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Plants Dance

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Have you ever wondered how that morning glory vine knew how to find a support and twine around it? Or, for that matter, how roots know to grow down and stems know to grow up? And while we all know that plants follow light – how exactly do they do that?

For those of us who enjoy our geekery, it’s fun finding out more about these things. But even if you’re not a geek, knowing how your plants move adds a dimension to gardening, and might help you garden better, too. And just about everyone loves watching time-lapse photography movies, which are the core of this post. You can watch plants dance.

The forces that move plants really are beyond our ken. Well, the forces of nature are pretty much beyond our ken (especially our own natures). But humans do like to watch and name things. Science (one of the big areas for watching and naming, but not the only one) – science has a name for the ways plants move: tropisms.

There are different kinds of tropisms, but I think it would be much more fun for you to watch them than for me to tell you about them. This Indiana University site has several very short movies – each of them less than a minute. You can watch corn sprouts bend down, worshipping light in a ceremonial circle, or corn roots that know which way is down, even when they’re turned on their sides. Arabidopsis and tomato sprouts gracefully quirk into arabesques toward different kinds of light. Take five minutes at the Plants in Motion website; it’s better than a coffee break for a rush of energy.

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Morning glory flowers lean into the sun: phototropism

 

My favorite movements are what this site calls nastic movements, movements plants make which aren’t necessarily in the direction of the stimulus (roots going down to ground, stems bending toward light). If  you go to this page of the site, you can watch a morning glory vine wave around, find a support, and twine around it.

Of course since it’s human beings making the categories here, there’s some argument about whether this is a nastic movement – those are the movements that don’t go toward (or away from) the stimulus. Some people call this dance of the morning glories thigmatropism – which means that when the reaching plant hits a solid object, it starts twining (or in the case of plants with suction cups, like ivy, sticking).

If you like intimations of horror without the gore, there’s an episode of a venus fly trap closing (a nursery manager once taught me how to stimulate the center, not the edges, of their traps. And using a bigger instrument (such as your finger) will get you better results than the little metal tool in this movie).

To me, the most spectacular of these nastic movements are the young and old arabidopsis (what is arabidopsis?) plants. They wave, they bend, they whirl: what’s the force moving them? Their own plant cells, elongating more on one side than another. When you watch the 10-second movie, they look as if they are blowing in a high wind. But the wind is all inside them. Inside their secret lives.

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{ 11 comments… add one }

  • Frances November 5, 2009, 2:46 am

    Hi Pomona, fascinating topic, tropisms. As a young elementary school student, movie day was my favorite in science class. Often there would be the time lapse photography showing bean seeds sending roots down, sunflowers following the light and flowers crumpling when finished with their business. It is mesmerizing. Thanks for providing this site, it will be checked out soon. :-)
    Frances

  • Sylvia (England) November 5, 2009, 3:26 am

    Pomona, your pictures of morning glory are lovely. I have difficulty growing them, I think they need a warm summer – so perhaps next year. At least it would be a consultation for having a hot summer!

    I still haven’t planted any bulbs and now the ground is very wet. Pots again this year I think!

    Best wishes Sylvia (England)

  • tina November 5, 2009, 4:56 am

    Thanks for finding all those links. I plan to explore them in a bit. I received a time lapse camera and have been busy experimenting so I’d like to see them. I want to know which is the best interval:)

  • Pomona Belvedere November 5, 2009, 8:24 am

    Hi Frances, we didn’t get these great movies in science, you were lucky! All I remember is the time we persuaded the science teacher to let us run the one of the volcano erupting – backwards.

    Sylvia, even in my climate I find morning glories are and end-of-summer/early fall phenomenon, but I love them so much they’re worth it. I plant most of my bulbs in pots and they do very well there (definitely a lot better than in sodden mud, which we also have a lot of in winter).

    Tina, there is actually info on this site as to how to do time lapse photography, including the intervals they use. If you go to the first link, you’ll get the main menu; “how to do time lapse photography” (or some such title) will be near the bottom.

  • Daffodil Planter November 5, 2009, 9:42 pm

    Sounds like a site that will be bookmarked and sent to friends–thank you! Now, asking Ms. Science–what is the difference between phototropic and heliotropic?

  • Steve November 6, 2009, 3:58 am

    Very cool topic and illustrations, Pomona. It reminds me of draping myself around a bar sto- wait, wrong place. 😉

    I love your “geekery”, I have to confess. I identify, I am sure.

  • susan (garden-chick) November 7, 2009, 9:37 am

    If morning glories leaning towards the sun is an example of phototropism, then what is the overwhelming pull the kitchen seems to have on me during the day when I should be working called?

  • sunny November 7, 2009, 8:39 pm

    This year I tried “Mexican sour gherkin” from Kitchen Garden Seeds. It took ages to gain momentum but once it was warm and onto a trellis it was an animal. One day I watched as the tendrils strained and quivered to reach a twig and wrap around. I returned minutes later to see it spiraled firmly, really pulling itself up. Talk about might… Good to see your posts again!

  • Pomona Belvedere November 8, 2009, 9:56 pm

    DP – phototropic means movement following light, and heliotropic means movements tracking the sun. (They call me Dr. Science. That’s because I may someday have an associate’s degree – in science.)

    Steve – is draping yourself around a barstool geotropic or beerotropic? Do you have any time-lapse videos we could see on your blog?

    Susan – Procrastination.

    Sunny – I envy you your gherkin-twining moment. How cool is that?

  • catmint November 9, 2009, 1:31 am

    Hi Pomona, haven’t visited you for ages. I love the mix of science and art in this post. I have awarded you the honest scrap award. cheers, catmint

  • sherdane williams December 4, 2010, 6:00 am

    As a college student I find this site very amazing, it have helped me alot with my activities. I’m loving the topics too. I’m aiming at being an environmentalist someday so I’m hoping this site would help shape my future.

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