Earlier this week, on a hot and sunny morning, I wanted to find out what I would see if I stuck my head and my macro lens into the interior of a Catawba Grapevine, behind the broad leaves and long stems twisted throughout an old iron obelisk trellis in one corner of my garden. The Catawba Grapevine is one of two I planted years ago as an experiment; the other is a Concord Grapevine, growing in a four-foot tall ceramic pot, winding up and through the bars of a fan-shaped trellis. Neither one produces grapes any more, but the Catawba has been returning every year for four years, and the Concord has grown back each spring and summer for eight years. In their first couple of years they both produced grapes, though the grapes never matured beyond the size of a pea: birds loved the tiny grapes and it was common for me to see a flurry of wings and beaks jabbing at the grape clusters until they were picked clean.
Both vines continue to grow and develop new leaves, stems, and tendrils until cooler fall weather sets in, when the leaves turn pale yellow, light orange, then brown as they begin to fall off. I looked for some of the tinier subjects to photograph; the photos below show some of the emerging leaves and the lines and curves of the tendrils as they search for places to attach. Sunlight, while very bright when I took these pictures, was filtered through the leaves, caused some harshness and clipping that I adjusted out of the photos as much as possible. At the same time, the sunlight also created some interesting background shapes and colors. Where you see a lot of white in the new leaves, that’s because they’re white on the bottom and shades of green and yellow on the top side.
The tendrils were a challenge to photograph, as the slightest breeze pushed them out of focus, and I’ll likely make another attempt at similar shots on a calmer day. The white clipping on the last photo was driving me crazy: I kept trying to de-emphasize it but couldn’t get it right without creating distracting artifacts in the image. I ended out emphasizing it instead by blurring and darkening the background, so it looks like a little flame instead of a … flameout.
These tendrils seem delicate but in reality are quite strong. The Catawba attaches itself tightly to the iron bars, and frequently latches onto the branches of Chinese fringe flower bushes that are growing nearby. I always thought it was just wind, coincidence, and a bit of stickiness that prompted the tendrils to attach to something, but I learned while researching this article that the plant follows a chemical and physiological process called thigmotropism to seek out and hook to attachment points. The tendrils can discriminate between the plant itself and other attachment points, favoring external attachments over self-attachment. This process can occur quickly: according to The Secret Life of Plants by Peter Tompkins and Christopher Bird:
“When the tendril … finds a perch, within twenty seconds it starts to curve around the object, and within the hour has wound itself so firmly it is hard to tear away. The tendril then curls itself like a corkscrew and in so doing raises the vine to itself.”
There is a description of this process, and some of the research behind it, at The Guardian, here: Scientists unwind the secrets of climbing plants’ tendrils; and an illustrated guide to the parts of a grapevine here: Grapevine Structure and Function (pdf).
Select any of the images below to begin a slideshow. As always: thanks for reading and taking a look!
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