Pappose

A plant that bears a pappus (or more likely, pappi) is said to be pappose. With purpose.  And no porpoises.  (Please stop me before I go any further).

What’s a pappus, you say?

See this dandelion flower (actually a cluster of florets) that has gone to seed?  If you’ve ever held one in your hand and pulled a single seed away from the head, and then eyeballed it really closely…you’ll see that the fine, fuzzy white stuff on top (actually a modified calyx) sits above the thin brown seed like a skeletonized parachute.  The parachute calyx is a pappus, and although you can’t see all of them really well without a microscope, if you could count, you’d find that there are around 100 bristle-like filaments comprising each one. As dandelion seed is dispersed via wind, this pappus structure proves very useful, able to carry the seeds up to 100 kilometres (62 miles).

SONY DSC

Dandelions aren’t the only plants that are pappose – you’ll find that most members of the daisy (Asteraceae) family are as well – but I’ve got one more fascinating dandelion pappus story to share before I sign off on this post. Get this: In 2018, researchers at the University of Edinburgh (using some cool gadgets such as a wind tunnel, lasers, high speed cameras, and x-ray microtomography) discovered the precise number of and the specific way the filaments in each pappus are arrayed makes even more of a difference to the efficiency of wind dispersal of the seeds than previously thought. It was an accepted theory that the resistance (drag) of individual filaments to wind makes dandelion seed so good at flying. It turns out that the way that moving air flows around each individual filament – and the filaments around it – creates a sort of stabilized vortex ring, allowing the seeds to stay buoyant for an impressive time and over long distances. You can read all about the physics of this amazing adaptation here.

Sources:
Martina Ribar Hestericova. “Dandelion seeds create vortexes to remain aloft.” Physics World. October 22, 2018. https://physicsworld.com/a/dandelion-seeds-create-vortexes-to-remain-aloft/.
Nature. “Revealed: The extraordinary flight of the dandelion.” October 17, 2018. https://www.nature.com/articles/d41586-018-07032-6.

20 responses to “Botany word of the week.”

    1. Sheryl @ Flowery Prose Avatar

      I’m so glad you enjoyed it! I hope you’re doing well.

  1. shoreacres Avatar

    And milkweeds! We played with milkweed pappi as much as those of the dandelions when we were kids. This was a good word choice. I was especially surprised to read that the pappus is a modified calyx. I’m still not sure I understand that, since I’m so used to thinking of the calyx as the sepals.

    1. Sheryl @ Flowery Prose Avatar

      Some gardeners are growing milkweed here but it’s not commonly found wild…so I’m not used to it! But they would definitely be just as much fun for children to play with as dandelions….

  2. Laurie Graves Avatar

    What a great way to start the week! I learned a new word and the concept behind it. Now, to remember it. 😉

    1. Sheryl @ Flowery Prose Avatar

      I hope I can get a few more of these types of posts out over the next while! I think I will have to move to a monthly format, though….

  3. natuurfreak2 Avatar

    Heel interessant en weer wat nieuws geleerd

  4. gardeninacity Avatar

    Excellent word! I will appreciate dandelions more.

    1. Sheryl @ Flowery Prose Avatar

      They are fascinating, even if they aren’t always welcome! I hope you and your family are doing well.

  5. automatic gardener Avatar

    I learned something new today.

  6. tonytomeo Avatar

    I wrote about horticultural slang that my colleague down south and I invented over the decades to compensate for lack of some technical lingo. With all the proper horticultural terminology, you would think that everything is covered.

    1. Sheryl @ Flowery Prose Avatar

      How inventive! Do you have a link to your post or article about this? I would enjoy seeing it!

      1. tonytomeo Avatar

        Actually, I can not find it. I am sort of wondering if it made it into the blog. All I found, was this: https://tonytomeo.com/2017/10/08/politically-incorrect-horticulture/

  7. arlingwoman Avatar

    I love learning these words!

    1. Sheryl @ Flowery Prose Avatar

      I am so happy you enjoy these posts! I hope you’re doing well.

      1. arlingwoman Avatar

        So far so good. Pretty much been staying home since March 13, working from home and it’s frustrating, but not contaminating! I hope you’re doing well, too!

  8. Born To Organize Avatar

    This is a fascinating post, Sheryl. Thanks for sharing.

    1. Sheryl @ Flowery Prose Avatar

      I’m so pleased you enjoyed it! Hope you and your family are doing well, thinking of you.

      1. Born To Organize Avatar

        Thank you, Sheryl. We are all doing well and sheltering in place. I’m home with my husband and eldest son. My younger son is sheltering in place and take all classes on line at university. I miss him. How are you?

I’m delighted to hear from you – thanks so much for your comments!

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