical Food Plants Greenhouse. Completely revamped a few years ago, this greenhouse is a treasure trove of beauty, perfume, and information on the trees and herbaceous plants that produce many of our daily staples. In addition to the spectacular banana plants, many of which are bearing fruit, you’ll find coffee trees, guava, citrus trees, avocados, the cinnamon trees and numerous other spice plants. And, of course, there’s a fig tucked away in the corner.

I’d also recommend you visit the potted fig trees behind the restaurant. One of them is thick with large, almost ripe fruit – oops, I mean synconiums, or is that synconia? -  while the others are just beginning to form directly on the trunk, so you be able to observe them at different stages of development. You’ll also get a good look at the leaf. Be sure to feel it, to know the soft pubescence (hairiness) of the leaf.