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Interesting paper about surface structures in flowers and UV

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#1 UlfW

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Posted 08 January 2021 - 08:08

https://www.beilstei...-4286-10-45.pdf
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#2 colinbm

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Posted 08 January 2021 - 08:23

Structural Colour is fascinating....

#3 Andy Perrin

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Posted 08 January 2021 - 15:35

That’s an interesting result. The replicas didn’t get nearly as dark as the originals, so obviously this is some combination of pigment and structural color, not just structure.

Also interesting was the Erodium manescavii flower which is the first flower I’ve ever seen that has the UV bullseye but is not yellow. Has this flower been imaged on the board before?

Edit after seeing DaveO's comment: wow, I forgot you posted that! And that I'd seen it before...um, time to lay off the booze.

Edited by Andy Perrin, 09 January 2021 - 01:29.


#4 DaveO

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Posted 08 January 2021 - 23:31

Been there, done that

https://www.ultravio...__fromsearch__1

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#5 UlfW

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Posted 09 January 2021 - 12:23

DaveO, It was interesting the first time I read it too, before completely forgetting your post.
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#6 Andrea B.

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Posted 15 January 2021 - 19:45

Birna and I have certainly seen some kind of structural effect in the UV reflectivity of floral subjects. The best examples we saw were when we were photographing the poppies in the US deserts (Arizona, IIRC). They are deep black in UV but show these interesting UV-bright streaks and flashes as they toss about in the wind. Other flowers like spring blooming crocus also show this. We have been calling it "iridescence" and remark on it often in floral topics.

I'm quite sure we aren't the only UV floral photogs who have observed this. :grin:

The explanations in Nanotechnology paper are quite interesting. That is not the first paper to discuss structural color, but their work with the scanning electron microscope really does serve to "prove" (as they put it) how the structural color actually works. This is one of the papers I'm going to print out and study in depth.

Thank you for the link, Ulf.



I think I should have somewhere here on UVP a small board just to collect links to papers. We have a lot of them now. I had been trying to mark such references with a title header like [Article] or [Paper] in the References section. Maybe I should continue that. (I need more hands !!!)



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#7 Stefano

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Posted 15 January 2021 - 19:52

Andrea, that's interesting. I would love to have such a flower to record a video of it.

#8 Andrea B.

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Posted 15 January 2021 - 20:05

In the spring, Italy has lots of blooming red poppies. I saw these around the colosseum in Rome, which I am sure is not the only location in Italy where they bloom. I also saw them along railroad tracks. They were *beauriful*. So in the spring, start looking. Also check with florists and garden plant stores in the spring for "Iceland" poppies (yellow, orange, pink) which is a popular spring garden flower here which I'll bet you can also get.

Birna has a video of the desert poppy in UV. I'll see if we can figure out how to link it. Don't know if she is available right now, but I'll check.
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#9 Stefano

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Posted 15 January 2021 - 20:10

I saw red poppies occasionally in my area. They aren't very common, but they do grow. Will give a try if I can.

#10 Andy Perrin

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Posted 15 January 2021 - 22:23

All I know is that they have them in Belgium (because of the poem).

#11 dabateman

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Posted 15 January 2021 - 23:04

You can order the opium variety from Washington and California states. I have seen them in medicinal catalogs. The seeds, dried flowers or live plants.

#12 Andrea B.

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Posted 16 January 2021 - 07:04

Seems to be that some US states don’t permit the import of Papaver somniferum from other states. Hard to believe that anyone is going to launch a major morphine manufacturing factory or neighborhood opium den from a couple of garden poppy plants. But hey, ya never know.......

California Poppies, which are Eschscholzia californica, are easily grown from seed. Gotta start them early though. They are deep black in UV with structral “flashes”. Going to look or link now. https://www.ultravio...can-gold-poppy/




Stefano, I screwed up a comment to you. I don’t think those red Italian poppies show UV-black. While they are quite nice to photograph anyway in any wavelength, you might find them to be a UV false yellow. I certainly don’t know all the possible Euro poppies, but I think those ubiquitous red ones are Papaver rhoeas. Going to look for link now. https://www.ultravio...s-common-poppy/




Here is a Desert Poppy for which I managed to capture a UV still showing a flash. https://www.ultravio...ert-gold-poppy/
It’s in the 2nd UV photo.


.
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#13 dabateman

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Posted 16 January 2021 - 07:17

Here is s good mix:
https://strictlymedi...ar-turkish-red/

#14 Andrea B.

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Posted 16 January 2021 - 07:26

My goodness look at that huge pod!
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#15 Andrea B.

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Posted 16 January 2021 - 07:36

I really got wrapped up in that website. Let’s just say that some of the “strictly medicinal” seeds are strictly hallucinogenic and some are more than just a little bit poisonous!! Lots of great wildflower seeds though.
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#16 Stefano

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Posted 16 January 2021 - 14:35

View PostAndrea B., on 16 January 2021 - 07:04, said:

Stefano, I screwed up a comment to you. I don’t think those red Italian poppies show UV-black. While they are quite nice to photograph anyway in any wavelength, you might find them to be a UV false yellow. I certainly don’t know all the possible Euro poppies, but I think those ubiquitous red ones are Papaver rhoeas. Going to look for link now. https://www.ultravio...s-common-poppy/
I didn't know a visible red flower could be UV-yellow. I always thought only yellow flowers could appear UV-yellow. You always learn here.