Structural colors in flowers

[DaveO]

If this paper doesn't make your head spin - rapidly - you are not reading it carefully enough

 

Signal or cue: the role of structural colours in flower pollination

https://academic.oup.com/cz/advance-article/doi/10.1093/cz/zoy096/5244970

 

Dave

[nfoto]

The predicted response developed - rapidly.

[Andy Perrin]

It sounds like (based on what I could make of their findings), the angular dependence has as much significance to pollinators as dichroic hotspots have to UV photographers.

[DaveO]

I came across this when I was looking to see what Adrian Dyer's group had been doing recently as he was one of the first to do UV images (on film in those days) of Australian native flowers. Hidden deep inside this paper is a figure

 

 

showing the UV Vis reflectance spectra of the subjects of this paper and I have posted my images of some of these:

 

Current Zoology, 2019, 1-15

Signal or cue: the role of structural colors in flower pollination

Garcia, Shrestha, Howard, Petersen and Dyer

 

(a) Alyogyne huegelli (Malvaceae)

http://www.ultraviol...ogyne-huegelii/

UV: Black petals

 

Solanum laciniatum (Solanaceae)

http://www.ultraviol...kangaroo-apple/

UV: Dark blue petals

 

(f) Pelargonium rodneyanum

http://www.ultraviol...ta-storks-bill/

UV: Light blue petals

 

What is interesting here is that they are at the "blue end" of the UV false colour spectrum whereas previous ones were at the yellow end.

 

One of these days I might make some sense out of it all

 

Dave

[Alaun]

Nice paper, but I miss the word "polarisation" in that context.

[DaveO]

This is another paper which has UV-Vis reflection spectra of various flowers, some of which whose images have been posted on this site

 

How to colour a flower: on the optical principles of flower colouration

C.J. van der Kooi, J.T. M. Elzenga, M. Staal and D.G. Stavenga

Proc. R. Soc. B 283: 20160429

 

https://royalsociety.../rspb.2016.0429

 

 

page 4

 

a) Hibiscus trionum (Malvaceae)

No UVP link

 

Borago officinalis (Boraginaceae)

No UVP link

 

c) Oenothera biennis (Onagraceae)

http://www.ultraviol...ening-primrose/

UV: Yellow petals

 

d) Papavera rheoas (Papaveraceae)

http://www.ultraviol...s-common-poppy/

UV: Yellow petals

 

Supplementary material

 

a) Cinchorum intybus (Asteraceae)

http://www.ultraviol...nother-example/

UV: Blue petals

Browallia americana (Solanaceae)

No UVP link

 

c) Solanum trisectum (Solanaceae)

http://www.ultraviol...m-buffalo-burr/

UV:yellow petals

d) Physalis philadelphia (Solanaceae)

http://www.ultraviol...d-groundcherry/

UV: dark yellow petals

e) Nuphar lutea (Nymphaceae)

No UVP link

 

f) Oenothera glazioviana (Onagraceae)

http://www.ultraviol...ening-primrose/

UV: Yellow petals

g) Petunia nyctaginiflora (Solanaceae)

No UVP link

 

h) Convolvulus arviensis (Convolvulacaeae)

http://www.ultraviol...field-bindweed/

UV: Dark blue petals

i) Lathyrus pratensis (Fabaceae)

http://www.ultraviol...adow-vetchling/

UV: Dark yellow petals

j) Geranium phaeum (Gerianaceae)

http://www.ultraviol...um-herb-robert/

UV: Bright blue petals

k) Caltha palustris (Ranunculaceae)

http://www.ultraviol...marsh-marigold/

UV: Black bullseye on yellow petals

l) Malva moschata (Malvaceae)

http://www.ultraviol...ta-musk-mallow/

UV: Light blue petals

 

So, there does seem to be a correlation, not a causation, between the UV-Vis spectra and those UV images which show yellow or blue false UV-colours