A very seasonal request for you, although if you live in London like me, there is nothing colourful and springy at the moment, thank you Mr Rain... Maybe I should do a post on the rain...
But for now, back to our beautiful subject: Flower colours...
A painter's palette
Flowers display such an array of colours for advertisement. Their sole hope of survival is by pollination. This can happen many ways using wind, water, animals, birds and insects. In the case of depending on the wind and water (eg. grass) there is no need of superfluous colour. But when the flowers need to attract pollinators, they have much competition so they have to look the best they can. Flowers are of different colours and different scents so different species can come and visit them, initiating a sort of fidelity card!
The shape of their petals and the precise location of their nectar, pollen and receptor all define the flower and help towards that purpose of species survival. Some flowers even mimic bees colours in order to attract them.
Evolution made this interaction beneficial for both species, the flowers and the pollinators.
Here below is a table showing some of the pollinators and their "meal" of choice:
|Taken from Pollination Biology: Biodiversity Conservation and Agricultural Production|
Where does the colour come from?
All those different colours come from a certain type of molecule contained in the cells vacuoles, these molecules are called chromophores.
There are many types of chromophores, the main category is called flavonoids because they contribute to the colours white, yellow, orange and red to blue. Other important categories of chromophores include carotenoids (yellow, orange, red) and chlorophylls (green). But there are many more and each category comprise their range of molecular difference to account for each variety.
What do we see?
Chromophores work by absorbing and reflecting light at different wavelenghts so we and others perceive different colours. Note that some flowers contain chromophores that work not only in the Visible wavelenghts but also in the UV wavelenghts so only certain insects can see them!!
What's a wavelenght?
You can think of light as being a kind of wave, similar to the waves in the ocean. The distance between the top of one wave and the top of the next wave is called a wavelength. Different colors have different size wavelengths. Violet has the shortest wavelength. Red has the longest wavelength. Wavelengths of colors are measured in nanometers, or billionths of a meter.
So, that's it for this sexy new post. I didn't write about Pollination in details as, I don't know about you, but I was hammered with it when I was at school so I don't fancy revisiting it too much... lol
But if you insist, I'll obviously be glad to do it for you...