Re: what color is Iris pseudacorus?

 

Gotcha! Was still asleep. Dark is absorbance. Still the signal stands out!

R

From: Sean Zera <zera@umich.edu>
To: iris-species@yahoogroups.com
Sent: Friday, November 22, 2013 10:37 AM
Subject: Re: [iris-species] what color is Iris pseudacorus?

 
I think the "colors" are backwards from what you'd expect. The entire flower is UV-reflective except the signal, which is yellow. Those "white" style-arms are the brightest ultraviolet part of the flower. I'm imagining a color scheme like a black chrysographes but with a yellow signal spot as well as the yellow veining in the falls.

Yellow must really stand out against UV, because it seems to be very common for "yellow" flowers to actually be bright ultraviolet with a bright yellow center. Dandelion is a good example.

Reptiles and birds also see UV. We've got excellent color vision for a mammal, though!

Sean Z


On Fri, Nov 22, 2013 at 10:54 AM, Rodney Barton <r*@yahoo.com> wrote:
 
Way cool! It's my understanding that bees can see in the UV and that many flowers are UV reflective. That plain, to us, signal is really calling out to the bees in UV!

Rod

From: Sean Zera <z*@umich.edu>
To: i*@yahoogroups.com
Sent: Friday, November 22, 2013 9:25 AM
Subject: [iris-species] what color is Iris pseudacorus?

 
No, seriously! As I'm sure many of you know, lots of flowers have ultraviolet patterns, invisible to us, that help them attract bees and other pollinators that can see ultraviolet. Check out this set of photos of Iris pseudacorus I came across online:


And the blog post they're from:

The left photo is natural light, while the other two are different wavelengths of UV. The bright areas are parts that reflect UV (the parts that would be ultraviolet-colored if we could see it), while the dark areas absorb UV (and so are not ultraviolet).

If my understanding is correct, this means that Iris pseudacorus is best described as ultraviolet, not yellow! It has bright ultraviolet style arms and paler ultraviolet falls with a bright yellow signal and yellow veining.

Sean Z





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