Peltate trichomes

I was in Delaware in March for a family reunion. Spring having emerged from winter the week before, there was much floral and insect activity.  All the usual suspects started blooming. I went into a thicket down my cousin’s backyard and found this plants with interesting leaves with brown spots all over underneath.

peltate1
At first I thought it was some kind of infection, but the spots were too regularly distributed. Under the foldscope each of those brown spots had a fan-like structure and interestingly they always surrounded stomata .

peltate2

Upon scanning the field, I found several developmental stages of this structure.  Video follows where I am discussing this with some kids.

It was then I remembered this remarkable post on Peltate trichomes by Manu, and his analysis on how this structure is used to trap moisture. See https://microcosmos.foldscope.com/?p=13025. The physics of this process as explained by Manu is really interesting.

Currently based on my reading, I suspect this is a  member of the olive family (Olea), although the genus requires a bit more work, and another trip to Delaware. Dont forget to look under leaves, I have always found surprises.

One Comment Add yours

  1. Manu Prakash says:

    Wow wow wow!! What a remarkable find @Laks. Loved your curious explorations live.

    You are Igbo about the Trichomes. What’s interesting is that mechanically they have a “gate” like structure right under the Trichomes which opens because of the buckling of the Trichome in modifier (with capillary forces pulling it down). It’s remarkable that they are so mechanical.

    I had never thought about life stages – but it makes perfect sense for them to mature – since from a material properties point of view – you need the right stiffness to get the mechanism to work.

    Wonderful find 🙂

    Cheers
    Manu

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