The Oddest Plant in the Garden: the Ginkgo Tree (Ginkgo biloba)

Evolution? I'm a huge fan. Otherwise I'd be floating around in the ocean, bored out of my mind (to the extent that a single-celled organism would have a mind), waiting for something to do. Instead, I can write a blog post, or go eat oyakodon, or watch the next episode of The Traitors, or pat my dog, all of which brings me joy.

And because I adore classification (no, really), I appreciate that thoughtful people before me have organized the plant and animal kingdoms, and rather than sorting them by colour, or utility, or shape, they've done it by How-Related-To-One-Another-Everything-Is, which works for me. At some point there was an ancestor to plants and animals, but they diverged so early on that we pop them into different kingdoms, where you will also find (each in their own realm) the Fungi, the Protists (a type of algae), and the Bacteria.

Looking at plants, we find experts further divide these into Divisions, Class, Order, Family, Genus, and finally species. Sometimes they get excited and toss in a "sub-" for extra granularity between tiers. The divisions are—well, experts will argue about how exactly to separate things, but roughly they are Liverworts, Hornworts, Mosses, Club Mosses (woo, party!), Ferns, Cycads, Conifers, Ginkgos, Gnetophytes, and Flowering Plants.

These early distinctions are important. We won't expect a fern to flower, because it's not one of the (very, very many, it's a successful clade) flowering plants. Today's featured plant is the Ginkgo, and it too doesn't flower. It's considered a Gymnosperm, which is a grouping that includes Cycads (they look like palm trees, but aren't), Conifers (you know these, Firs, Pines, etc.), and plants in the Gnetophyta division (the weird relatives you barely know and don't invite for holidays). So it's slightly more related to those than to anything else, but still very much on its own, in its own division.

And yes, I mean "on its own." For while there are lots of cycads, heaps of conifers, and about seventy species' worth of gnetophytes, there's only one species in the entire Ginkgo Division: the Ginkgo biloba. That's it. It has no other near relations. Which is why, from a certain point-of-view, I think of this tree as the strangest thing in my garden. It's the plant that, at the highest level, is the most unlike other plants.

Sure, it looks like a tree, but "tree" is really just a catch-all term for anything that shape that has evolved to counter gravity with some nifty tricks of its own. It doesn't have fruit, since fruit comes from flowering plants only, it doesn't have a nut, because nuts are also only found in flowering plants. It doesn't grow a cone, that's for conifers only. Instead it grows a seed surrounded by a fleshy covering, and we don't have a common name for it, because we didn't (in the west) know about ginkgo seeds until the 17th century.

And this is how that happened. A westerner (Engelbert Kaempfer) was a German naturalst who travelled to Japan at a time when Japan was closed to the general public, much like between 2020 and 2022. During those years the only westerners encountered were the Dutch, who (through the Dutch East India Company) were allowed to trade with Japan from their outpost in Dejima, a man-made island near Nagasaki. This island was not considered Japanese soil, hence, the Dutch could reside there without technically entering the country.

Despite this prohibition, the Shogun did require the Dutch chief to journey to Edo every year (later they adjusted it to only every four years). To ensure that they would never touch Japanese soil, the chief (and his retinue) would stand on carpets when not actively travelling, and their travel was made via palanquin (norimon, in Japanese). These closed boxes were suspended from long wooden poles, and the poles rested on the shoulders of porters: typically four to eight carriers, depending on the dignity (or weight) of the occupant.

Kaempfer was the chief's official physician at this time, so he went along for the ride. The journey was about 1,000 kilometers (one way), with 53 stations along the way to swap out porters for fresh ones. And along the way, Kaempfer saw his first Ginkgo tree. And he drew a picture of it (well, part of it):

You can see it labelled: 銀杏. These characters are known as kanji in Japanese, and are dervied from (and usually the same as) Chinese characters, since the Chinese introduced their writing system to Japan about 1500 years ago. The adoption of a writing system caused some growing pains: the Chinese would point out the pronunciation of their characters, and the Japanese would politely (I assume) point out that they already had a language, thank you very much, and would go on using their own pronunciation, despite the Chinese' best efforts. A compromise was reached where common individual words (e.g. strawberry, or today) would use the Japanese pronunciation (known as kunyomi) , but new compound words (e.g. medical school) would use the Chinese pronunciation (known as onyomi). Much like English vis-a-vis French and Latin, the home-grown words seem commonplace, and the foreign words have an air of authority and legalese about them.

So the ginkgo is called "ichou" in Japanese, but the characters refer to the "Silver Apricot," its name in most asian cultures. Silver's onyomi pronunciation is "gin" (as in Ginza, where the silver sits, i.e. the mint), and Apricot is "kyo", hence "ginkyo". In his notes, Kaempfer wrote "Ginkgo" because his assistant had a Nagasaki accent, making the "y" a more nasal sound, which Kaempger misinterpreted as a "g".

The tree is notable for a few other reasons: it comes in male and female forms separately (which is not unheard of, but most plants are hermaphroditic—the plant term is monoecious). The males grow catkin-like structures to release their pollen, and the female receives it and grows the fleshy-covered-not-a-nut. This fleshy covering has a distinctive scent when it rots, a pungent aroma conjuring up notes of parmesan and vomit, and you often realise you're walking under a female gingko tree in the Autumn by smell rather than sight.

The latin species' name biloba comes from the tendency of the leaves to have two lobes. The popular Ginkgo extract is primarily made from these dried green leaves. The seeds themselves are slightly toxic, but consumable in small quantities, and are a popular treat when in season. It's a hardy and robust tree: it managed to survive the Hiroshima atomic bomb, or at least its roots did, and the tree eventually grew back. Some trees are thought to be over 3,000 years old.

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Notes and Links

Engelbert Kaempfer (1651–1716) - author of Amoenitatum Exoticarum, a foundational text in Western botany

Dejima - fan-shaped artificial island

Oyakodon - yummy chicken and egg (and rice bowl) dish

Hibakujumoku - trees that survived the atomic bombing