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Osteospermum sp. [Pink Whirls]

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#1 Steven B.

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Posted 15 April 2017 - 13:21

Bouedec, S. (2017) Osteospermum sp. L. (Asteraceae) Pink Whirls. Flowers photographed in visible, ultraviolet, infrared and UV+B+G light.
http://www.ultraviol...sp-pink-whirls/

Jardin Exotique & Botanique de Roscoff, Roscoff, Finistère, Brittany, France
14 April 2017
Cultivar in botanical garden

Synonyms:
  • Osteospermum 'Pink Whirligig'
Common Names:
  • African daisy 'Pink Whirls'
Comment:
The flowers of this African daisy are striking pink pinwheels. Circling a central disc, the petals are broad at the base, then tubular, then broad at the tip, like little spoons. Frequently grown as an annual ‘Pink Whirls’ is descended from a perennial native to South Africa that is favored by breeders in search of showy flowers for gardens and greenhouses.

Reference:
1. Royal Horticultural Society (2017) Osteospermum 'Pink Whirls'
https://www.rhs.org....ls?plantid=3646
2. Jardin Exotique et Botanique de Roscoff (April 2017) Osteospermum 'Pink Whirls'
http://www.jardinexo...inga-cream.html

Equipment [Nikon D3200-broadband + EL Nikkor 105mm f/5.6]

Visible Light [f/11 for 1/25" @ ISO-400 with S8612(2.5mm) filter in sunlight]
Attached Image: 800DSC_7946.jpg

Ultraviolet Light [f/11 for 4" @ ISO-400 with Canon 199a modified Flash and Baader UV-Pass Filter]
Attached Image: 800DSC_7948.jpg

Infrared Light [f/11 for 1/50" @ ISO-400 with Hoya R72 filter in sunlight]
Attached Image: 800DSC_7953.jpg

UV+Blue+Green [f/11 for 2" @ ISO-400 with S8612(2.5mm) + U-330(1.5mm) filters in sunlight]
Attached Image: 800DSC_7947.jpg

Edited by Steven B., 15 April 2017 - 14:15.

Steven B.

#2 Andy Perrin

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Posted 15 April 2017 - 15:35

Wow, those are quite interesting right across the spectrum, even in infrared!

#3 Cadmium

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Posted 15 April 2017 - 23:19

Yeah, I really like that IR shot.

#4 Andrea B.

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Posted 15 April 2017 - 23:50

This is such an interesting flower. Those curled petals are amazing! In recent years several of the African flowers have become very popular here in the US for summer gardens and patio pots. I always try to grow a few.

I'm happy to see the inclusion of IR and UV+B+G. Sometimes I don't have the time to shoot an array of filters due to travel constraints, but try to when I can.
Andrea G. Blum
Often found hanging out with flowers & bees.

#5 Steven B.

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Posted 16 April 2017 - 20:51

For sure this flower is amazing !
I try to take time to get multispectral shoots of a flower in case I miss interesting details that could be useful for those studiyng them.
For that one I'm surprise by result of UV shoot showing a nice kind of yellow at bottom of petals.
But one thing I can't understand and I hope somebody here could answer my question... why petals of a young (or closed) Osteospersum are showing the same IR blue as stamens of an open one ?

Edited by Steven B., 16 April 2017 - 21:01.

Steven B.

#6 Andy Perrin

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Posted 16 April 2017 - 22:32

Yeah, and I was just wishing you had a photo of the back of the petals of the older, open ones!

#7 Andrea B.

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Posted 17 April 2017 - 13:17

There are some flowers for which the top surface (aDaxial side) of the petal looks different in UV/IR from the bottom surface (aBaxial side) of the petal. In differing amounts, UV/IR wavelengths are reflected from, refracted by and transmitted through a petal because of the petals' aDaxial surface conical cells, micro structures inside petal tissues and pigment chemistry (and other factors).

As for why this happens in a particular flower such as this Osteospermum, we would have to know much more about its structure and pigment and how they interact. If this flower is perhaps absorbing a bit more high red or low IR in its false-blue areas, then it could perhaps be because the extra bit of IR "heat" helps the disk florets open to produce pollen?? If so, then you would have to ask why other flowers do not exhibit this kind of (moderately) IR-absorbing center. One question leads to another....... :D

The scientific botanical literature is vast. But, you could try a search on "IR-absorbing disk in Asteraceae" to see if anything pops up.

******

Bjørn has encouraged those who enjoy shooting floral UV-signatures to always include a shot of the the aBaxial side.
Andrea G. Blum
Often found hanging out with flowers & bees.