Towards the end of March, I was returning from a trip to the postbox at the Railway Station when I came across this 'carpet' of lesser celandine along the Great Western Way foot/cycle path.
William Wordsworth wrote three poems about this humble perennial of the buttercup family which is one of the first woodland flowers to appear in Spring. Fun fact: one of its local names is 'Pilewort' because it was used for the treatment of haemorrhoids. In most gardens it is a bit of a pest and quite difficult to get rid of; my neighbour has tried both vinegar-based weedkillers and a heat gun weeder but they always come back. There are patches dotted around my garden but I think you just have to enjoy them while in bloom and they are easy enough to pull up and add to the compost bin.
Anyway, getting back to my walk, it got me thinking why is the colour yellow so dominant in Spring flowers? Within a few yards of this patch of lesser celandines were jasmine, dandelions, mahonia and Japanese Rose (Kerria japonica):
Not forgetting the tulips, daffodils, primroses, cowslips, etc, etc.
Flowers need pollinators so presumably yellow is peculiarly and particularly attractive to the most abundant pollinators at this time of year which tend to be flies rather than bees. The fact that sticky fly strips/traps are usually yellow supports this hypothesis. However, I didn't think yellow vision was especially strong in insects as they tend to see the higher frequencies (lower wavelengths) of the spectrum up to and including ultraviolet.
A study in 2009 reported darker colours (reds and blues) absorb UV better than yellow so perhaps yellow flowers provide the best contrast, in the lower light conditions of Spring, with the important parts of the flower's reproductive system (pistil and stamen).
Any other suggestions welcome.