Mystery Plant! #761

John Nelson

Posted 2/7/24

By John Nelson

It’s so Fly-Day, Fly-Day Chinatown…
                                                                Yasuha, 1981

This song came out 40 years ago, or so, and of course I wasn’t “hip” enough then to quite understand what it was all about. It was a rather popular song, though, in a good many circles. And, indeed, it’s got a catchy bounce-along rhythm and accompanying melody line. (Listen to me…I don’t know what I’m talking about.)

But this song involves Chinatown, as in New York City, which is one of my favorite places to visit. Last time was a couple of years ago, and we were able to satisfy not only a magnificent dim-sum lunch requirement, but a need to see lots of, well, “really interesting” things. If you happen to be a botanist, as am I, you will find Chinatown a supremely “interesting” place. Take the little markets, for example.

(Photo by John Nelson.)

In these you will find all kinds of food items that you don’t usually run into at your local MegaLoMart. Some of the items hanging from the shelves are rather easily identifiable: the ducks and chickens, bereft of feathers. Then there is the seafood, strange things renderable into gourmet fare. A cooked octopus, a box holding live crabs. Bins with baubles, and those little cat toys, with the raised paw and mysterious smiles. Vegetables and fruits from unknown parts of the planet, both fresh and dried or in cans or jars, along with piles of spices and pastes, full of exotic flavors and aromas which you may never have even imagined.

Here’s something I found, offered in a plastic bin, along with a crypto-Latin sign indicating what it held: I had to do a bit of research on this one to figure it out.

The white, elongated wafers are the dried shavings of a plant native to China. The shavings come from an extensive rhizome (not a root, and not a tuber) which takes several years to develop below ground. A twining vine sprouts from the rhizome, high-climbing in a garden, with attractive heart-shaped leaves. The individual plants are either male or female, and of course it’s only the female vines which make seeds. And, the vines commonly produce small, gray-brown aerial tubers, only an inch or so long. These are easily capable of starting new plants once they fall from the vines.

The rhizomes have been used in China as a common food source for thousands of years. Rhizomes must be variously cooked in order to make them edible, but once cooked, are full of carbs and those other things. Additionally, these rhizomes are an important part of traditional folk medicine in eastern Asia, and of course, are easily available these days in Asian markets or specialty stores on-line.

This species has been imported widely around the world, including the USA…which brings me back to those little aerial tubers. Because of them the plants have escaped from gardens into natural settings, and this species is now an awful weed, yet another invasive, alien species capable of covering up the native plants. Give it a try in your kitchen…but not in your garden, please

[Answer: “Chinese yam,” Dioscorea polystachya]

John Nelson is the retired curator of the Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the Herbarium offers free plant identifications. For more information, visit or email

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